---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 06/08/20: 32 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:06 AM - Re: DIY replacement for Rotax voltage regulator (Rowland Carson) 2. 05:19 AM - Re: Re: digest distribution stopped? (John M Tipton) 3. 08:05 AM - Re: DIY replacement for Rotax voltage regulator (GTH) 4. 08:21 AM - Re: Physical construction of Z101 engine bus & battery bus (Robert L. Nuckolls, III) 5. 09:08 AM - Re: Physical construction of Z101 engine bus & battery bus (Ken Ryan) 6. 09:29 AM - Re: digest distribution stopped? (farmrjohn) 7. 09:31 AM - Re: Physical construction of Z101 engine bus & battery bus (Foghorn Inc) 8. 10:40 AM - Exploring a Different Way to Wire Avionics (Jeff Luckey) 9. 10:49 AM - Z16 and three position switch (William Daniell) 10. 10:55 AM - Re: Physical construction of Z101 engine bus & battery bus (user9253) 11. 11:15 AM - Re: Exploring a Different Way to Wire Avionics (James Quinn) 12. 11:31 AM - Breaker (Sebastien) 13. 11:35 AM - Re: Exploring a Different Way to Wire Avionics (Kent or Jackie Ashton) 14. 11:41 AM - Z101 main alt wiring (David Carter) 15. 12:00 PM - Re: Exploring a Different Way to Wire Avionics (Jeff Luckey) 16. 12:06 PM - Re: Exploring a Different Way to Wire Avionics (Alec Myers) 17. 12:15 PM - Re: Breaker (Jeff Luckey) 18. 12:19 PM - Re: Exploring a Different Way to Wire Avionics (Charlie England) 19. 12:26 PM - Re: Z101 main alt wiring (Charlie England) 20. 01:08 PM - Re: Breaker (Sebastien) 21. 03:20 PM - Re: Breaker (Charlie England) 22. 03:42 PM - Re: Physical construction of Z101 engine bus & battery bus (Charlie England) 23. 04:09 PM - Re: Physical construction of Z101 engine bus & battery bus (Sebastien) 24. 04:09 PM - Re: Breaker (Sebastien) 25. 04:22 PM - Re: Physical construction of Z101 engine bus & battery bus (Ken Ryan) 26. 04:31 PM - Re: Physical construction of Z101 engine bus & battery bus (Robert L. Nuckolls, III) 27. 04:56 PM - Re: Physical construction of Z101 engine bus & battery bus (Charlie England) 28. 04:59 PM - Re: Physical construction of Z101 engine bus & battery bus (Alec Myers) 29. 05:07 PM - Re: Physical construction of Z101 engine bus & battery bus (Ken Ryan) 30. 05:15 PM - Re: Physical construction of Z101 engine bus & battery bus (user9253) 31. 06:08 PM - Re: Exploring a Different Way to Wire Avionics (donjohnston) 32. 06:56 PM - Re: Re: Exploring a Different Way to Wire Avionics (Charlie England) ________________________________ Message 1 _____________________________________ Time: 04:06:12 AM PST US From: Rowland Carson Subject: Re: AeroElectric-List: DIY replacement for Rotax voltage regulator On 2020-06-08, at 01:25, GTH wrote: > Thanks for your offer. > > I was able to open the files with a free version of Eagle I downloaded last week, and converted them to gerber files that can be read by any CAD program - and any vendor for that matter. > But I'm not at all familiar with Eagle so I'm not sure I did it right. > So if you or anyone can provide verified gerber files I'd willingly publish them so one can directly order from a PCB vendor. Gilles - I have sent to Bob the (several) files that kind folk converted for me to be readable by the current version of EAGLE for Mac. I expect he will announce when they are loaded alongside the other files for the Miller regulator. I=99ve had a look at the export possibilities provided by my version of EAGLE (9.6.1) and the file format possibilities do not include Gerber - see attached screenshot. Maybe someone can say if one of the options shown would be more universal than a .BRD file. Or once the .BRD files are put up by Bob, folk can play with them and try translating to Gerber. in friendship Rowland | Rowland Carson ... that's Rowland with a 'w' ... | http://www.rowlandcarson.org.uk | Skype, Twitter: rowland_carson Facebook: Rowland Carson ________________________________ Message 2 _____________________________________ Time: 05:19:16 AM PST US From: John M Tipton Subject: Re: AeroElectric-List: Re: digest distribution stopped? Most if my AeroElectric emails go to the junk folder, have you checked there John Sent from my iPad ----x--O--x---- > On 8 Jun 2020, at 8:06 am, BobD wrote: > > > > farmrjohn wrote: >> Has the digest distribution stopped? I haven't received one for some time now. > > > This happened to me a couple if times over the years. It turns out the Servers that the Matronics list uses are a bit finicky about the other e-mail Servers they will talk to, and the solution was to change the e-mail address you use. Since I changed mine to a gmail.com address, I've not had a problem. > > Hope it works for you. > > -------- > Bob Dawson > Europa XS TG || 912 ULS || G-NHRJ || Dynon Skyview || PilotAware || SmartAss3 > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=496673#496673 > > > > > > > > > ________________________________ Message 3 _____________________________________ Time: 08:05:31 AM PST US Subject: Re: AeroElectric-List: DIY replacement for Rotax voltage regulator From: GTH /Le 08/06/2020 13:04, Rowland Carson a crit: / > / > / > / > / > /Ive had a look at the export possibilities provided by my version of > EAGLE (9.6.1) and the file format possibilities do not include Gerber > - see attached screenshot. Maybe someone can say if one of the options > shown would be more universal than a .BRD file. Or once the .BRD files > are put up by Bob, folk can play with them and try translating to Gerber./ Hi Rowland, Thanks for that. If I recall correctly I tried the CAM option(s) to generate the gerber and .drl files. Will post them on the webpage for anyone to download. -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr ________________________________ Message 4 _____________________________________ Time: 08:21:56 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus At 09:20 PM 6/7/2020, you wrote: >SDSEFI recommends 2 alternators and a battery. If you have a single >battery and alternator they recommend an additional battery that is >only connected to the ENG BUS for an emergency. The recommended >procedure is to charge that battery on the 1st of the month and load >test yearly. Not a particularly definitive battery management philosophy. "Charging once a month" whether needed or not? "Load test" is not specific . . . what kind of load and for discovery of what condition? Internal impedance (cranking) or capacity (endurance)? How would that knowledge augment the pilot's prospects for dealing competently with an alternator failure? How would these batteries be selected and configured in the architecture? What would the plan-b checklist look like? Recall that the ultimate goal for crafting a failure tolerant architecture is to prevent any single failure from becoming an emergency. That goal cannot be realized without first knowing the ENERGY requirements for the TOTAL constellation of hardware necessary to conduct a comfortable termination of flight within some ENDURANCE value determined by the BUILDER . . . not by some 'authority from afar' who will never ride in the airplane. Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:08:02 AM PST US From: Ken Ryan Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus Bob, you said: "If you have TWO properly maintained batteries, in all likelihood, you'll be carrying around $twice$ the hardware with virtually no value added to the ship's overall reliability." Help me understand why the following statement is not correct: If you have TWO properly maintained alternators, plus a battery (sized for minimum endurance requirements) in all likelihood, you'll be carrying around $twice$ the hardware with virtually no value added to the ship's overall reliability. Ken On Sun, Jun 7, 2020 at 6:56 PM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 05:26 PM 6/7/2020, you wrote: > > I am not speaking to any engine manufacturers recommendation (although th e > Honda Viking manufacturer does recommend two batteries. I just thought > I was applying logic -- if dual alternator=C3=82 + battery (triple power source) > is desirable for electrically=C3=82 dependent engines, wouldn't that reas oning > imply that if the second alternator is not practical, a second battery > could be used as the third power source? I could ask you a similar > question: > Are not two independent power sources (battery and alternator) sufficient > to meet the needs of the electrically=C3=82 dependent engine. Obviously y ou > saw value in adding the second alternator. Why no value in adding the > second battery? > > > Excellent question. > > It's a problem in energy budgets combined with > efforts to assure continued airworthiness. > > The airplane cannot do without a battery if > you're going to have a starter. Depending on > your planned mission profiles, you will want > to size the battery (1) for cranking then > (2) minimum endurance in alternator-out modes. > > This study gave impetus for the creation of > the endurance bus . . . a fast and predictable > way to economically tap known quantity of energy > stored in the battery's chemistry. > > Z13/8 was a small but significant amplification > of that idea . . . the second alternator's endurance > had no practical limits. Hence, energy on the chemistry > just might be held completely in reserve for > descent and approach to landing. > > Z13/20 (and the aux alternator option on > Z101) expanded the Z13/8 endurance opportunity > by a factor of 2.5 or better. > > Okay, suppose the drive pad isn't available. > We are still charged with identifying and the > delivering to energy required to comfortably > terminate a worst-case mission. > > This means that as a part of routine maintenance > the ship's chemistry needs to be monitored for > capability. We could certainly store that energy > on TWO devices but to what advantage? If we're laboring > under the notion that a battery can suddenly become > unavailable during one tank of gas, then we have > to assume that EITHER battery can roll over and > die . . . okay, how would that failure be > annunciated . . . how would remaining energy be > managed . . . ? > > I think that's the scenario anticipated by the > folks that crafted that battery manager with a > full-wave rectifier that -anded- two, completely > isolated batteries together. Assume the alternator > has quit and some time later one battery > craps out. How does the pilot become aware of the > problem and what kind of energy juggling issues > are presented when the available energy drops > to half? This assuming he really knows that the > two batteries were performing equally and has > recently quantified their condition, he now > has to come up with a new "plan C?" and perhaps > declare an emergency. > > This scenario first assumes TWO critical failures > during the consumption of one tank of fuel . . . > about 3-4 hour window. Part 23 certs don't > get concerned with dual failures at all. > Part 25 and heavier will wade into the reliability > quagmire