---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 05/24/14: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:02 AM - alternate batteries (GLEN MATEJCEK) 2. 10:22 AM - Re: alternate batteries (Charlie England) ________________________________ Message 1 _____________________________________ Time: 10:02:41 AM PST US Subject: AeroElectric-List: alternate batteries From: GLEN MATEJCEK > > I happened to be exploring some alternate battery battery options on the > 'net just yesterday, when something interesting popped out at me. Only one > referenced being a replacement for portable jump start units, and was > marketed under the Schumacher label. Does anyone know if there is some > difference in these batteries that might make them more appropriate for > engine cranking service, or is it all just advertising? ________________________________ Message 2 _____________________________________ Time: 10:22:32 AM PST US From: Charlie England Subject: Re: AeroElectric-List: alternate batteries On 5/24/2014 12:01 PM, GLEN MATEJCEK wrote: > > I happened to be exploring some alternate battery battery options > on the 'net just yesterday, when something interesting popped out > at me. Only one referenced being a replacement for portable jump > start units, and was marketed under the Schumacher label. Does > anyone know if there is some difference in these batteries that > might make them more appropriate for engine cranking service, or > is it all just advertising? > > Look at internal impedance/resistance numbers. Easy to find for PC680; sometimes harder to find for brand x. Comparing batteries with the same ampere-hour ratings, batteries intended for relatively low current, long term discharge will have higher internal impedance than batteries intended for starting. Bob alluded to this in a recent post about a new battery he tested, that would last almost 'forever' running avionics, but couldn't supply enough power to start an engine. With the typical brand x SLA batteries I've seen over the last few years, up-sizing the AH rating by a few points (18 AH to 22AH, for example) gets the internal resistance low enough to match the higher priced PC680's starting ability. Going from 18 to 22 AH doesn't typically increase the size, at least not enough to matter. A lot of the brand x 18AH batteries are slightly smaller than a PC680. FWIW, Charlie ------------------------------------------------------------------------------------- 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.