@exador23
There is a strange contradiction about the best way to use Li cells.
Rule 1 keep cells balanced
Rule 2 prefer to keep voltage range of cells within 20 to 80% to extend lifespan.

Unfortunately most balancers work at max voltage, which you try to avoid. Therefore I advise and started using active balancing circuits that pump power from the higher cell to their lower neighbour. They work at every voltage.

The (cheap) circuits you buy, for example on ebay, are 1 Amp max. Although that is not much it gets the work done over time with cells that are not too different.

Cells that got bad will lose capacity, they are full earlier on in the charging process and race up when current isn't taken back because total voltage/avg cell voltage hasn't reached max. Maybe that's the problem you face...

#Lithium #batteries #CellBalancing