with mountains of computer generated probability > studies that get 'worked' on until somebody > finally sprinkles the holy water and off they > go. > > Ask Capt. Sullivan what he thinks about > reliability studies . . . > > https://www.youtube.com/watch?v=HKJ1lIh2Cgk > > So we're left to our own devices which in reality > are not so bad. > > The short answer is: A diligently maintained > battery is the most reliable source of energy > on the airplane. Replacing it when ability > to store energy drops below some benchmark > (generally 75 to 80% of new) means that it > always cranks the engine and will provide a > quantified option for dealing with alternator > failure. Two batteries just doubles your > preventative maintenance labor. Further, > you need to decide if plan-b can reliably > depend on the sum total of energy in two > batteries . . . or will they be sized to > independently step up to the task? The > second option calls for 2X the battery > weight and volume; the first option complicates > calculations and switching operations for > carrying out a plan-b that shouldn't ever > happen. BOTH options still demand good > preventative maintenance. > > Just as you KNOW fuel aboard when you launch, > you also need to know Watt-Hours aboard > no matter how many batteries you're carrying. > > If you have TWO properly maintained batteries, > in all likelihood, you'll be carrying around > $twice$ the hardware with virtually no value > added to the ship's overall reliability. > > Bob . . . > ________________________________ Message 6 _____________________________________ Time: 09:29:21 AM PST US Subject: AeroElectric-List: Re: digest distribution stopped? From: "farmrjohn" I've checked the junk folder, nothing there. I re-subscribed and got a confirmation email from Matronics, but no digest yet. Will continue watching both inbox and junk folder. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=496680#496680 ________________________________ Message 7 _____________________________________ Time: 09:31:42 AM PST US From: Foghorn Inc Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus Bob, Here is what the SDS EFI manual suggest. I didn=99t hit every point in my email to the group. I personally have the 2 ALT/1 BATT option. Backup Electrical Power Considerations Electrical power is necessary to keep the ECU, fuel pump, coils and injectors running so it=99s important to think about having a backup power source available. In the case of Lycoming engines, a small backup alternator like the B&C SD8, SD20 or BC410-H SD can be fitted to a vacuum pump pad. On other engines, a small second alternator could be fitted. If you don=99t have a second alternator, you should have a small backup battery. Sizing would depend on your typical/ maximum distance between airports. Current draw of the pump, ECU, injectors and coils would be around 12 to 14 amps. A 12 amp/hour battery should give you a solid 30-40 minutes of flight time, just running the engine electrics. An 18 amp/hour one, around 1 hour. We want to be able to sustain at least 10 volts to the electrics. We=99ve found the most reliable, simple and light way to get backup battery power to the engine electrics is a single 12 to 14 gauge wire running from the backup battery, through a 30 amp ATO fuse, to a heavy duty switch, to an emergency buss where all the engine electrics can receive power. Simply charge the backup battery every 30 days and load test annually. If you have the recommended check engine light fitted, it will warn you any time the battery voltage falls below 12.5V. You can monitor battery voltage in Gauge 3 mode. Jeff Parker > On 8Jun, 2020, at 11:18, Robert L. Nuckolls, III wrote: > > At 09:20 PM 6/7/2020, you wrote: >> SDSEFI recommends 2 alternators and a battery. If you have a single battery and alternator they recommend an additional battery that is only connected to the ENG BUS for an emergency. The recommended procedure is to charge that battery on the 1st of the month and load test yearly. > > Not a particularly definitive battery management > philosophy. "Charging once a month" whether needed > or not? "Load test" is not specific . . . what kind > of load and for discovery of what condition? Internal > impedance (cranking) or capacity (endurance)? > How would that knowledge augment the pilot's > prospects for dealing competently with an alternator > failure? > > How would these batteries be selected and configured > in the architecture? What would the plan-b checklist > look like? Recall that the ultimate goal for crafting > a failure tolerant architecture is to prevent any > single failure from becoming an emergency. > > That goal cannot be realized without first knowing the > ENERGY requirements for the TOTAL constellation > of hardware necessary to conduct a comfortable termination > of flight within some ENDURANCE value determined by > the BUILDER . . . not by some 'authority from afar' > who will never ride in the airplane. > > Bob . . . > ________________________________ Message 8 _____________________________________ Time: 10:40:10 AM PST US From: Jeff Luckey Subject: AeroElectric-List: Exploring a Different Way to Wire Avionics Background: Traditionally, all the inter-connections among avionics devices have been m ade via a carefully made custom-built wiring harness.=C2-=C2- Most avionics use DB-9/DB-25 connectors and the custom wire harness approac h comes down to connecting pin #1 on device A to pin #7 on device B and pin #2 of device A to pin #12 on device B, etc, etc.=C2- All this inter-conn ection is done in the harness. I see some downside to this approach: 1. Makes the harness more difficult to fabricate2. Possibly embeds splices in the harness3. Makes trouble shooting more difficult4. Makes subsequent m ods, updates, equipment upgrades more difficult Different Way? Create essentially a fancy junction box that has a bunch of DB-9 & DB-25 co nnectors, one for each device and connects directly to each device.=C2- T hen in this j-box, make all of the device A pin 1 to device B pin 7 inter-c onnections.=C2- This could all be soldered.=C2- It might make pin-shari ng/splicing easier. I'm aware that Advanced Flight Systems has a product that does something li ke this.=C2- I wonder how their inter-connection scheme works because of the multitude of interconnection possibilities with different avionics devi ces.=C2- It seems like all of the combinations/permutations would be diff icult to manage on a circuit board. Some advantages to this approach: 1. Harnesses are much simpler2. All of the "intelligence" is in this j-box/ switch-board which might make mods less labor intensive Some disadvantages:1. Requires more connectors to get the job done2. Adds a nother component (weight?) Any thoughts pro or con are greatly appreciated, -Jeff ________________________________ Message 9 _____________________________________ Time: 10:49:19 AM PST US From: William Daniell Subject: AeroElectric-List: Z16 and three position switch Some of you will remember that I had two switches one for bat and one for ALT on my Z16 because I couldn't obtain a 3 position switch in Colombia where I built my Europa. I always operated the switches BAT only only and Bat ON/ALT ON but never BAT off ALT on. I also reported that every so often the amp reading on my dynon skyview would rise steadily up and off the chart at which point the red X would appear. Subsequently the amp reading would reappear and would fall from 72 down to normal (7-10 depending on the load) and remain steady thereafter. Volts remain stable at 13.8 throughout the rise and fall of the amps. The Skyview is stock using the Dynon Shunt and the Z16 is stock apart from the two switches. I have a Hall Effect sensor with a separate display on the + wire to the battery and this remains within what one would expect 4-5A after start up and then falling to low Amp once the battery has recharged. In the light of this and the absence of exciting sparks and smoke during the last 200 hours I therefore assumed that this must be some sort of Dynon glitch. I had on my list of things to do to check on the Amp reading by an independent instrument. So here is the question: I have now installed the 3 position switch recommended by Bob instead of the two separate switches and the problem has not recurred. Any thoughts? William Daniell LONGPORT +1 786 878 0246 ________________________________ Message 10 ____________________________________ Time: 10:55:42 AM PST US Subject: AeroElectric-List: Re: Physical construction of Z101 engine bus & battery bus From: "user9253" The amount of redundancy desired all depends. Will the aircraft be flying long distances over hostile terrain or water? Will the aircraft be flying IFR or at night? Is the engine dependent on electrical power? Is the pilot willing to carry extra weight to avoid repairs on long cross countries? The important thing is to design an electrical system that does not have unexpected failure modes and that is resistant to pilot error. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=496686#496686 ________________________________ Message 11 ____________________________________ Time: 11:15:45 AM PST US From: James Quinn Subject: Re: AeroElectric-List: Exploring a Different Way to Wire Avionics Approach Fast Stack has been doing this for years - buy a "Hub" and then a purpose build cable for each device. On Mon, Jun 8, 2020 at 12:48 PM Jeff Luckey wrote: > *Background:* > > Traditionally, all the inter-connections among avionics devices have been > made via a carefully made custom-built wiring harness. > > Most avionics use DB-9/DB-25 connectors and the custom wire harness > approach comes down to connecting pin #1 on device A to pin #7 on device B > and pin #2 of device A to pin #12 on device B, etc, etc. All this > inter-connection is done in the harness. > > I see some downside to this approach: > > 1. Makes the harness more difficult to fabricate > 2. Possibly embeds splices in the harness > 3. Makes trouble shooting more difficult > 4. Makes subsequent mods, updates, equipment upgrades more difficult > > > *Different Way?