newshound wrote:
Cells are sometimes very tight, the usual solution is violence. In this
case, you don't need sealing at the top of the turret, I'd suggest
drilling a couple of holes that would line up with the axis of each cell
and using these to press them out. The cells will presumably be bridged
by a conductor strip, so they will need to be pressed out together.

It may also be that they're glued in. A little heat (hairdryer?) may loosen
the glue.

If there are 10 cells, that suggests NiMH - or is it old enough to be NiCd?
In principle there's no reason why you couldn't go for more capacious cells,
although your charger may not charge them correctly (a completely dumb
charger is likely to be fine, a 'smart' charger that isn't very smart may
terminate the charge too early)

Theo