Second leisure battery

[Pwood811]

I have a ex rac van which has the factory fitted leisure battery. It’s an agm battery which was identical to the starter battery until I replaced it with a bigger one as it was failing to start intermittently. Obviously the old starter battery didn’t have enough power to start the van but would it be any use wiring under the bench seat to upgrade to capacity on the leisure side without too much cost? Planning on upgrading to a dc-dc charger soon. The van is a work van and will be used occasionally with the family. I’m buying a van king so may get away for the odd night or just for day use.

 

[rod_vw]

It's not a good idea to connect two batteries in parallel unless they are more or less identical in design and age/condition.