* > > Create essentially a fancy junction box that has a bunch of DB-9 & DB-25 > connectors, one for each device and connects directly to each device. Then > in this j-box, make all of the device A pin 1 to device B pin 7 > inter-connections. This could all be soldered. It might make > pin-sharing/splicing easier. > > I'm aware that Advanced Flight Systems has a product that does something > like this. I wonder how their inter-connection scheme works because of the > multitude of interconnection possibilities with different avionics > devices. It seems like all of the combinations/permutations would be > difficult to manage on a circuit board. > > Some advantages to this approach: > > 1. Harnesses are much simpler > 2. All of the "intelligence" is in this j-box/switch-board which might > make mods less labor intensive > > Some disadvantages: > 1. Requires more connectors to get the job done > 2. Adds another component (weight?) > > > Any thoughts pro or con are greatly appreciated, > > -Jeff > > ________________________________ Message 12 ____________________________________ Time: 11:31:33 AM PST US From: Sebastien Subject: AeroElectric-List: Breaker Anyone need a breaker for their aircraft project? I'm taking a load to the dump. ________________________________ Message 13 ____________________________________ Time: 11:35:00 AM PST US From: Kent or Jackie Ashton Subject: Re: AeroElectric-List: Exploring a Different Way to Wire Avionics Jim Weir wrote an article about a simpler(?) way to connect avionics. Personally, I thought it was about as easy to just develop some skill soldering D-subs and use the standard stuff. There are a few tricks to soldering them but once you have learned them, it is pretty easy. http://www.rstengineering.com/rst/articles/karmic3.pdf One technique is to strip the wire, apply a bit of solder to the wire end, heat up the side of the cup on the D-sub and simultaneously insert the wire end. It is pretty quick with the right iron and solder. -Kent > On Jun 8, 2020, at 1:34 PM, Jeff Luckey wrote: > > Background: > > Traditionally, all the inter-connections among avionics devices have been made via a carefully made custom-built wiring harness. > > Most avionics use DB-9/DB-25 connectors and the custom wire harness approach comes down to connecting pin #1 on device A to pin #7 on device B and pin #2 of device A to pin #12 on device B, etc, etc. All this inter-connection is done in the harness. > > I see some downside to this approach: > > 1. Makes the harness more difficult to fabricate > 2. Possibly embeds splices in the harness > 3. Makes trouble shooting more difficult > 4. Makes subsequent mods, updates, equipment upgrades more difficult > > > Different Way? > > Create essentially a fancy junction box that has a bunch of DB-9 & DB-25 connectors, one for each device and connects directly to each device. Then in this j-box, make all of the device A pin 1 to device B pin 7 inter-connections. This could all be soldered. It might make pin-sharing/splicing easier. > > I'm aware that Advanced Flight Systems has a product that does something like this. I wonder how their inter-connection scheme works because of the multitude of interconnection possibilities with different avionics devices. It seems like all of the combinations/permutations would be difficult to manage on a circuit board. > > Some advantages to this approach: > > 1. Harnesses are much simpler > 2. All of the "intelligence" is in this j-box/switch-board which might make mods less labor intensive > > Some disadvantages: > 1. Requires more connectors to get the job done > 2. Adds another component (weight?) > > > Any thoughts pro or con are greatly appreciated, > > -Jeff > > > > > > > > > ________________________________ Message 14 ____________________________________ Time: 11:41:52 AM PST US From: David Carter Subject: AeroElectric-List: Z101 main alt wiring Bob, Tracing the main alt field circuit from the main bus, I see the following wire sizes: - 16 AWG fusible link - 12 AWG wire to 5A breaker & then to power master switch - 20 AWG wire to regulator - 20 AWG wire to alternator field I don't understand the need for the 12 AWG wire feeding the master, which has only 20 AWG coming out of it to the load. Thanks, David --- David Carter david@carter.net ________________________________ Message 15 ____________________________________ Time: 12:00:39 PM PST US From: Jeff Luckey Subject: Re: AeroElectric-List: Exploring a Different Way to Wire Avionics James, Thanks for the reference to Approach Fast Stack.=C2- That pretty much val idates the concept, doesn't it? On Monday, June 8, 2020, 11:47:19 AM PDT, Kent or Jackie Ashton wrote: net.net> Jim Weir wrote an article about a simpler(?) way to connect avionics.=C2- Personally, I thought it was about as easy to just develop some skill sold ering D-subs and use the standard stuff.=C2- There are a few tricks to so ldering them but once you have learned them, it is pretty easy. http://www.rstengineering.com/rst/articles/karmic3.pdf One technique is to strip the wire, apply a bit of solder to the wire end, heat up the side of the cup on the D-sub and simultaneously insert the wire end.=C2- It is pretty quick with the right iron and solder. -Kent > On Jun 8, 2020, at 1:34 PM, Jeff Luckey wrote: > > Background: > > Traditionally, all the inter-connections among avionics devices have been made via a carefully made custom-built wiring harness.=C2- > > Most avionics use DB-9/DB-25 connectors and the custom wire harness appro ach comes down to connecting pin #1 on device A to pin #7 on device B and p in #2 of device A to pin #12 on device B, etc, etc.=C2- All this inter-co nnection is done in the harness. > > I see some downside to this approach: > > 1. Makes the harness more difficult to fabricate > 2. Possibly embeds splices in the harness > 3. Makes trouble shooting more difficult > 4. Makes subsequent mods, updates, equipment upgrades more difficult > > > Different Way? > > Create essentially a fancy junction box that has a bunch of DB-9 & DB-25 connectors, one for each device and connects directly to each device.=C2- Then in this j-box, make all of the device A pin 1 to device B pin 7 inter -connections.=C2- This could all be soldered.=C2- It might make pin-sha ring/splicing easier. > > I'm aware that Advanced Flight Systems has a product that does something like this.=C2- I wonder how their inter-connection scheme works because o f the multitude of interconnection possibilities with different avionics de vices.=C2- It seems like all of the combinations/permutations would be di fficult to manage on a circuit board. > > Some advantages to this approach: > > 1. Harnesses are much simpler > 2. All of the "intelligence" is in this j-box/switch-board which might ma ke mods less labor intensive > > Some disadvantages: > 1. Requires more connectors to get the job done > 2. Adds another component (weight?) > > > Any thoughts pro or con are greatly appreciated, > > -Jeff > > > > > > > > > - S - WIKI - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ________________________________ Message 16 ____________________________________ Time: 12:06:01 PM PST US From: Alec Myers Subject: Re: AeroElectric-List: Exploring a Different Way to Wire Avionics Not just more connectors. Theres a huge bunch of redundancy to most of the pins on the back of a GPS or VOR receiver or transceiver; of about 300 pins on the back of my IFD540 maybe 50 are connected; which 50 depends on what else is in the system (CDI/OBS or HSI? Autopilot? Second GPS slaved to first?) so either your standard cables to your patch box are immensely thick and bulky and expensive, or you have to make up custom cables to the patch box. In which case, you might as well make up a custom harness. Honestly, its not difficult or complicated to make a harness; the complicated bit is working out what pin should connect to what pin, and you have to do that anyway. On Jun 8, 2020, at 2:10 PM, James Quinn wrote: Approach Fast Stack has been doing this for years - buy a "Hub" and then a purpose build cable for each device. On Mon, Jun 8, 2020 at 12:48 PM Jeff Luckey wrote: Background: Traditionally, all the inter-connections among avionics devices have been made via a carefully made custom-built wiring harness. Most avionics use DB-9/DB-25 connectors and the custom wire harness approach comes down to connecting pin #1 on device A to pin #7 on device B and pin #2 of device A to pin #12 on device B, etc, etc. All this inter-connection is done in the harness. I see some downside to this approach: 1. Makes the harness more difficult to fabricate 2. Possibly embeds splices in the harness 3. Makes trouble shooting more difficult 4. Makes subsequent mods, updates, equipment upgrades more difficult Different Way? Create essentially a fancy junction box that has a bunch of DB-9 & DB-25 connectors, one for each device and connects directly to each device. Then in this j-box, make all of the device A pin 1 to device B pin 7 inter-connections. This could all be soldered. It might make pin-sharing/splicing easier. I'm aware that Advanced Flight Systems has a product that does something like this. I wonder how their inter-connection scheme works because of the multitude of interconnection possibilities with different avionics devices. It seems like all of the combinations/permutations would be difficult to manage on a circuit board. Some advantages to this approach: 1. Harnesses are much simpler 2. All of the "intelligence" is in this j-box/switch-board which might make mods less labor intensive Some disadvantages: 1. Requires more connectors to get the job done 2. Adds another component (weight?) Any thoughts pro or con are greatly appreciated, -Jeff ________________________________ Message 17 ____________________________________ Time: 12:15:13 PM PST US From: Jeff Luckey Subject: Re: AeroElectric-List: Breaker LoL! Can I use that to turn-on my nav lights? ... On Monday, June 8, 2020, 11:54:06 AM PDT, Sebastien wrote: Anyone need a breaker for their aircraft project? I'm taking a load to the dump. ________________________________ Message 18 ____________________________________ Time: 12:19:02 PM PST US From: Charlie England Subject: Re: AeroElectric-List: Exploring a Different Way to Wire Avionics I, too, have wondered how they accommodate various 'random ' avionics. It wouldn't be too surprising if they're doing the 'pin relocation' task for you in the custom interconnect cables for which you're paying big bucks. Charlie On Mon, Jun 8, 2020 at 2:07 PM Jeff Luckey wrote: > James, > > Thanks for the reference to Approach Fast Stack. That pretty much > validates the concept, doesn't it? > > On Monday, June 8, 2020, 11:47:19 AM PDT, Kent or Jackie Ashton < > kjashton@vnet.net> wrote: > > > kjashton@vnet.net> > > Jim Weir wrote an article about a simpler(?) way to connect avionics. > Personally, I thought it was about as easy to just develop some skill > soldering D-subs and use the standard stuff. There are a few tricks to > soldering them but once you have learned them, it is pretty easy. > http://www.rstengineering.com/rst/articles/karmic3.pdf > > One technique is to strip the wire, apply a bit of solder to the wire end, > heat up the side of the cup on the D-sub and simultaneously insert the wire > end. It is pretty quick with the right iron and solder. > -Kent > > > On Jun 8, 2020, at 1:34 PM, Jeff Luckey wrote: > > > > Background: > > > > Traditionally, all the inter-connections among avionics devices have > been made via a carefully made custom-built wiring harness. > > > > Most avionics use DB-9/DB-25 connectors and the custom wire harness > approach comes down to connecting pin #1 on device A to pin #7 on device B > and pin #2 of device A to pin #12 on device