On Feb 19, 7:42*pm, Jim Yanik wrote:
"William Sommerwerck" wrote :

Just to add, it's sometimes cheaper to buy a different make of
battery that may be on offer and rob it of its cells to fix another.

This is not generally a good idea. Replacing the bad cells in one
battery with new, good cells, is likely to cause cell reversal during
operation.

You also have OLD cells with lots of charge cycles mixed with new cells,and
the old cells will fail sooner.

You should generally replace all the cells.

Agreed.

It's also useful to have some way of measuring each cell's capacity
while discharging it, so you can roughly match the cells' capacities.

agreed.

--
Jim Yanik
jyanik
at
localnet
dot com

You can solder to the tabs or to the remains of the tabs where you
have pulled them off. Scratch the metal before you solder to get them
to take the solder. Use flux also. Replace all batteries, using NMH
rather than NiCad, as they have larger capacity. they are sub-C, I
have had to replace my wife's roomba batteries, so know first-hand