---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 03/17/14: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:45 AM - Re: Lithium batteries (Robert L. Nuckolls, III) 2. 09:27 AM - New Over-Voltage Protection Architecture (user9253) 3. 09:41 AM - EarthX lithium (Robert L. Nuckolls, III) 4. 09:49 AM - Re: New Over-Voltage Protection Architecture (Robert L. Nuckolls, III) 5. 09:57 AM - EarthX lithium (Robert L. Nuckolls, III) 6. 10:22 AM - Re: New Over-Voltage Protection Architecture (user9253) 7. 10:46 AM - Re: EarthX lithium (Robert Borger) 8. 11:18 AM - Re: EarthX lithium (Robert L. Nuckolls, III) 9. 11:21 AM - Re: Re: New Over-Voltage Protection Architecture (Robert L. Nuckolls, III) 10. 12:02 PM - Re: EarthX lithium (Robert Borger) ________________________________ Message 1 _____________________________________ Time: 06:45:30 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Lithium batteries At 08:53 PM 3/15/2014, you wrote: > > >Mr. Brent Regan is apparently an expert on the use of Lithium batteries in >aircraft. I attempted to start a discussion on the LML list a few years ago >and he shut me down with his expertise. You may want to tap into his >exhaustive research on the subject: >http://lancair.net/lists/lml/Message/57030-P.txt Brent and I have crossed paths in the past but I'm having trouble recalling now when, where and in what context. I'll drop him a note and see if he would be willing to collaborate on the last installment of the series on batteries. Thanks for the heads-up! Bob . . . ________________________________ Message 2 _____________________________________ Time: 09:27:28 AM PST US Subject: AeroElectric-List: New Over-Voltage Protection Architecture From: "user9253" Suppose that it is not desired that a crowbar type over-voltage protection device to have the ability to disable the alternator on an aircraft with an electrically dependent engine or electrically dependent instruments. In the event that an externally regulated alternator puts out too high voltage, is it feasible for the O.V. protection device to insert a series resistance into the alternator field circuit instead of shorting it out? The amount of resistance could be determined through trial and error to give 12-13 volts with normal aircraft loads. Or a resistor could be permanently installed in the alternator field circuit, but normally shorted out by the O.V. protection device. In case of high voltage or O.V. protection malfunction, the short across the resistor will be opened. The alternator will then operate at reduced output determined by the load. A low voltage warning will be indicated to the pilot who can increase or decrease aircraft loads to fine tune the system voltage if desired. No circuit breaker will pop nor will a fuse blow. The pilot or mechanic can troubleshoot the low voltage condition after landing. The advantage of this method of over-voltage protection is that the alternator output will be reduced instead of completely disabled. Question is, is it practical and feasible? Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420469#420469 ________________________________ Message 3 _____________________________________ Time: 09:41:54 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: EarthX lithium I just became aware of EarthX batteries based on comments here on the list. I visited their website and studied a variety of assertions and comparisons designed to promote sales. At first blush, these folks are hanging their marketing hats on the same philosophy as other suppliers of lithium technologies. See attached document . . . The DEARTH of good engineering data for these products makes it difficult if not impossible to craft a well considered integration of the current COTS (commericial off the shelf) offerings onto airplanes. I had to delay submission of the last of four Kitplanes articles for a month . . . not because theres a paucity of choices . . . but because the folks selling them can't define performance in rational numbers. Still digging . . . Bob . . . ________________________________ Message 4 _____________________________________ Time: 09:49:31 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: New Over-Voltage Protection Architecture At 11:26 AM 3/17/2014, you wrote: Suppose that it is not desired that a crowbar type over-voltage protection device to have the ability to disable the alternator on an aircraft with an electrically dependent engine or electrically dependent instruments. In the event that an externally regulated alternator puts out too high voltage, is it feasible for the O.V. protection device to insert a series resistance into the alternator field circuit instead of shorting it out? The amount of resistance could be determined through trial and error to give 12-13 volts with normal aircraft loads. Why not just switch in a stand-by regulator? http://tinyurl.com/npya5l7 . . .they're really cheap . . . In the early days of the alternator fitted C337 and Barons, controlled stand-by regulators were part of the system . . . Or a resistor could be permanently installed in the alternator field circuit, but normally shorted out by the O.V. protection device. In case of high voltage or O.V. protection malfunction, the short across the resistor will be opened. The alternator will then operate at reduced output determined by the load. A low voltage warning will be indicated to the pilot who can increase or decrease aircraft loads to fine tune the system voltage if desired. No circuit breaker will pop nor will a fuse blow. The pilot or mechanic can troubleshoot the low voltage condition after landing. The advantage of this method of over-voltage protection is that the alternator output will be reduced instead of completely disabled. Question is, is it practical and feasible? Pretty tough to sell . . . a voltage regulator is an exceedingly agile device that will willingly produce any field excitation level from near zero to full bus voltage depending on loads and rpm. You could conduct some experiments on your airplane to deduce the size of such a resistor but . . . but be sure to explore the "non nominal" conditions to assess performance. Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:57:06 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: EarthX lithium Skip, Had a reader recommend EarthX lithium batteries for airplanes. Seems they're courting Van's and some other suppliers of kit aircraft and parts. Downloaded a page of their marketing pitch. I commented on it and published it back to my forum. I'm going to contact EarthX for more information on ENERGY numbers and a functional description of their 'battery management system'. See attached . . . Bob . . . ________________________________ Message 6 _____________________________________ Time: 10:22:52 AM PST US Subject: AeroElectric-List: Re: New Over-Voltage Protection Architecture From: "user9253" > Why not just switch in a stand-by regulator? > http://tinyurl.com/npya5l7 > . . .they're really cheap . . . > Great idea. Thanks Bob My RV-12 has a permanent magnet alternator. So I can not try out the series resistor idea. I like to think about alternative ways of wiring an airplane. Most of the time, the old way is the best way. :-) Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420475#420475 ________________________________ Message 7 _____________________________________ Time: 10:46:58 AM PST US Subject: Re: AeroElectric-List: EarthX lithium From: Robert Borger Bob N, In your commentary on the FAQ. At the end there is a question about deeply discharging the battery. Your comment is So if I go off and leave the master switch ON, odds are that by the time I get back to fly again, my battery is trash? I can answer that in one word - YES. Your battery is trash. If this battery is like the one I purchased to test, it does not have a BMS which auto-disconnects to protect cells from over-discharge. I flew with this battery for several months and did some simple ground testing. Tested things like - How long would it last running all the electrics (EIS, EFIS, radio & transponder), how long just running the EIS, radio & transponder, how long just running the EIS & radio and how long just running the EIS & transponder? After each test I put the high-tech charger on and recharged with the cell balance in effect. I didnt get to the last of the questions because after the EIS, radio & transponder test I managed to put the charger on but left the Master on as well. When I came back a couple days later to continue the testing the battery was fully discharged and would not accept recharging. It was trashed. FYI, in testing the battery I found that it would run the whole electrical system about 5 minutes. It would run the EIS, radio & transponder about 7 minutes. Overall, I was not impressed with the LiFePo battery. It was extremely light and it started my Rotax 914 quickly and easily. After starting the engine and flying for a while, it would be properly and fully charged when back on the ground. Unfortunately, from my limited testing, it didnt have any real legs to run things on its own and it requires a lot of fancy, high-tech, gear to keep it happy. And take great care not discharge it fully. Just my 2 from my very limited experience. Blue skies & tailwinds, Bob Borger Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs). Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP 3705 Lynchburg Dr. Corinth, TX 76208-5331 Cel: 817-992-1117 rlborger@mac.com On Mar 17, 2014, at 11:40 AM, Robert L. Nuckolls, III wrote: I just became aware of EarthX batteries based on comments here on the list. I visited their website and studied a variety of assertions and comparisons designed to promote sales. At first blush, these folks are hanging their marketing hats on the same philosophy as other suppliers of lithium technologies. See attached document . . . The DEARTH of good engineering data for these products makes it difficult if not impossible to craft a well considered integration of the current COTS (commericial off the shelf) offerings onto airplanes. I had to delay submission of the last of four Kitplanes articles for a month . . . not because theres a paucity of choices . . . but because the folks selling them can't define performance in rational numbers. Still digging . . . Bob . . . ________________________________ Message 8 _____________________________________ Time: 11:18:46 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: EarthX lithium At 12:46 PM 3/17/2014, you wrote: Bob N, In your commentary on the FAQ. At the end there is a question about deeply discharging the battery. Your comment is =93So if I go off and leave the master switch ON, odds are that by the time I get back to fly again, my battery is trash? I can answer that in one word - YES. Your battery is trash. If this battery is like the one I purchased to test, it does not have a =93BMS=94 which auto-disconnects to protect cells from over-discharge. Which part number of battery did you test? I flew with this battery for several months and did some simple ground testing. Tested things like - How long would it last running all the electrics (EIS, EFIS, radio & transponder), how long just running the EIS, radio & transponder, how long just running the EIS & radio and how long just running the EIS & transponder? After each test I put the high-tech charger on and recharged with the cell balance in effect. I didn=92t get to the last of the questions because after the