B, etc, etc. All this > inter-connection is done in the harness. > > > > I see some downside to this approach: > > > > 1. Makes the harness more difficult to fabricate > > 2. Possibly embeds splices in the harness > > 3. Makes trouble shooting more difficult > > 4. Makes subsequent mods, updates, equipment upgrades more difficult > > > > > > Different Way? > > > > Create essentially a fancy junction box that has a bunch of DB-9 & DB-25 > connectors, one for each device and connects directly to each device. Then > in this j-box, make all of the device A pin 1 to device B pin 7 > inter-connections. This could all be soldered. It might make > pin-sharing/splicing easier. > > > > I'm aware that Advanced Flight Systems has a product that does something > like this. I wonder how their inter-connection scheme works because of the > multitude of interconnection possibilities with different avionics > devices. It seems like all of the combinations/permutations would be > difficult to manage on a circuit board. > > > > Some advantages to this approach: > > > > 1. Harnesses are much simpler > > 2. All of the "intelligence" is in this j-box/switch-board which might > make mods less labor intensive > > > > Some disadvantages: > > 1. Requires more connectors to get the job done > > 2. Adds another component (weight?) > > > > > > Any thoughts pro or con are greatly appreciated, > > > > -Jeff > > > > > > > > > > > > > > > > > > > > http://www.m==================== > http://forums.matronics.com > ===================== > http://wiki.matron======================= > > > ________________________________ Message 19 ____________________________________ Time: 12:26:49 PM PST US From: Charlie England Subject: Re: AeroElectric-List: Z101 main alt wiring On Mon, Jun 8, 2020 at 1:47 PM David Carter wrote: > Bob, > > Tracing the main alt field circuit from the main bus, I see the following > wire sizes: > - 16 AWG fusible link > - 12 AWG wire to 5A breaker & then to power master switch > - 20 AWG wire to regulator > - 20 AWG wire to alternator field > > I don't understand the need for the 12 AWG wire feeding the master, which > has only 20 AWG coming out of it to the load. > > Thanks, > David > > > --- > David Carter > david@carter.net > Reasonable question; might have been driven by 'off-the-shelf' fusible link size availability. 22awg (minimum reasonable size to work with) link (sleeved with silicone tubing) to 18awg would get the job done. 20awg after the breaker because the breaker protects it. I've tested the silicone tubing trick on 22awg with a direct short on a 12v tractor battery. The wire vaporizes, leaving a smoky interior lining on the clear silicone tubing, but the tubing contained the 'event'. Charlie ________________________________ Message 20 ____________________________________ Time: 01:08:12 PM PST US From: Sebastien Subject: Re: AeroElectric-List: Breaker 225 Amp so it should be good. Aeroelectric said my picture was too big so here's a smaller version. On Mon, Jun 8, 2020 at 12:20 PM Jeff Luckey wrote: > LoL! > > Can I use that to turn-on my nav lights? ... > > On Monday, June 8, 2020, 11:54:06 AM PDT, Sebastien > wrote: > > > Anyone need a breaker for their aircraft project? I'm taking a load to the > dump. > > ________________________________ Message 21 ____________________________________ Time: 03:20:57 PM PST US From: Charlie England Subject: Re: AeroElectric-List: Breaker Should be perfect for a *real* all electric airplane on a budget.... Seriously, did you try listing stuff like that on ebay? I've bought some 3 phase stuff there for my house & shop (yes, I've got Delta to the house), and I know some machine shop guys who watch auction sites for stuff like that. Charlie On Mon, Jun 8, 2020 at 3:19 PM Sebastien wrote: > 225 Amp so it should be good. > > Aeroelectric said my picture was too big so here's a smaller version. > > On Mon, Jun 8, 2020 at 12:20 PM Jeff Luckey wrote: > >> LoL! >> >> Can I use that to turn-on my nav lights? ... >> >> On Monday, June 8, 2020, 11:54:06 AM PDT, Sebastien >> wrote: >> >> >> Anyone need a breaker for their aircraft project? I'm taking a load to >> the dump. >> >> >> >> >> >> ________________________________ Message 22 ____________________________________ Time: 03:42:42 PM PST US From: Charlie England Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus Hi Ken, I'll take a swing at it, but would suggest that it's not quite the right question. I get your point, but the answer 'depends'. If using electronic fuel injection, the current demands mean that a single PC680 style battery (in 'new' condition) will only buy you about 30-40 minutes of flight time after alternator failure. A 2nd PC680 only adds another 30-40 minutes. On an engine that allows two alts, either of which can keep the engine running and the panel lit, a typical alt (ex: 55A Denso) is lighter than a 2nd battery, not much more expensive (actually much cheaper than an actual Odyssey branded PC680), will keep the engine running to fuel exhaustion, and has the additional benefit of allowing a return flight (in some range-dependent situations) without the need of maintenance while on the road. Not something I would ever consider after an alt failure with only a 2nd bat for backup. Add to the mix, the fact that while a 2nd alt is pretty much an install&forget item (just a startup check each flight similar to a mag check), any battery is a constantly degrading item that requires regular capacity testing to ensure that it has enough remaining capacity to give expected duration if called upon. Now, with carb or mech fuel injection in a VFR environment, current demands might (likely will) be low enough that a single bat & single alt back up each other. In *my* opinion, that's where Bob's statement makes sense, and where your question, as framed, doesn't need asking. So, I think you really have to define both the mission *and the hardware* to pick an architecture. FWIW, Charlie On Mon, Jun 8, 2020 at 11:15 AM Ken Ryan wrote: > Bob, you said: > > "If you have TWO properly maintained batteries, > in all likelihood, you'll be carrying around > $twice$ the hardware with virtually no value > added to the ship's overall reliability." > > Help me understand why the following statement is not correct: > > If you have TWO properly maintained alternators, > plus a battery (sized for minimum endurance requirements) > in all likelihood, you'll be carrying around > $twice$ the hardware with virtually no value > added to the ship's overall reliability. > > Ken > > On Sun, Jun 7, 2020 at 6:56 PM Robert L. Nuckolls, III < > nuckolls.bob@aeroelectric.com> wrote: > >> At 05:26 PM 6/7/2020, you wrote: >> >> I am not speaking to any engine manufacturers recommendation (although t he >> Honda Viking manufacturer does recommend two batteries. I just thought >> I was applying logic -- if dual alternator=C3=82 + battery (triple power >> source) >> is desirable for electrically=C3=82 dependent engines, wouldn't that rea soning >> imply that if the second alternator is not practical, a second battery >> could be used as the third power source? I could ask you a similar >> question: >> Are not two independent power sources (battery and alternator) sufficien t >> to meet the needs of the electrically=C3=82 dependent engine. Obviously you >> saw value in adding the second alternator. Why no value in adding the >> second battery? >> >> >> Excellent question. >> >> It's a problem in energy budgets combined with >> efforts to assure continued airworthiness. >> >> The airplane cannot do without a battery if >> you're going to have a starter. Depending on >> your planned mission profiles, you will want >> to size the battery (1) for cranking then >> (2) minimum endurance in alternator-out modes. >> >> This study gave impetus for the creation of >> the endurance bus . . . a fast and predictable >> way to economically tap known quantity of energy >> stored in the battery's chemistry. >> >> Z13/8 was a small but significant amplification >> of that idea . . . the second alternator's endurance >> had no practical limits. Hence, energy on the chemistry >> just might be held completely in reserve for >> descent and approach to landing. >> >> Z13/20 (and the aux alternator option on >> Z101) expanded the Z13/8 endurance opportunity >> by a factor of 2.5 or better. >> >> Okay, suppose the drive pad isn't available. >> We are still charged with identifying and the >> delivering to energy required to comfortably >> terminate a worst-case mission. >> >> This means that as a part of routine maintenance >> the ship's chemistry needs to be monitored for >> capability. We could certainly store that energy >> on TWO devices but to what advantage? If we're laboring >> under the notion that a battery can suddenly become >> unavailable during one tank of gas, then we have >> to assume that EITHER battery can roll over and >> die . . . okay, how would that failure be >> annunciated . . . how would remaining energy be >> managed . . . ? >> >> I think that's the scenario anticipated by the >> folks that crafted that battery manager with a >> full-wave rectifier that -anded- two, completely >> isolated batteries together. Assume the alternator >> has quit and some time later one battery >> craps out. How does the pilot become aware of the >> problem and what kind of energy juggling issues >> are presented when the available energy drops >> to half? This assuming he really knows that the >> two batteries were performing equally and has >> recently quantified their condition, he now >> has to come up with a new "plan C?" and perhaps >> declare an emergency. >> >> This scenario first assumes TWO critical failures >> during the consumption of one tank of fuel . . . >> about 3-4 hour window. Part 23 certs don't >> get concerned with dual failures at all. >> Part 25 and heavier will wade into the reliability >> quagmire with mountains of computer generated probability >> studies that get 'worked' on until somebody >> finally sprinkles the holy water and off they >> go. >> >> Ask Capt. Sullivan what he thinks about >> reliability studies . . . >> >> https://www.youtube.com/watch?v=HKJ1lIh2Cgk >> >> So we're left to our own devices which in reality >> are not so bad. >> >> The short answer is: A diligently maintained >> battery is the most reliable source of energy >> on the airplane. Replacing it when ability >> to store energy drops below some benchmark >> (generally 75 to 80% of new) means that it >> always cranks the engine and will provide a >> quantified option for dealing with alternator >> failure. Two batteries just doubles your >> preventative maintenance labor. Further, >> you need to decide if plan-b can reliably >> depend on the sum total of energy in two >> batteries . . . or will they be sized to >> independently step up to the task? The >> second option calls for 2X the battery >> weight and volume; the first option complicates >> calculations and