---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 10/27/15: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:04 AM - Earthx LiFePO4 for aircraft (Jan de Jong) 2. 11:04 AM - Re: Earthx LiFePO4 for aircraft (Charlie England) 3. 12:16 PM - Re: Earthx LiFePO4 for aircraft (Jan de Jong) 4. 07:47 PM - Re: Earthx LiFePO4 for aircraft (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 08:04:39 AM PST US From: Jan de Jong Subject: AeroElectric-List: Earthx LiFePO4 for aircraft Just in case I am not the only one to have missed this... Earthx appears to have responded to complaints from aircraftbuilders: http://earthxmotorsports.com/wp-content/uploads/2015/07/ETX_Manual_111017_K.pdf see "Hundred Series" - the battery holds up when the alternator is shut off. Jan de Jong ________________________________ Message 2 _____________________________________ Time: 11:04:26 AM PST US Subject: Re: AeroElectric-List: Earthx LiFePO4 for aircraft From: Charlie England On 10/27/2015 10:02 AM, Jan de Jong wrote: > > > Just in case I am not the only one to have missed this... > > Earthx appears to have responded to complaints from aircraftbuilders: > > http://earthxmotorsports.com/wp-content/uploads/2015/07/ETX_Manual_111017_K.pdf > > see "Hundred Series" - the battery holds up when the alternator is > shut off. > > Jan de Jong While it's likely a viable option for a/c use, their PR people and now, their tech writers, really give me pause. quote from your link: In a lead-acid battery the cells are package in the same case with an acid solution that supports the transfer of charge from higher voltage cells to ones with a lower voltage. unquote. Say What? I've never seen a lead acid battery that shared acid between cells. I also think that they are highly deceptive in claiming that a 6 AH lead acid battery is really only 2 AH. If it were, it would be rated at 2 AH. That 30% number they keep citing is the discharge level for maximum life of the battery; not how much energy can be extracted from it. In a normal environment, the battery would never be discharged below ~90%, and that would be due to a really extended engine start event. In a straight discharge (dead alternator) situation, 6 AH is 6 AH, and 2 AH is 2 AH. Charlie ________________________________ Message 3 _____________________________________ Time: 12:16:28 PM PST US From: Jan de Jong Subject: Re: AeroElectric-List: Earthx LiFePO4 for aircraft I believe it was Shorai who introduced the "PbEq" Ah rating and the factor of 3. So there is some defensive and also some wrong PR in the introductory part of the text. At least in their specifications they quote the actual Ah number in addition to the "PbEq". And they show discharge curves for currents and temperatures. Now they also have, in principle, a correct aircraft battery. I strongly suspect they have a very capable electronics engineer there. But experience will tell. Jan de Jong On 10/27/2015 7:00 PM, Charlie England wrote: > > > On 10/27/2015 10:02 AM, Jan de Jong wrote: >> >> >> Just in case I am not the only one to have missed this... >> >> Earthx appears to have responded to complaints from aircraftbuilders: >> >> http://earthxmotorsports.com/wp-content/uploads/2015/07/ETX_Manual_111017_K.pdf >> >> see "Hundred Series" - the battery holds up when the alternator is >> shut off. >> >> Jan de Jong > While it's likely a viable option for a/c use, their PR people and > now, their tech writers, really give me pause. > quote from your link: > In a lead-acid battery the cells are package in the same case with an > acid solution that supports the transfer of charge from higher voltage > cells to ones with a lower voltage. > unquote. > > Say What? > > I've never seen a lead acid battery that shared acid between cells. > > I also think that they are highly deceptive in claiming that a 6 AH > lead acid battery is really only 2 AH. If it were, it would be rated > at 2 AH. That 30% number they keep citing is the discharge level for > maximum life of the battery; not how much energy can be extracted from > it. In a normal environment, the battery would never be discharged > below ~90%, and that would be due to a really extended engine start > event. In a straight discharge (dead alternator) situation, 6 AH is 6 > AH, and 2 AH is 2 AH. > > Charlie > > ________________________________ Message 4 _____________________________________ Time: 07:47:37 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Earthx LiFePO4 for aircraft > > >Say What? > >I've never seen a lead acid battery that shared acid between cells. > >I also think that they are highly deceptive in claiming that a 6 AH >lead acid battery is really only 2 AH. If it were, it would be rated >at 2 AH. That 30% number they keep citing is the discharge level for >maximum life of the battery; not how much energy can be extracted >from it. In a normal environment, the battery would never be >discharged below ~90%, and that would be due to a really extended >engine start event. In a straight discharge (dead alternator) >situation, 6 AH is 6 AH, and 2 AH is 2 AH. > >Charlie I've had a couple of 'semantics wrestling' matches with EarthX. This whole 'lead-acid equivalency' thing is smoke and mirrors . . . at least as far as aircraft are concerned . . . where STARTING an engine is NOT the defining factor for battery sizing. They asked me to participate in the development of an EarthX 'application' document wherein the company would suggest one of their products as suited for popular models of aircraft. I attempt to explain that such a document was not only fraught with potential for error, it opened them up for a lawsuit should some hapless pilot run out of battery snort after having replaced the stock SVLA battery based on EarthX lead-acid equivalency claims. I have an EarthX battery sample that I intend to test on my minivan. But I need a data acquisition system that Paul and I have under development. It will gather fine resolution data for battery performance for long periods of time. I'll get a month of data on the as-installed, soggy battery. Then on the EarthX battery, then on a new battery of the size recommended for the car. I'll do cap-checks on all three test articles as well. But in any case, be aware of the need for knowing USEABLE CAPACITY of any battery you install irrespective of brand or chemistry. Understand further that many of the folks out there hawking light weight super-batteries to the OBAM aviation DO NOT appear to understand the unique requirements for integrating a battery onto an airplane. 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.