---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 10/07/11: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:23 AM - Re: AeroElectric-List Digest: 2 Msgs - 10/06/11 (K Fohringer) 2. 11:47 AM - Electric aircraft issues (Les Goldner) 3. 01:39 PM - Re: Electric aircraft issues (Robert L. Nuckolls, III) 4. 02:08 PM - Re: Electric aircraft issues (Marvin Haught) 5. 02:41 PM - Re: Electric aircraft issues (Bill Watson) 6. 04:09 PM - Re: Electric aircraft issues (Bill Boyd) ________________________________ Message 1 _____________________________________ Time: 12:23:06 AM PST US From: "K Fohringer" Subject: AeroElectric-List: RE: AeroElectric-List Digest: 2 Msgs - 10/06/11 ________________________________ Message 2 _____________________________________ Time: 11:47:24 AM PST US From: "Les Goldner" Subject: AeroElectric-List: Electric aircraft issues Bob, or anyone else out there in Aeroelectric land with Li-Ion battery knowledge, I have started to build, what I hope will be, an electric aircraft. The kit, a Cumulus motor glider , with a 20:1 glide ratio is ideal, and I have non-explosive A123 batteries . The 560 batteries, 25HP/100V electric motor, and controller should weigh in about the same as and fly as long as it would with the prescribed Rotax engine. With a potential to fly about 2000 cycles (read 2000 flights), these batteries will cost about 20% of the cost of mogas. if I can figure out how to configure the batteries and charge them properly. I could use a lot of advice regarding the battery pack architecture, charging, and maintaining these Li-Ion batteries. I need to know how to weld or solder the batteries into packs (I am thinking 32 packs places in series; each pack having 16 or 17 cells in parallel). I need to find an inexpensive way to charge them (I am thinking I could charge the 8 packs at a time; 30V @ 50A for up to 45 minutes) but need to understand more about charging and balancing. A123 won't give me the time of day since they changed their focus to sell batteries only to auto manufacturers so any words of wisdom would be helpful. Thanks, Les ________________________________ Message 3 _____________________________________ Time: 01:39:22 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Electric aircraft issues At 01:43 PM 10/7/2011, you wrote: Bob, or anyone else out there in Aeroelectric land with Li-Ion battery knowledge, I have started to build, what I hope will be, an electric aircraft. The kit, a Cumulus motor glider, with a 20:1 glide ratio is ideal, and I have non-explosive A123 batteries. The 560 batteries, 25HP/100V electric motor, and controller should weigh in about the same as and fly as long as it would with the prescribed Rotax engine. With a potential to fly about 2000 cycles (read 2000 flights), these batteries will cost about 20% of the cost of mogas if I can figure out how to configure the batteries and charge them properly. I could use a lot of advice regarding the battery pack architecture, charging, and maintaining these Li-Ion batteries. I need to know how to weld or solder the batteries into packs (I am thinking 32 packs places in series; each pack having 16 or 17 cells in parallel). I need to find an inexpensive way to charge them (I am thinking I could charge the 8 packs at a time; 30V @ 50A for up to 45 minutes) but need to understand more about charging and balancing. A123 wont give me the time of day since they changed their focus to sell batteries only to auto manufacturers so any words of wisdom would be helpful. Thanks, Les I wish that the bright light at the end of the tunnel was not an oncoming train. There has been an intense interest in lighter/ more energetic batteries for aircraft since Cessna bolted batteries and generators to the C-140 many moons ago. There have been some fits and starts on lithium devices with mixed results. There ARE lithium products flying on a number of air transport category aircraft. Until a short time ago, Cessna had sold several Citations with lithium starting batteries aboard. Cessna had invested mucho bux in a development program that for all intents and purposes, produced an airworthy product. Then we have these two documents: SL525C-24-02A-R01 SB525C-24-05 The background on these publications seems to stand on a battery fire in a factory airplane that caused extensive damage and was difficult to control. It seems that the battery monitoring system may have failed to predict and warn against a 'normal' recharge of a badly depleted battery. Hence an field