switching operations for >> carrying out a plan-b that shouldn't ever >> happen. BOTH options still demand good >> preventative maintenance. >> >> Just as you KNOW fuel aboard when you launch, >> you also need to know Watt-Hours aboard >> no matter how many batteries you're carrying. >> >> If you have TWO properly maintained batteries, >> in all likelihood, you'll be carrying around >> $twice$ the hardware with virtually no value >> added to the ship's overall reliability. >> >> Bob . . . >> > ________________________________ Message 23 ____________________________________ Time: 04:09:27 PM PST US From: Sebastien Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus Or I'll tackle it a different way: What are the sudden failure rates of batteries and alternators. I've lost a couple alternators in flight, I've never heard of a good battery failing in flight. On Mon, Jun 8, 2020, 15:49 Charlie England wrote: > Hi Ken, > > I'll take a swing at it, but would suggest that it's not quite the right > question. > > I get your point, but the answer 'depends'. If using electronic fuel > injection, the current demands mean that a single PC680 style battery (in > 'new' condition) will only buy you about 30-40 minutes of flight time > after alternator failure. A 2nd PC680 only adds another 30-40 minutes. On > an engine that allows two alts, either of which can keep the engine runni ng > and the panel lit, a typical alt (ex: 55A Denso) is lighter than a 2nd > battery, not much more expensive (actually much cheaper than an actual > Odyssey branded PC680), will keep the engine running to fuel exhaustion, > and has the additional benefit of allowing a return flight (in some > range-dependent situations) without the need of maintenance while on the > road. Not something I would ever consider after an alt failure with only a > 2nd bat for backup. Add to the mix, the fact that while a 2nd alt is pret ty > much an install&forget item (just a startup check each flight similar to a > mag check), any battery is a constantly degrading item that requires > regular capacity testing to ensure that it has enough remaining capacity to > give expected duration if called upon. > > Now, with carb or mech fuel injection in a VFR environment, current > demands might (likely will) be low enough that a single bat & single alt > back up each other. In *my* opinion, that's where Bob's statement makes > sense, and where your question, as framed, doesn't need asking. > > So, I think you really have to define both the mission *and the hardware* > to pick an architecture. > > FWIW, > > Charlie > > On Mon, Jun 8, 2020 at 11:15 AM Ken Ryan wrote: > >> Bob, you said: >> >> "If you have TWO properly maintained batteries, >> in all likelihood, you'll be carrying around >> $twice$ the hardware with virtually no value >> added to the ship's overall reliability." >> >> Help me understand why the following statement is not correct: >> >> If you have TWO properly maintained alternators, >> plus a battery (sized for minimum endurance requirements) >> in all likelihood, you'll be carrying around >> $twice$ the hardware with virtually no value >> added to the ship's overall reliability. >> >> Ken >> >> On Sun, Jun 7, 2020 at 6:56 PM Robert L. Nuckolls, III < >> nuckolls.bob@aeroelectric.com> wrote: >> >>> At 05:26 PM 6/7/2020, you wrote: >>> >>> I am not speaking to any engine manufacturers recommendation (although >>> the >>> Honda Viking manufacturer does recommend two batteries. I just thought >>> I was applying logic -- if dual alternator=C3=82 + battery (triple powe r >>> source) >>> is desirable for electrically=C3=82 dependent engines, wouldn't that re asoning >>> imply that if the second alternator is not practical, a second battery >>> could be used as the third power source? I could ask you a similar >>> question: >>> Are not two independent power sources (battery and alternator) sufficie nt >>> to meet the needs of the electrically=C3=82 dependent engine. Obviously you >>> saw value in adding the second alternator. Why no value in adding the >>> second battery? >>> >>> >>> Excellent question. >>> >>> It's a problem in energy budgets combined with >>> efforts to assure continued airworthiness. >>> >>> The airplane cannot do without a battery if >>> you're going to have a starter. Depending on >>> your planned mission profiles, you will want >>> to size the battery (1) for cranking then >>> (2) minimum endurance in alternator-out modes. >>> >>> This study gave impetus for the creation of >>> the endurance bus . . . a fast and predictable >>> way to economically tap known quantity of energy >>> stored in the battery's chemistry. >>> >>> Z13/8 was a small but significant amplification >>> of that idea . . . the second alternator's endurance >>> had no practical limits. Hence, energy on the chemistry >>> just might be held completely in reserve for >>> descent and approach to landing. >>> >>> Z13/20 (and the aux alternator option on >>> Z101) expanded the Z13/8 endurance opportunity >>> by a factor of 2.5 or better. >>> >>> Okay, suppose the drive pad isn't available. >>> We are still charged with identifying and the >>> delivering to energy required to comfortably >>> terminate a worst-case mission. >>> >>> This means that as a part of routine maintenance >>> the ship's chemistry needs to be monitored for >>> capability. We could certainly store that energy >>> on TWO devices but to what advantage? If we're laboring >>> under the notion that a battery can suddenly become >>> unavailable during one tank of gas, then we have >>> to assume that EITHER battery can roll over and >>> die . . . okay, how would that failure be >>> annunciated . . . how would remaining energy be >>> managed . . . ? >>> >>> I think that's the scenario anticipated by the >>> folks that crafted that battery manager with a >>> full-wave rectifier that -anded- two, completely >>> isolated batteries together. Assume the alternator >>> has quit and some time later one battery >>> craps out. How does the pilot become aware of the >>> problem and what kind of energy juggling issues >>> are presented when the available energy drops >>> to half? This assuming he really knows that the >>> two batteries were performing equally and has >>> recently quantified their condition, he now >>> has to come up with a new "plan C?" and perhaps >>> declare an emergency. >>> >>> This scenario first assumes TWO critical failures >>> during the consumption of one tank of fuel . . . >>> about 3-4 hour window. Part 23 certs don't >>> get concerned with dual failures at all. >>> Part 25 and heavier will wade into the reliability >>> quagmire with mountains of computer generated probability >>> studies that get 'worked' on until somebody >>> finally sprinkles the holy water and off they >>> go. >>> >>> Ask Capt. Sullivan what he thinks about >>> reliability studies . . . >>> >>> https://www.youtube.com/watch?v=HKJ1lIh2Cgk >>> >>> So we're left to our own devices which in reality >>> are not so bad. >>> >>> The short answer is: A diligently maintained >>> battery is the most reliable source of energy >>> on the airplane. Replacing it when ability >>> to store energy drops below some benchmark >>> (generally 75 to 80% of new) means that it >>> always cranks the engine and will provide a >>> quantified option for dealing with alternator >>> failure. Two batteries just doubles your >>> preventative maintenance labor. Further, >>> you need to decide if plan-b can reliably >>> depend on the sum total of energy in two >>> batteries . . . or will they be sized to >>> independently step up to the task? The >>> second option calls for 2X the battery >>> weight and volume; the first option complicates >>> calculations and switching operations for >>> carrying out a plan-b that shouldn't ever >>> happen. BOTH options still demand good >>> preventative maintenance. >>> >>> Just as you KNOW fuel aboard when you launch, >>> you also need to know Watt-Hours aboard >>> no matter how many batteries you're carrying. >>> >>> If you have TWO properly maintained batteries, >>> in all likelihood, you'll be carrying around >>> $twice$ the hardware with virtually no value >>> added to the ship's overall reliability. >>> >>> Bob . . . >>> >> ________________________________ Message 24 ____________________________________ Time: 04:09:55 PM PST US From: Sebastien Subject: Re: AeroElectric-List: Breaker Dad says he's been listing it on Craigslist for years and never got a bite. We got $73 at the recyclers for scrap aluminium and a couple motors and the dump run cost $17 so not a complete loss. On Mon, Jun 8, 2020, 15:28 Charlie England wrote: > Should be perfect for a *real* all electric airplane on a budget.... > > Seriously, did you try listing stuff like that on ebay? I've bought some 3 > phase stuff there for my house & shop (yes, I've got Delta to the house), > and I know some machine shop guys who watch auction sites for stuff like > that. > > Charlie > > On Mon, Jun 8, 2020 at 3:19 PM Sebastien wrote: > >> 225 Amp so it should be good. >> >> Aeroelectric said my picture was too big so here's a smaller version. >> >> On Mon, Jun 8, 2020 at 12:20 PM Jeff Luckey wrote: >> >>> LoL! >>> >>> Can I use that to turn-on my nav lights? ... >>> >>> On Monday, June 8, 2020, 11:54:06 AM PDT, Sebastien >>> wrote: >>> >>> >>> Anyone need a breaker for their aircraft project? I'm taking a load to >>> the dump. >>> >>> >>> >>> >>> >>> ________________________________ Message 25 ____________________________________ Time: 04:22:38 PM PST US From: Ken Ryan Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus Thanks Charlie, I am convinced that 2 alternators + 1 battery is superior to 1 alternator + 2 batteries. I am less convinced that if two alternators are not possible, a second battery adds virtually no value to the ship's overall reliability. Bob did make a pretty good argument, but it is founded on the assumption that the battery, when properly maintained, is utterly reliable. I have two problems with that assumption: 1) we know from Joe's experience that batteries can fail and 2) even with the best of intentions, maintenance (including battery maintenance) is not always perfect. To contend that having a fresh battery available at the flip of a switch adds no reliability to an electrically dependent aircraft still seems like a bit of a stretch to me. Ken On Mon, Jun 8, 2020 at 2:49 PM Charlie England wrote : > Hi Ken, > > I'll take a swing at it, but would suggest that it's not quite the right > question. > > I get your point, but the answer 'depends'. If using electronic fuel > injection, the current demands mean that a single PC680 style battery (in > 'new' condition) will only buy you about 30-40 minutes of flight time > after alternator failure. A 2nd PC680 only adds another 30-40 minutes. On > an engine that allows two alts, either of which can keep the engine runni ng > and the panel lit, a typical alt (ex: 55A Denso) is