EIS, radio & transponder test I managed to put the charger on but left the Master on as well. When I came back a couple days later to continue the testing the battery was fully discharged and would not accept recharging. It was trashed. Good data point . . . FYI, in testing the battery I found that it would run the whole electrical system about 5 minutes. It would run the EIS, radio & transponder about 7 minutes. Overall, I was not impressed with the LiFePo battery. It was extremely light and it started my Rotax 914 quickly and easily. After starting the engine and flying for a while, it would be properly and fully charged when back on the ground. Unfortunately, from my limited testing, it didn=92t have any real legs to run things on its own and it requires a lot of fancy, high-tech, gear to keep it happy. And take great care not discharge it fully. Just my 2=A2 from my very limited experience. From your limited observations, what would you estimate the energy content to be for the model you tested? In other words, what was the demand for the EIS, radio and transponder? Apparently it would satisfactorily crank an engine for some time. I have emailed EarthX requesting the name and address for an individual who can supply technical date in detail sufficient to make good system integration choices. Thanks for the data points! Bob . . . ________________________________ Message 9 _____________________________________ Time: 11:21:57 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: New Over-Voltage Protection Architecture >Great idea. Thanks Bob >My RV-12 has a permanent magnet alternator. So I can not try out >the series resistor idea. I like to think about alternative ways of >wiring an airplane. Most of the time, the old way is the best way. ALL ways are worthy of considered thought. It's just as valuable to know what DOES work as those things which are QUESTIONABLE. I've often asked builders to get on the List and tell us what was tried that didn't work . . . like Bob's posting on EarthX . . . It helps avoid discovering a bad idea over and over again! Bob . . . ________________________________ Message 10 ____________________________________ Time: 12:02:03 PM PST US Subject: Re: AeroElectric-List: EarthX lithium From: Robert Borger Bob N, LiFePo battery - AeroVoltz 8 Cell Lithium Battery. http://aerovoltz.net/en/ The Sport EFIS consumes about 1 amp according to the documentation. I don=92t have good numbers on the GRT EIS4000 but I would allow about 1 amp with all the sensors, back light, display, etc. I may be able to get a better number next trip to the hanger. The radio and transponder are MicroAir M760Q & T2000 SFL. =46rom the documentation, I=92d say they each use about 250-300ma with the backlight on and not transmitting. The battery turned the 914 over very smartly. The engine is easy to start in any case so it wasn=92t really working that hard. Three or 4 prop blades and it starts. That=92s 2 or 3 rotations of the engine. Blue skies & tailwinds, Bob Borger Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs). Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP 3705 Lynchburg Dr. Corinth, TX 76208-5331 Cel: 817-992-1117 rlborger@mac.com On Mar 17, 2014, at 1:17 PM, Robert L. Nuckolls, III wrote: At 12:46 PM 3/17/2014, you wrote: Bob N, In your commentary on the FAQ. At the end there is a question about deeply discharging the battery. Your comment is =93So if I go off and leave the master switch ON, odds are that by the time I get back to fly again, my battery is trash? I can answer that in one word - YES. Your battery is trash. If this battery is like the one I purchased to test, it does not have a =93BMS=94 which auto-disconnects to protect cells from over-discharge. Which part number of battery did you test? I flew with this battery for several months and did some simple ground testing. Tested things like - How long would it last running all the electrics (EIS, EFIS, radio & transponder), how long just running the EIS, radio & transponder, how long just running the EIS & radio and how long just running the EIS & transponder? After each test I put the high-tech charger on and recharged with the cell balance in effect. I didn=92t get to the last of the questions because after the EIS, radio & transponder test I managed to put the charger on but left the Master on as well. When I came back a couple days later to continue the testing the battery was fully discharged and would not accept recharging. It was trashed. Good data point . . . FYI, in testing the battery I found that it would run the whole electrical system about 5 minutes. It would run the EIS, radio & transponder about 7 minutes. Overall, I was not impressed with the LiFePo battery. It was extremely light and it started my Rotax 914 quickly and easily. After starting the engine and flying for a while, it would be properly and fully charged when back on the ground. Unfortunately, from my limited testing, it didn=92t have any real legs to run things on its own and it requires a lot of fancy, high-tech, gear to keep it happy. And take great care not discharge it fully. Just my 2=A2 from my very limited experience. =46rom your limited observations, what would you estimate the energy content to be for the model you tested? In other words, what was the demand for the EIS, radio and transponder? Apparently it would satisfactorily crank an engine for some time. I have emailed EarthX requesting the name and address for an individual who can supply technical date in detail sufficient to make good system integration choices. Thanks for the data points! Bob . . . ------------------------------------------------------------------------------------- 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.