investigation into software issues. The other document speaks to what's necessary to replace a lithium battery with either lead-acid or ni-cad with only a logbook entry. This document does not speak to a Cessna program that proposes to replace all lithium products from the field. I'm not ready to recommend that anyone bolt a lithium device to their airplane. When the big guys are stubbing their toes in spectacular ways, I think it unwise to think that we are well advised to expand a technology (that is still an experiment) into our fun machines. By the way, I think the cells involved in the battery fire were the Lithium Iron devices from A123. The fat lady hasn't even been handed the sheet music much less received a curtain call. I'll continue to track this series of events. It sound like you'd like to be involved in the development of a next generation aircraft. There are a number of good texts on battery management. I'll see if I can get some titles and sources for you. Bob . . . ________________________________ Message 4 _____________________________________ Time: 02:08:24 PM PST US From: Marvin Haught Subject: Re: AeroElectric-List: Electric aircraft issues I'd be interested in information about building battery packs and welding or soldering those batteries into battery packs. I just bought a Li-on pack for my CPAP machine - $359! I'd love to try building my own battery pack for a couple of purposes if I can do so safely and gain some education. M. Haught On 10/7/2011 3:34 PM, Robert L. Nuckolls, III wrote: > > > > At 01:43 PM 10/7/2011, you wrote: > > Bob, or anyone else out there in Aeroelectric land with Li-Ion battery > knowledge, > I have started to build, what I hope will be, an electric aircraft. > The kit, a Cumulus motor glider, with a 20:1 glide ratio is ideal, and > I have non-explosive A123 batteries. The 560 batteries, 25HP/100V > electric motor, and controller should weigh in about the same as and > fly as long as it would with the prescribed Rotax engine. With a > potential to fly about 2000 cycles (read 2000 flights), these > batteries will cost about 20% of the cost of mogas if I can figure > out how to configure the batteries and charge them properly. > > I could use a lot of advice regarding the battery pack architecture, > charging, and maintaining these Li-Ion batteries. I need to know how > to weld or solder the batteries into packs (I am thinking 32 packs > places in series; each pack having 16 or 17 cells in parallel). I need > to find an inexpensive way to charge them (I am thinking I could > charge the 8 packs at a time; 30V @ 50A for up to 45 minutes) but need > to understand more about charging and balancing. > > A123 wont give me the time of day since they changed their focus to > sell batteries only to auto manufacturers so any words of wisdom would > be helpful. > Thanks, > Les > > I wish that the bright light at the end of > the tunnel was not an oncoming train. > > There has been an intense interest in lighter/ > more energetic batteries for aircraft since > Cessna bolted batteries and generators to the > C-140 many moons ago. > > There have been some fits and starts on lithium > devices with mixed results. There ARE lithium > products flying on a number of air transport > category aircraft. Until a short time ago, > Cessna had sold several Citations with lithium > starting batteries aboard. Cessna had invested > mucho bux in a development program that for all > intents and purposes, produced an airworthy > product. Then we have these two documents: > > > SL525C-24-02A-R01 > > > SB525C-24-05 > > > The background on these publications seems to > stand on a battery fire in a factory airplane > that caused extensive damage and was difficult > to control. > > It seems that the battery monitoring system may > have failed to predict and warn against a 'normal' > recharge of a badly depleted battery. Hence an > field investigation into software issues. The > other document speaks to what's necessary to replace > a lithium battery with either lead-acid or ni-cad > with only a logbook entry. This document does > not speak to a Cessna program that proposes to replace > all lithium products from the field. > > I'm not ready to recommend that anyone bolt > a lithium device to their airplane. When the > big guys are stubbing their toes in spectacular > ways, I think it unwise to think that we are > well advised to expand a technology (that > is still an experiment) into our fun machines. > > By the way, I think the cells involved in the > battery fire were the Lithium Iron devices from > A123. The fat lady hasn't even been handed the > sheet music much less received a curtain call. > I'll continue to track this series of events. > > It sound like you'd like to be involved in the > development of a next generation aircraft. There > are a number of good texts on battery management. > I'll see if I can get some titles and sources > for you. > > > Bob . . . > > -- H.Marvin Haught Jr. Haught& Associates, Inc Huntsville, AR 72740 ________________________________ Message 5 _____________________________________ Time: 02:41:31 PM PST US From: Bill Watson Subject: Re: AeroElectric-List: Electric aircraft issues I'm thinking that getting to the team is working on Monnett's Waiex project would be where some of the most current and directly applied knowledge could be found. Bill On 10/7/2011 2:43 PM, Les Goldner wrote: > > Bob, or anyone else out there in Aeroelectric land with Li-Ion battery > knowledge, > > I have started to build, what I hope will be, an electric aircraft. > The kit, a Cumulus motor glider > , with a 20:1 glide ratio > is ideal, and I have non-explosive A123 batteries > . > The 560 batteries, 25HP/100V electric motor, and controller should > weigh in about the same as and fly as long as it would with the > prescribed Rotax engine. With a potential to fly about 2000 cycles > (read 2000 flights), these batteries will cost about 20% of the cost > of mogas... if I can figure out how to configure the batteries and > charge them properly. > > I could use a lot of advice regarding the battery pack architecture, > charging, and maintaining these Li-Ion batteries. I need to know how > to weld or solder the batteries into packs (I am thinking 32 packs > places in series; each pack having 16 or 17 cells in parallel). I need > to find an inexpensive way to charge them (I am thinking I could > charge the 8 packs at a time; 30V @ 50A for up to 45 minutes) but need > to understand more about charging and balancing. > > A123 won't give me the time of day since they changed their focus to > sell batteries only to auto manufacturers so any words of wisdom would > be helpful. > > Thanks, > Les > > * > > > * ________________________________ Message 6 _____________________________________ Time: 04:09:23 PM PST US Subject: Re: AeroElectric-List: Electric aircraft issues From: Bill Boyd There's a vendor on HFPack who is pretty knowledgable about the A123's as h e sells them to hams interested in pedestrian mobile operations - not that he knows anything about aircraft, but he probably has the typical ham operator's willingness to help a fellow experimenter all he can - a lot lik e Bob N, here ;) Google it. -Bill B On Fri, Oct 7, 2011 at 5:38 PM, Bill Watson wrote: > I'm thinking that getting to the team is working on Monnett's Waiex > project would be where some of the most current and directly applied > knowledge could be found. > > Bill > > > On 10/7/2011 2:43 PM, Les Goldner wrote: > > Bob, or anyone else out there in Aeroelectric land with Li-Ion battery > knowledge,**** > > I have started to build, what I hope will be, an electric aircraft. The > kit, a Cumulus motor glider , > with a 20:1 glide ratio is ideal, and I have non-explosive A123 batteries . > The 560 batteries, 25HP/100V electric motor, and controller should weigh in > about the same as and fly as long as it would with the prescribed Rotax > engine. With a potential to fly about 2000 cycles (read 2000 flights), th ese > batteries will cost about 20% of the cost of mogas=85 if I can figure out how > to configure the batteries and charge them properly.**** > > I could use a lot of advice regarding the battery pack architecture, > charging, and maintaining these Li-Ion batteries. I need to know how to w eld > or solder the batteries into packs (I am thinking 32 packs places in seri es; > each pack having 16 or 17 cells in parallel). I need to find an inexpensi ve > way to charge them (I am thinking I could charge the 8 packs at a time; 3 0V > @ 50A for up to 45 minutes) but need to understand more about charging an d > balancing.**** > > A123 won=92t give me the time of day since they changed their focus to se ll > batteries only to auto manufacturers so any words of wisdom would be > helpful.**** > > Thanks, > Les **** > > * > > * > > > * > =========== > =========== =========== =========== > > * > > ------------------------------------------------------------------------------------- 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.