Normally it doesn't as people just figure they will not bother to get the full life out of them. But if someone were to want to extend the life of a set of SLA's it still actually makes some sense if the PRICE is low enough.Don Harmon wrote:I am truly confused. Since when did cell balancing apply to SLA Battery Packs ?
I charge in parallel, so charge balancing is not an issue, but when in runtime the differences between cell capacity means that one cell will always be the weakest and wear out the fastest. (because it will end at a lower voltage than the others every time)
SLA is cheap... after a thousand miles the easiest thing is just to replace the weakest cell, but if you had balanced as you rode then you might get to two thousand before you would replace all the cells at once.
The difference is really one of "replace all at once" or "replace one at a time". But when you do it one at a time (allowing the "runt" to die a slow death) you actually get fewer total Watt Hours out of the cell compared to balancing.
It's totally different than something like NiCads that don't wear out at all by having low voltage... you have to remember that SLA is a lot like LiFePO4 in that low voltage really wears them out.
SLA could use non-resistive runtime balancing... but is it cost effective?