lighter than a 2nd > battery, not much more expensive (actually much cheaper than an actual > Odyssey branded PC680), will keep the engine running to fuel exhaustion, > and has the additional benefit of allowing a return flight (in some > range-dependent situations) without the need of maintenance while on the > road. Not something I would ever consider after an alt failure with only a > 2nd bat for backup. Add to the mix, the fact that while a 2nd alt is pret ty > much an install&forget item (just a startup check each flight similar to a > mag check), any battery is a constantly degrading item that requires > regular capacity testing to ensure that it has enough remaining capacity to > give expected duration if called upon. > > Now, with carb or mech fuel injection in a VFR environment, current > demands might (likely will) be low enough that a single bat & single alt > back up each other. In *my* opinion, that's where Bob's statement makes > sense, and where your question, as framed, doesn't need asking. > > So, I think you really have to define both the mission *and the hardware* > to pick an architecture. > > FWIW, > > Charlie > > On Mon, Jun 8, 2020 at 11:15 AM Ken Ryan wrote: > >> Bob, you said: >> >> "If you have TWO properly maintained batteries, >> in all likelihood, you'll be carrying around >> $twice$ the hardware with virtually no value >> added to the ship's overall reliability." >> >> Help me understand why the following statement is not correct: >> >> If you have TWO properly maintained alternators, >> plus a battery (sized for minimum endurance requirements) >> in all likelihood, you'll be carrying around >> $twice$ the hardware with virtually no value >> added to the ship's overall reliability. >> >> Ken >> >> On Sun, Jun 7, 2020 at 6:56 PM Robert L. Nuckolls, III < >> nuckolls.bob@aeroelectric.com> wrote: >> >>> At 05:26 PM 6/7/2020, you wrote: >>> >>> I am not speaking to any engine manufacturers recommendation (although >>> the >>> Honda Viking manufacturer does recommend two batteries. I just thought >>> I was applying logic -- if dual alternator=C3=82 + battery (triple powe r >>> source) >>> is desirable for electrically=C3=82 dependent engines, wouldn't that re asoning >>> imply that if the second alternator is not practical, a second battery >>> could be used as the third power source? I could ask you a similar >>> question: >>> Are not two independent power sources (battery and alternator) sufficie nt >>> to meet the needs of the electrically=C3=82 dependent engine. Obviously you >>> saw value in adding the second alternator. Why no value in adding the >>> second battery? >>> >>> >>> Excellent question. >>> >>> It's a problem in energy budgets combined with >>> efforts to assure continued airworthiness. >>> >>> The airplane cannot do without a battery if >>> you're going to have a starter. Depending on >>> your planned mission profiles, you will want >>> to size the battery (1) for cranking then >>> (2) minimum endurance in alternator-out modes. >>> >>> This study gave impetus for the creation of >>> the endurance bus . . . a fast and predictable >>> way to economically tap known quantity of energy >>> stored in the battery's chemistry. >>> >>> Z13/8 was a small but significant amplification >>> of that idea . . . the second alternator's endurance >>> had no practical limits. Hence, energy on the chemistry >>> just might be held completely in reserve for >>> descent and approach to landing. >>> >>> Z13/20 (and the aux alternator option on >>> Z101) expanded the Z13/8 endurance opportunity >>> by a factor of 2.5 or better. >>> >>> Okay, suppose the drive pad isn't available. >>> We are still charged with identifying and the >>> delivering to energy required to comfortably >>> terminate a worst-case mission. >>> >>> This means that as a part of routine maintenance >>> the ship's chemistry needs to be monitored for >>> capability. We could certainly store that energy >>> on TWO devices but to what advantage? If we're laboring >>> under the notion that a battery can suddenly become >>> unavailable during one tank of gas, then we have >>> to assume that EITHER battery can roll over and >>> die . . . okay, how would that failure be >>> annunciated . . . how would remaining energy be >>> managed . . . ? >>> >>> I think that's the scenario anticipated by the >>> folks that crafted that battery manager with a >>> full-wave rectifier that -anded- two, completely >>> isolated batteries together. Assume the alternator >>> has quit and some time later one battery >>> craps out. How does the pilot become aware of the >>> problem and what kind of energy juggling issues >>> are presented when the available energy drops >>> to half? This assuming he really knows that the >>> two batteries were performing equally and has >>> recently quantified their condition, he now >>> has to come up with a new "plan C?" and perhaps >>> declare an emergency. >>> >>> This scenario first assumes TWO critical failures >>> during the consumption of one tank of fuel . . . >>> about 3-4 hour window. Part 23 certs don't >>> get concerned with dual failures at all. >>> Part 25 and heavier will wade into the reliability >>> quagmire with mountains of computer generated probability >>> studies that get 'worked' on until somebody >>> finally sprinkles the holy water and off they >>> go. >>> >>> Ask Capt. Sullivan what he thinks about >>> reliability studies . . . >>> >>> https://www.youtube.com/watch?v=HKJ1lIh2Cgk >>> >>> So we're left to our own devices which in reality >>> are not so bad. >>> >>> The short answer is: A diligently maintained >>> battery is the most reliable source of energy >>> on the airplane. Replacing it when ability >>> to store energy drops below some benchmark >>> (generally 75 to 80% of new) means that it >>> always cranks the engine and will provide a >>> quantified option for dealing with alternator >>> failure. Two batteries just doubles your >>> preventative maintenance labor. Further, >>> you need to decide if plan-b can reliably >>> depend on the sum total of energy in two >>> batteries . . . or will they be sized to >>> independently step up to the task? The >>> second option calls for 2X the battery >>> weight and volume; the first option complicates >>> calculations and switching operations for >>> carrying out a plan-b that shouldn't ever >>> happen. BOTH options still demand good >>> preventative maintenance. >>> >>> Just as you KNOW fuel aboard when you launch, >>> you also need to know Watt-Hours aboard >>> no matter how many batteries you're carrying. >>> >>> If you have TWO properly maintained batteries, >>> in all likelihood, you'll be carrying around >>> $twice$ the hardware with virtually no value >>> added to the ship's overall reliability. >>> >>> Bob . . . >>> >> ________________________________ Message 26 ____________________________________ Time: 04:31:47 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus >If you don=99t have a second alternator, you >should have a small backup battery. Sizing would >depend on your typical/ maximum distance between >airports. Current draw of the pump, ECU, >injectors and coils would be around 12 to 14 >amps. A 12 amp/hour battery should give you a >solid 30-40 minutes of flight time, just running >the engine electrics. An 18 amp/hour one, around >1 hour. We want to be able to sustain at least 10 volts to the electrics. > >We=99ve found the most reliable, simple and >light way to get backup battery power to the >engine electrics is a single 12 to 14 gauge wire >running from the backup battery, through a 30 >amp ATO fuse, to a heavy duty switch, to an >emergency buss where all the engine electrics >can receive power. Simply charge the backup >battery every 30 days and load test annually. >If you have the recommended check engine light >fitted, it will warn you any time the battery >voltage falls below 12.5V. You can monitor battery voltage in Gauge 3 mode. A statement that is understandable and predictable. EVERY supplier of electrically dependent aircraft accessories has a vested interest in NOT having their product figure into the script for your bad day in the cockpit. Their "most reliable finding" focuses on their product . . . and while certainly critical for continued flight, it's not the only critical electro-whizzie on the airplane. All creative assemblages stand on the 3-legged stool of energy-management, properties-of- materials and refinement-of-process. It doesn't matter if you're cooking breakfast or building a space shuttle. I think I've suggested before that installation manuals for such products should call for, "Energy supplied by a robust, failure tolerant and competently maintained electrical system." To be sure . . . many of our brothers don't have strong interests or appreciation for elegant solutions and prefer the cookie-cutter approach. Nothing overtly wrong with that but it can generate systems with high costs of ownership, unnecessary weight and complexity. Complexity adds risk for lack of understanding and mis-application of features originally intended to keep a tense day in the cockpit from getting worst. We don't do gps receivers here . . . or engines, or auto-pilots. We do system integration with a goal of achieving the simplest, failure tolerant supply and distribution systems. A natural fallout of those endeavors is lower cost of ownership and weight. Getting back to the subject engine, what's the 'advantage' of carrying a second battery that may never be used as opposed to carrying one battery sized and maintained to meet what ever endurance goals are sought for the whole airplane? Bob . . . ________________________________ Message 27 ____________________________________ Time: 04:56:49 PM PST US Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus From: Charlie England For me, it's not so much that a 'good battery will *fail* in flight', but that the battery's capacity is continuously degrading, whether it's used or not, and that introduces a 2nd variable in the backup plan. It's not obvious, but a tired battery may well start an engine with gusto, but if called on to supply a continuous 14A (just to the engine), it might go dead in 10-15 minutes. My personal comfort zone bends toward an alternator, if I'm going to install a backup. Again, this is driven by the relatively high current demand of the electronic injection system in my project a/c. If I only had to support an electronic ignition (1-2 amps) and a radio, I'd be a lot more comfortable depending on the battery as backup. In fact, my current RV6 with mechanical injection and one Lightspeed has one alternator & one battery. I'm a VFR pilot and not dependent on electron delivery to keep the engine running or keep the dirty side down. Charlie On 6/8/2020 6:05 PM, Sebastien wrote: > Or I'll tackle it a different way: > > What are the sudden failure rates of batteries and alternators. I've > lost a couple alternators in flight, I've