On Mon, 3 Aug 2020 18:33:17 +0100, G r o g wrote:

The battery has to be removed from the tank to charge it, it's 8 AA size
cells in a plastice shrink wrap ...

Standard batteries, Good.

... with a 2 pin Molex type connector

Probaly the standard RC battery pack connector. Good.


The battery pack is a fairly tight fit into the tank so I'm going to
need an almost direct replacement.

Would the be room for 8 x AA's in a battery box in say 2 x 4 layout?

They may be nicad batteries, given the age of it which adds to the
problem.

Only that they are probably dead and beyond recovery. As far as
charging is concerned NiMH is the same as NiCd so you could try a
standard 9.6 V RC charger on the pack. Zapping each cell with a
briefly directly connected fresh PP3 might blow the "wiskers" in each
cell and help bring them back but if they have bee sat for years I
wouldn't hold out much hope.

A quick look on eBay showed 2 x 4 wrapped AA NiMH packs with the
standard RC power connector for just over a tenner from China.

--
Cheers
Dave.