On 03/07/2014 12:43 AM, EVDL Administrator wrote: > My poorly-informed view of bottom balancing is that I'd better not try it. I > get the impression that it takes more time and attention than I care to give > to charging batteries. Not that I want to sound cavalier or anything, but > dang it, I have too many other things I like doing! Without a smart BMS > looking after my battery, I'd probably murder it.
Bottom balancing--in general--in a one shot deal. It's a pain in the butt to set the pack up. You trying to make sure all the cells are depleted to the exact same level. The idea is that once they are, they will charge and discharge at the same rate and stay together. By subsequently avoiding the very top and bottom of the charge curve you compensate for any slight differences. Of course it assumes that the internal resistance of these cells is close enough that you won't get substantial cell drift. You should check the cells on occasion to make sure none have gone walkabout but the difficult part of bottom balancing is just done once. The purported advantage of bottom balancing--in addition to a simple or no BMS--is that if you drive the pack too low all your cells will run out of juice at the same time. It becomes very obvious to you that the pack is dead and none of the cells has enough power left in them to do any damage to their neighbors. --Rick _______________________________________________ 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)
