---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 03/21/17: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:48 AM - Lightweight rechargeable battery backup unit (BobD) 2. 06:12 AM - Re: Lightweight rechargeable battery backup unit (Charlie England) 3. 07:07 AM - Re: Lightweight rechargeable battery backup unit (user9253) 4. 08:08 AM - Re: Re: Lightweight rechargeable battery backup unit (Tcwtech) 5. 08:38 AM - Re: Lightweight rechargeable battery backup unit (BobD) 6. 08:50 AM - Re: Lightweight rechargeable battery backup unit (Jan de Jong) 7. 09:01 AM - Re: Re: Lightweight rechargeable battery backup unit (Tcwtech) 8. 09:39 AM - Re: Re: Lightweight rechargeable battery backup unit (John Cox) 9. 10:25 AM - Re: Lightweight rechargeable battery backup unit (user9253) 10. 10:44 AM - Re: Lightweight rechargeable battery backup unit (user9253) 11. 06:58 PM - Re: Lightweight rechargeable battery backup unit (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 03:48:19 AM PST US Subject: AeroElectric-List: Lightweight rechargeable battery backup unit From: "BobD" Now that the LAA have approved the use of electronic ASI & Altimeter for backup purposes as an alternative to steam driven instruments, I am considering installing a combined unit in my aircraft as a backup to my Dynon Skyview. http://www.lightaircraftassociation.co.uk/engineering/TechnicalLeaflets/Mods%20and%20Repairs/TL%203.20%20EFIS%20in%20LAA%20Aircraft.pdf The pre-approved one I prefer (on clarity and cost grounds) from the LAA document is the MGL ASX-1. However, it has one major drawback in that it does not have a built in battery backup. Having spoken to a distributor, he suggested a 9V PP3 battery (possibly switchable in the circuit) would be sufficient for emergency power if the main circuit failed. However, I would prefer a re-chargeable battery, re-charged through the aircraft system, so as not to have to worry or check that the backup battery is maintained in a charged state. Despite trawling the web, and there being several commercial units and amateur wiring diagrams out there, I have found none that are specific for incorporating in an aircraft. I am reasonably competent with a soldering iron, but less so in the theory of such things, so would be happy to construct my own on a PCB, from a detailed wiring diagram. Does anyone know of such a diagram, or a suitable lightweight and cost effective commercial device suitable for installation behind the Control Panel? -------- Bob Dawson XS TG || 912 ULS || G-NHRJ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=467484#467484 ________________________________ Message 2 _____________________________________ Time: 06:12:59 AM PST US From: Charlie England Subject: Re: AeroElectric-List: Lightweight rechargeable battery backup unit On Tue, Mar 21, 2017 at 5:45 AM, BobD wrote: > > Now that the LAA have approved the use of electronic ASI & Altimeter for > backup purposes as an alternative to steam driven instruments, I am > considering installing a combined unit in my aircraft as a backup to my > Dynon Skyview. > > http://www.lightaircraftassociation.co.uk/engineering/ > TechnicalLeaflets/Mods%20and%20Repairs/TL%203.20%20EFIS% > 20in%20LAA%20Aircraft.pdf > > The pre-approved one I prefer (on clarity and cost grounds) from the LAA > document is the MGL ASX-1. However, it has one major drawback in that it > does not have a built in battery backup. > > Having spoken to a distributor, he suggested a 9V PP3 battery (possibly > switchable in the circuit) would be sufficient for emergency power if the > main circuit failed. However, I would prefer a re-chargeable battery, > re-charged through the aircraft system, so as not to have to worry or check > that the backup battery is maintained in a charged state. Despite trawling > the web, and there being several commercial units and amateur wiring > diagrams out there, I have found none that are specific for incorporating > in an aircraft. > > I am reasonably competent with a soldering iron, but less so in the theory > of such things, so would be happy to construct my own on a PCB, from a > detailed wiring diagram. Does anyone know of such a diagram, or a suitable > lightweight and cost effective commercial device suitable for installation > behind the Control Panel? > > -------- > Bob Dawson > XS TG || 912 ULS || G-NHRJ > > > Have you considered placing the battery 'in series' (**sloppy design speak**) with the supply? If you feed bus voltage to a voltage regulator, then tie the VR's output to the backup battery and the device, the device would be electrically isolated from the bus and always powered by the regulator/backup battery, but the battery would never be discharged. Idea is to set the regulator at the