On Fri, Jun 17, 2011 at 9:27 AM, RussellMc wrote: > Many of the answers from the prior LiIon charging threads apply. > > Current needs to be limited, of course, to the maximum allowed by the > batteries used. > > Zeners are nowhere precise enough for balancing. > A reference voltage controlled clamp (super zener) would be better. > eg a TL431, opamp sectopn, clamp transisto and "glue" per cell. Small > % of battery cost. > > If running at 4.1V you MAY get close enough to allowable termination > voltage at some temperatures that charging termination is needed. > (Cells charged above a certain voltage need to have charging stopped > as charge current falls to some fraction of Ichgmax. > Lowering Vcellmax to 4.0V would probably [tm] eliminate the need for this= .. > > You can get multi-cell balancing ICs BUT the above is easy, cheapish > and would work OK. > > An easy termination system would be when all cell clamps are set to > say 4.1V and all are clamped. With only 1 or 2 clamped charging > continues. > > > > Russell > > Could you draw a simple schematic on how this "clamp" works? I'm not really understanding it. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .