720i balancing problem

[pinkpanda3310]

I don't have that charger, I have a cheap chinese one. It is not accurate when balancing and over time I beleive it has gotten slightly worse. Some packs it can balance to with in 0.02v, these are usually packs with less cycles, charged at less amps and don't require a whole lot of balancing to start with.

Other more dodgey packs I have (reclaimed A123's from dewalt battery packs) get to with in 0.05 - 0.07v and will not balance. I am not able to measure the resistance of the cells but I suspect that is what is screwing around with the charger.

That's how I understand it anyway. The different resistance causes the cells to relax to different voltages, when a cell will not hold 4.19 - 4.20v and others will, the charger/balancer is constantly working.