charge point of the backup. If you use an adjustable boost-buck 'switching' regulator, your voltage set point could be the same as your bus voltage, and your backup battery could be the same voltage but lower current version of your main battery. Noise from the 'switcher' could be an issue, but if using a quality power supply, its output should be cleaner than an alternator's output. Simply size the PS to be slightly bigger than the demand of your instrument. An alternative would be the 9V battery and a linear regulator adjusted to the minimum acceptable charge voltage for the 9V battery. Less efficient and more heat, but no noise at all. Charlie ________________________________ Message 3 _____________________________________ Time: 07:07:12 AM PST US Subject: AeroElectric-List: Re: Lightweight rechargeable battery backup unit From: "user9253" How about this circuit? Small rechargeable lead acid batteries are available that weight less than 1 pound. http://www.zbattery.com/Batteries/List-of-All-12Vs -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=467490#467490 Attachments: http://forums.matronics.com//files/backup_battery_104.pdf http://forums.matronics.com//files/backup_battery_291.jpg ________________________________ Message 4 _____________________________________ Time: 08:08:28 AM PST US From: Tcwtech Subject: Re: AeroElectric-List: Re: Lightweight rechargeable battery backup unit I'm aware that many on this list are interested in rolling their own solutions to many things, which is all well and good. For those that are interested in an engineered and proven solution to back-up power for critical avionics I would recommend you visit our web site and review our IBBS series of products. They are a self-contained back-up system with an internal smart charger and power transfer switching. We have been producing these products for 7 years for the experimental and are on the verge of releasing our TSO'd version. Thanks for the consideration, Www.tcwtech.com Bob Newman TCW Technologies, LLC 610-928-3420 > On Mar 21, 2017, at 10:04 AM, user9253 wrote: > > > How about this circuit? > Small rechargeable lead acid batteries are available that weight less than 1 pound. > http://www.zbattery.com/Batteries/List-of-All-12Vs > > -------- > Joe Gores > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=467490#467490 > > > > > Attachments: > > http://forums.matronics.com//files/backup_battery_104.pdf > http://forums.matronics.com//files/backup_battery_291.jpg > > > > > > ________________________________ Message 5 _____________________________________ Time: 08:38:17 AM PST US Subject: AeroElectric-List: Re: Lightweight rechargeable battery backup unit From: "BobD" Bob, Thank You and the other contributors for your replies. Please excuse my ignorance, but having reviewed your IBBS products, even the small unit at 2.5 lbs seems overkill in terms of my requirement, for a potential device to power for up to 30 minutes one low power instrument in VFR conditions. I was hoping to be able to use either rechargeable alkaline, NiCd or NiMH batteries. I hope my expectations aren't too ambitious, as I assume something like this is included within the other Instruments mentioned in the LAA leaflet. Again, the questions are asked because of my limited knowledge [Rolling Eyes] -------- Bob Dawson XS TG || 912 ULS || G-NHRJ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=467495#467495 ________________________________ Message 6 _____________________________________ Time: 08:50:31 AM PST US Subject: Re: AeroElectric-List: Lightweight rechargeable battery backup unit From: Jan de Jong What I would do. Don't forget an on/off function between aux. battery and load (not drawn). Jan de Jong On 3/21/2017 3:04 PM, user9253 wrote: > > How about this circuit? > Small rechargeable lead acid batteries are available that weight less than 1 pound. > http://www.zbattery.com/Batteries/List-of-All-12Vs > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=467490#467490 > > > Attachments: > > http://forums.matronics.com//files/backup_battery_104.pdf > http://forums.matronics.com//files/backup_battery_291.jpg > > ________________________________ Message 7 _____________________________________ Time: 09:01:32 AM PST US From: Tcwtech Subject: Re: AeroElectric-List: Re: Lightweight rechargeable battery backup unit Our smallest product is 3 amp-hrs and weighs in at 18 oz. Bob Newman TCW Technologies, LLC 610-928-3420 > On Mar 21, 2017, at 11:35 AM, BobD wrote: > > > Bob, Thank You and the other contributors for your replies. > > Please excuse my ignorance, but having reviewed your IBBS products, even the small unit at 2.5 lbs seems overkill in terms of my requirement, for a potential device to power for up to 30 minutes