---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 05/08/20: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:04 PM - Re: Re: DC clamp meter (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 07:04:16 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: DC clamp meter >Does this sound like a reasonable way to do a meaningful capacity >check? It does to me, but what the heck may I be missing? Seems >like the hardest thing to do will be rigging up the resistive dummy >load (open for ideas) so I can consistently do the load test per >battery year to year.\ Okay, got a tighter box around your goal. Probably doesn't need to be that complicated. You know your endurance loads to a reasonable degree of accuracy. The really cool thing about Li batteries is their very FLAT discharge curve as a consequence of low internal resistance. This means that energy delivered to the terminals is relatively constant irrespective of load. So consider getting some of these. https://tinyurl.com/ydg62u2r an order of 5 pcs is about 8 bux delivered to your door. Mount 4 of these to a chunk of aluminum say 6 x 6 inches or so. .06 or more thick. Space them out over the surface. Hook all four in parallel to make a robust, 1.0 ohm resistor. This resistor connected to one of your batteries will discharge right at 12.5 amps. Time the interval to discharge limit with this load. Since you have quite a bit of time on these batteries, you don't have an as-new benchmark but you now have as-is benchmark. Maybe the a.h. number isn't really that useful. Rather, it's time to trip the discharge limiter. That's pretty close to your as-is endurance value. When that number is below design goals, change the battery. 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.