Hi guys,

Thanks for all the comments/help, it's much appreciated!

The info I've got on the CAT battery so far is: 48V (possibly 500ah, although that part of the battery sticker has worn off so I googled it against the type, which according to the spec plate is TMHD 455/4), the outer battery box dimensions and the min weight (it doesn't specify a maximum weight). Anderson socket.

For the Crown I've got the outer battery box dims, the min and max battery weight, 48V, 950AH. Anderson socket.

Unfortunately both trucks are well out of the manufacturers warranty. We bought them second hand and the dealer warranty was 12 months on the batteries, they went wrong just after the 12 month period, so we don't have a leg to stand on.