Comment Most batteries have cell management done wrong (Score 1) 143
Unfortunately, most multi-cell batteries do cell management wrong and are unable to isolate dead cells. A typical "dead" battery has one bad cell, with other cells having more than another lifetime of reasonable performance ahead of them. Most laptop and power tool batteries will work completely satisfactorily if you merely break up the cells and apply proper cell and charge management that is able to extract charge from and impart charge to each cell independent of other cells.
Most "dead" batteries that people throw away are good - except for one cell.