never heard of a good > battery failing in flight. > > On Mon, Jun 8, 2020, 15:49 Charlie England > wrote: > > Hi Ken, > > I'll take a swing at it, but would suggest that it's not quite the > right question. > > I get your point, but the answer 'depends'. If using electronic > fuel injection, the current demands mean that a single PC680 style > battery (in 'new' condition) will only buy you about 30-40 > minutes of flight time after alternator failure. A 2nd PC680 only > adds another 30-40 minutes. On an engine that allows two alts, > either of which can keep the engine running and the panel lit, a > typical alt (ex: 55A Denso) is lighter than a 2nd battery, not > much more expensive (actually much cheaper than an actual Odyssey > branded PC680), will keep the engine running to fuel exhaustion, > and has the additionalbenefit of allowing a return flight (in > some range-dependent situations) without the need of maintenance > while on the road. Not something I would ever consider after an > alt failure with only a 2nd bat for backup. Add to the mix, the > fact that while a 2nd alt is pretty much an install&forget item > (just a startup check each flight similar to a mag check), any > battery is a constantly degrading item that requires regular > capacity testing to ensure that it has enough remaining capacity > to give expected duration if called upon. > > Now, with carb or mech fuel injection in a VFR environment, > current demands might (likely will) be low enough that a single > bat & single alt back up each other. In *my* opinion, that's where > Bob's statement makes sense, and where your question, as framed, > doesn't need asking. > > So, I think you really have to define both the mission *and the > hardware* to pick an architecture. > > FWIW, > > Charlie > > On Mon, Jun 8, 2020 at 11:15 AM Ken Ryan > wrote: > > Bob, you said: > > "If you have TWO properly maintained batteries, > in all likelihood, you'll be carrying around > $twice$ the hardware with virtually no value > added to the ship's overall reliability." > > Help me understand why the following statement is not correct: > > If you have TWO properly maintained alternators, > plus a battery (sized for minimum endurance requirements) > in all likelihood, you'll be carrying around > $twice$ the hardware with virtually no value > added to the ship's overall reliability. > > Ken > > On Sun, Jun 7, 2020 at 6:56 PM Robert L. Nuckolls, III > > wrote: > > At 05:26 PM 6/7/2020, you wrote: >> I am not speaking to any engine manufacturers >> recommendation (although the >> Honda Viking manufacturer does recommend two batteries. I >> just thought >> I was applying logic -- if dual alternator + battery >> (triple power source) >> is desirable for electrically dependent engines, >> wouldn't that reasoning >> imply that if the second alternator is not practical, a >> second battery >> could be used as the third power source? I could ask you >> a similar question: >> Are not two independent power sources (battery and >> alternator) sufficient >> to meet the needs of the electrically dependent engine. >> Obviously you >> saw value in adding the second alternator. Why no value >> in adding the second battery? > > Excellent question. > > It's a problem in energy budgets combined with > efforts to assure continued airworthiness. > > The airplane cannot do without a battery if > you're going to have a starter. Depending on > your planned mission profiles, you will want > to size the battery (1) for cranking then > (2) minimum endurance in alternator-out modes. > > This study gave impetus for the creation of > the endurance bus . . . a fast and predictable > way to economically tap known quantity of energy > stored in the battery's chemistry. > > Z13/8 was a small but significant amplification > of that idea . . . the second alternator's endurance > had no practical limits. Hence, energy on the chemistry > just might be held completely in reserve for > descent and approach to landing. > > Z13/20 (and the aux alternator option on > Z101) expanded the Z13/8 endurance opportunity > by a factor of 2.5 or better. > > Okay, suppose the drive pad isn't available. > We are still charged with identifying and the > delivering to energy required to comfortably > terminate a worst-case mission. > > This means that as a part of routine maintenance > the ship's chemistry needs to be monitored for > capability. We could certainly store that energy > on TWO devices but to what advantage? If we're laboring > under the notion that a battery can suddenly become > unavailable during one tank of gas, then we have > to assume that EITHER battery can roll over and > die . . . okay, how would that failure be > annunciated . . . how would remaining energy be > managed . . . ? > > I think that's the scenario anticipated by the > folks that crafted that battery manager with a > full-wave rectifier that -anded- two, completely > isolated batteries together. Assume the alternator > has quit and some time later one battery > craps out. How does the pilot become aware of the > problem and what kind of energy juggling issues > are presented when the available energy drops > to half? This assuming he really knows that the > two batteries were performing equally and has > recently quantified their condition, he now > has to come up with a new "plan C?" and perhaps > declare an emergency. > > This scenario first assumes TWO critical failures > during the consumption of one tank of fuel . . . > about 3-4 hour window. Part 23 certs don't > get concerned with dual failures at all. > Part 25 and heavier will wade into the reliability > quagmire with mountains of computer generated probability > studies that get 'worked' on until somebody > finally sprinkles the holy water and off they > go. > > Ask Capt. Sullivan what he thinks about > reliability studies . . . > > https://www.youtube.com/watch?v=HKJ1lIh2Cgk > > > So we're left to our own devices which in reality > are not so bad. > > The short answer is: A diligently maintained > battery is the most reliable source of energy > on the airplane. Replacing it when ability > to store energy drops below some benchmark > (generally 75 to 80% of new) means that it > always cranks the engine and will provide a > quantified option for dealing with alternator > failure. Two batteries just doubles your > preventative maintenance labor. Further, > you need to decide if plan-b can reliably > depend on the sum total of energy in two > batteries . . . or will they be sized to > independently step up to the task? The > second option calls for 2X the battery > weight and volume; the first option complicates > calculations and switching operations for > carrying out a plan-b that shouldn't ever > happen. BOTH options still demand good > preventative maintenance. > > Just as you KNOW fuel aboard when you launch, > you also need to know Watt-Hours aboard > no matter how many batteries you're carrying. > > If you have TWO properly maintained batteries, > in all likelihood, you'll be carrying around > $twice$ the hardware with virtually no value > added to the ship's overall reliability. > > Bob . . . > -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 28 ____________________________________ Time: 04:59:18 PM PST US From: Alec Myers Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus If the maintenance of the primary battery is not always perfect then isnt it very likely that the maintenance of the backup battery is also not perfect? If human factors are at play, then is it not likely that two batteries will get even more imperfect maintenance than one? After all, who needs to maintain their battery when theres a backup battery installed? On Jun 8, 2020, at 7:17 PM, Ken Ryan wrote: Thanks Charlie, I am convinced that 2 alternators + 1 battery is superior to 1 alternator + 2 batteries. I am less convinced that if two alternators are not possible, a second battery adds virtually no value to the ship's overall reliability. Bob did make a pretty good argument, but it is founded on the assumption that the battery, when properly maintained, is utterly reliable. I have two problems with that assumption: 1) we know from Joe's experience that batteries can fail and 2) even with the best of intentions, maintenance (including battery maintenance) is not always perfect. To contend that having a fresh battery available at the flip of a switch adds no reliability to an electrically dependent aircraft still seems like a bit of a stretch to me. Ken On Mon, Jun 8, 2020 at 2:49 PM Charlie England wrote: Hi Ken, I'll take a swing at it, but would suggest that it's not quite the right question. I get your point, but the answer 'depends'. If using electronic fuel injection, the current demands mean that a single PC680 style battery (in 'new' condition) will only buy you about 30-40 minutes of flight time after alternator failure. A 2nd PC680 only adds another 30-40 minutes. On an engine that allows two alts, either of which can keep the engine running and the panel lit, a typical alt (ex: 55A Denso) is lighter than a 2nd battery, not much more expensive (actually much cheaper than an actual Odyssey branded PC680), will keep the engine running to fuel exhaustion, and has the additional benefit of allowing a return flight (in some range-dependent situations) without the need of maintenance while on the road. Not something I would ever consider after an alt failure with only a 2nd bat for backup. Add to the mix, the fact that while a 2nd alt is pretty much an install&forget item (just a startup check each flight similar to a mag check), any battery is a constantly degrading item that requires regular capacity testing to ensure that it has enough remaining capacity to give expected duration if called upon. Now, with carb or mech fuel injection in a VFR environment, current demands might (likely will) be low enough that a single bat & single alt back up each other. In *my* opinion, that's where Bob's statement makes sense, and where your question, as framed, doesn't need asking. So, I think you really have to define both the mission *and the hardware* to pick an architecture. FWIW, Charlie On Mon, Jun 8, 2020 at 11:15 AM Ken Ryan wrote: Bob, you said: "If you have TWO properly maintained batteries, in all likelihood, you'll be carrying around $twice$ the hardware with virtually no value added to the ship's overall reliability." Help me understand why the following statement is not correct: If you have TWO properly maintained alternators, plus a battery (sized for minimum endurance requirements) in all likelihood, you'll be carrying around $twice$ the hardware with virtually no value added to the ship's overall reliability. Ken On Sun, Jun 7, 2020 at 6:56 PM Robert L. Nuckolls, III wrote: At 05:26 PM 6/7/2020, you wrote: > I am not speaking to any engine manufacturers recommendation (although the > Honda Viking manufacturer does recommend two batteries. I just thought > I