one low power instrument in VFR conditions. > > I was hoping to be able to use either rechargeable alkaline, NiCd or NiMH batteries. I hope my expectations aren't too ambitious, as I assume something like this is included within the other Instruments mentioned in the LAA leaflet. > > Again, the questions are asked because of my limited knowledge > [Rolling Eyes] > > -------- > Bob Dawson > XS TG || 912 ULS || G-NHRJ > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=467495#467495 > > > > > > > > > ________________________________ Message 8 _____________________________________ Time: 09:39:30 AM PST US From: John Cox Subject: Re: AeroElectric-List: Re: Lightweight rechargeable battery backup unit I will Second this thoughtful suggestion. John Cox, Retired Airline Avionics tech On Mar 21, 2017 09:08, "Tcwtech" wrote: > > Our smallest product is 3 amp-hrs and weighs in at 18 oz. > > Bob Newman > TCW Technologies, LLC > 610-928-3420 > > > On Mar 21, 2017, at 11:35 AM, BobD wrote: > > > > > > Bob, Thank You and the other contributors for your replies. > > > > Please excuse my ignorance, but having reviewed your IBBS products, even > the small unit at 2.5 lbs seems overkill in terms of my requirement, for a > potential device to power for up to 30 minutes one low power instrument in > VFR conditions. > > > > I was hoping to be able to use either rechargeable alkaline, NiCd or > NiMH batteries. I hope my expectations aren't too ambitious, as I assume > something like this is included within the other Instruments mentioned in > the LAA leaflet. > > > > Again, the questions are asked because of my limited knowledge > > [Rolling Eyes] > > > > -------- > > Bob Dawson > > XS TG || 912 ULS || G-NHRJ > > > > > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=467495#467495 > > > > > > > > > > > > > > > > > > > > ________________________________ Message 9 _____________________________________ Time: 10:25:51 AM PST US Subject: AeroElectric-List: Re: Lightweight rechargeable battery backup unit From: "user9253" You could connect 11 of NiMH AA or AAA cells and 2 diodes all in series. But not much weight will be saved over a small lead acid battery. The more connections there are, the greater the chance of failure. Those AA battery holders with springs are prone to fail. Pre-made 13.2 volt NiMH battery packs are available for an outrageous price. > Don't forget an on/off function between aux. battery and load (not drawn). Good idea. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=467500#467500 ________________________________ Message 10 ____________________________________ Time: 10:44:45 AM PST US Subject: AeroElectric-List: Re: Lightweight rechargeable battery backup unit From: "user9253" This sealed lead acid battery weighs 12 oz. Use a schottky diode to minimize voltage drop. http://www.zbattery.com/Power-Patrol-12v-800mAh-Sealed-SLA1000?sc=2&category=62965 -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=467501#467501 ________________________________ Message 11 ____________________________________ Time: 06:58:27 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Lightweight rechargeable battery backup unit > >Having spoken to a distributor, he suggested a 9V PP3 battery >(possibly switchable in the circuit) would be sufficient for >emergency power if the main circuit failed. However, I would prefer >a re-chargeable battery, re-charged through the aircraft system, so >as not to have to worry or check that the backup battery is >maintained in a charged state. Be cautious here my friend. Consider ANY battery you install for ANY purpose on your airplane . . . batteries are like house plants . . . no, worse than house plants . . . at least you can SEE when the sucker has wilted. Just because you have a set of secondary cells (rechargeable) supported by an outside energy source does not eliminate the need for periodic capacity testing to make sure that battery will meet mission goals when called upon to do its task. Another battery, whether rechargeable or not, becomes another line item on your ship's preventative maintenance list . . . a line item that, unlike your tires, cannot be visually inspected for airworthiness. Tell us about the rest of your airplane. What kind of alternator(s), battery(ies), ignition systems, fuel motivators, etc. Is your engine electrically dependent? If so, how are you reducing risk for loss of electromotive incentives to keep the fan running? Given that so many OBAM aircraft are being configured with a great deal of electrical dependency, then it automatically follows that what ever is planned to keep you airborne is also adequate to keeping you right side up and headed in the right direction. 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