Reikes wrote: > I decided to check voltage one night last week after cart had been > charging for approx 8hrs & heard quiet but audible sizzling / boiling > sound from both banks of batteries.
"Both banks"? The pack in a GEM is located under the seat in a single cluster, and you said you installed 6 group31s, which should fit neatly where the OEM pack was; I'm not at all sure what you mean when you refer to multiple banks of batteries? > Voltages varied but highest was 16.2V!! The profile finished about > 30 minutes later so I definitely caught the end of acceptance charge > but still scares me. Actually this wasn't the end of "acceptance charge";^> The charge profile you are using is an IUI type, and "acceptance" or "absorption" refers to the constant voltage step (the "U" in "IUI"). You observed the battery voltages shortly before the charge terminated, and so the profile was in the final constant current step. > $1600 of brand new Lifeline AGM's crying out > for help should make any geek reading this forum squirm a bit :) I don't mean to single you out, but since this seems to be quite a common situation I think it bears mentioning that one really ought to determine what batteries are compatible with the charger they plan to use *before* buying an expensive new pack. The charger in a GEM car contains charge profiles optimized for the specific battery options GEM offered, and they did not offer an AGM option. > Possibly sizzles of contentment? Next morning voltages had all settled > within 13.6-13.8V. Two variables make me wonder: > 1. Outside air temp was 45-50F. Perhaps sensor picked that up & drove > acceptance voltage? The sensor should be attached to one of the battery posts. The charger will indeed adjust the acceptance voltage up or down based on the measured battery temperature. > 2. The multimeter I'm using is questionable. It's digital and of > reasonable quality (~$40 range) but had another meter run me around > in circles a few years back... I suspect your voltages are in the right ballpark, but something to watch for with inexpensive DMMs is that while they may be reasonably accurate at room temperature, they could have significant error when used in cold or hot environments. Cheers, Roger. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