was applying logic -- if dual alternator + battery (triple power source) > is desirable for electrically dependent engines, wouldn't that reasoning > imply that if the second alternator is not practical, a second battery > could be used as the third power source? I could ask you a similar question: > Are not two independent power sources (battery and alternator) sufficient > to meet the needs of the electrically dependent engine. Obviously you > saw value in adding the second alternator. Why no value in adding the second battery? Excellent question. It's a problem in energy budgets combined with efforts to assure continued airworthiness. The airplane cannot do without a battery if you're going to have a starter. Depending on your planned mission profiles, you will want to size the battery (1) for cranking then (2) minimum endurance in alternator-out modes. This study gave impetus for the creation of the endurance bus . . . a fast and predictable way to economically tap known quantity of energy stored in the battery's chemistry. Z13/8 was a small but significant amplification of that idea . . . the second alternator's endurance had no practical limits. Hence, energy on the chemistry just might be held completely in reserve for descent and approach to landing. Z13/20 (and the aux alternator option on Z101) expanded the Z13/8 endurance opportunity by a factor of 2.5 or better. Okay, suppose the drive pad isn't available. We are still charged with identifying and the delivering to energy required to comfortably terminate a worst-case mission. This means that as a part of routine maintenance the ship's chemistry needs to be monitored for capability. We could certainly store that energy on TWO devices but to what advantage? If we're laboring under the notion that a battery can suddenly become unavailable during one tank of gas, then we have to assume that EITHER battery can roll over and die . . . okay, how would that failure be annunciated . . . how would remaining energy be managed . . . ? I think that's the scenario anticipated by the folks that crafted that battery manager with a full-wave rectifier that -anded- two, completely isolated batteries together. Assume the alternator has quit and some time later one battery craps out. How does the pilot become aware of the problem and what kind of energy juggling issues are presented when the available energy drops to half? This assuming he really knows that the two batteries were performing equally and has recently quantified their condition, he now has to come up with a new "plan C?" and perhaps declare an emergency. This scenario first assumes TWO critical failures during the consumption of one tank of fuel . . . about 3-4 hour window. Part 23 certs don't get concerned with dual failures at all. Part 25 and heavier will wade into the reliability quagmire with mountains of computer generated probability studies that get 'worked' on until somebody finally sprinkles the holy water and off they go. Ask Capt. Sullivan what he thinks about reliability studies . . . https://www.youtube.com/watch?v=HKJ1lIh2Cgk So we're left to our own devices which in reality are not so bad. The short answer is: A diligently maintained battery is the most reliable source of energy on the airplane. Replacing it when ability to store energy drops below some benchmark (generally 75 to 80% of new) means that it always cranks the engine and will provide a quantified option for dealing with alternator failure. Two batteries just doubles your preventative maintenance labor. Further, you need to decide if plan-b can reliably depend on the sum total of energy in two batteries . . . or will they be sized to independently step up to the task? The second option calls for 2X the battery weight and volume; the first option complicates calculations and switching operations for carrying out a plan-b that shouldn't ever happen. BOTH options still demand good preventative maintenance. Just as you KNOW fuel aboard when you launch, you also need to know Watt-Hours aboard no matter how many batteries you're carrying. If you have TWO properly maintained batteries, in all likelihood, you'll be carrying around $twice$ the hardware with virtually no value added to the ship's overall reliability. Bob . . . ________________________________ Message 29 ____________________________________ Time: 05:07:59 PM PST US From: Ken Ryan Subject: Re: AeroElectric-List: Physical construction of Z101 engine bus & battery bus I see definite advantage in a second battery, IN ADDITION to a battery sized and maintained to meet endurance goals. The advantage is obvious, added protection. Joe had a sudden and complete battery failure, so we know that batteries can and do fail. But more importantly, although Bob has stressed the need to know how many electrons are in the battery is as important as knowing how much fuel is in the tank, unfortunately one cannot put a dipstick in a battery and read with certainty what is in there. And as I said, even with the best of intentions, maintenance does not always get done correctly or on schedule. Add to that the fact that the battery can easily suffer abuse, simply by experiencing problems starting the engine, or leaving the master switch on; both are events that can seriously degrade a battery's capacity. To me, it is not a stretch at all to believe that even a conscientious owner might take off unknowingly with a battery whose capacity is far less than what he believes it to be. Again, it seems the hesitance to endorse two batteries is primarily based on the assumption that batteries are very reliable and completely knowable. Do we want to bet our lives on that assumption? On Mon, Jun 8, 2020 at 3:39 PM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > If you don=C3=A2=82=AC=84=A2t have a second alternator, you should have a small backup > battery. Sizing would depend on your typical/ maximum distance between > airports. Current draw of the pump, ECU, injectors and coils would be > around 12 to 14 amps. A 12 amp/hour battery should give you a solid 30-40 > minutes of flight time, just running the engine electrics. An 18 amp/hour > one, around 1 hour. We want to be able to sustain at least 10 volts to th e > electrics. > > > *We=C3=A2=82=AC=84=A2ve found the most reliable, simple and light w ay to get backup > battery power to the engine electrics is a single 12 to 14 gauge wire > running from the backup battery, through a 30 amp ATO fuse, to a heavy du ty > switch, to an emergency buss where all the engine electrics can receive > power. Simply charge the backup battery every 30 days and load test > annually. *If you have the recommended check engine light fitted, it will > warn you any time the battery voltage falls below 12.5V. You can monitor > battery voltage in Gauge 3 mode. > > > A statement that is understandable and predictable. > EVERY supplier of electrically dependent aircraft > accessories has a vested interest in NOT having > their product figure into the script for your > bad day in the cockpit. > > Their "most reliable finding" focuses on > their product . . . and while certainly > critical for continued flight, it's not > the only critical electro-whizzie on the > airplane. > > All creative assemblages stand on the 3-legged > stool of energy-management, properties-of- > materials and refinement-of-process. It doesn't > matter if you're cooking breakfast or building a > space shuttle. > > I think I've suggested before that installation > manuals for such products should call for, "Energy > supplied by a robust, failure tolerant and competently > maintained electrical system." > > To be sure . . . many of our brothers don't > have strong interests or appreciation for > elegant solutions and prefer the cookie-cutter > approach. Nothing overtly wrong with that > but it can generate systems with high > costs of ownership, unnecessary weight > and complexity. Complexity adds risk for lack of > understanding and mis-application of features > originally intended to keep a tense day > in the cockpit from getting worst. > > We don't do gps receivers here . . . or engines, > or auto-pilots. We do system integration with > a goal of achieving the simplest, failure tolerant > supply and distribution systems. A natural fallout > of those endeavors is lower cost of ownership > and weight. > > Getting back to the subject engine, what's > the 'advantage' of carrying a second battery > that may never be used as opposed to carrying > one battery sized and maintained to meet > what ever endurance goals are sought for > the whole airplane? > > Bob . . . > ________________________________ Message 30 ____________________________________ Time: 05:15:24 PM PST US Subject: AeroElectric-List: Re: Physical construction of Z101 engine bus & battery bus From: "user9253" I confirm that my PC680 failed while in flight. I sent it to Bob. He opened it up and found a broken weld. I can not remember how old the battery was, probably 5 years or more. That battery cranked the engine just fine on that last flight. I did not realize the battery had failed until I reduced engine RPM prior to landing. The alternator had been supplying power up to that point. While battery failure is extremely rare, it can happen. If an aircraft has two batteries, a new one can be installed every other year. Worst case is that one battery will be 4 years old and the other one 2 years old. I am not necessarily recommending two batteries. Having two batteries will give some pilots peace of mind, even though heavier and more expensive. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=496709#496709 ________________________________ Message 31 ____________________________________ Time: 06:08:26 PM PST US Subject: AeroElectric-List: Re: Exploring a Different Way to Wire Avionics From: "donjohnston" When I bought my Approach FastStack, I had them make the cables I needed at the time because it wasn't that much money. As things changed, I made my own cables. The nice part is when you swap out a device, you just make a new cable for the connection between the device and the hub. Most interconnects between devices are done in the hub. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=496712#496712 ________________________________ Message 32 ____________________________________ Time: 06:56:23 PM PST US Subject: Re: AeroElectric-List: Re: Exploring a Different Way to Wire Avionics From: Charlie England On 6/8/2020 8:04 PM, donjohnston wrote: > > When I bought my Approach FastStack, I had them make the cables I needed at the time because it wasn't that much money. As things changed, I made my own cables. > > The nice part is when you swap out a device, you just make a new cable for the connection between the device and the hub. Most interconnects between devices are done in the hub. > Were all the connections 1-1, 2-2, etc, or did you have to rearrange pin order? -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.