Location of Battery(s)

Hab battery under the offside settee, (I think).

They are within the confines of the vehicle.

If vehicle is available  a search may help.

Vehicle batteries are usually within in the engine bay, trace the big cable from the starter motor.

As for habitation again searching for and tracing of supply cable that feeds the control/distribution panel will find it.

If it's like ours, and it almost certainly is, the vehicle battery is in a well under the passenger's feet, and the Hab battery is either under the driver's seat, or under the offside bench seat (I can't remember for that year.) This is assuming it's an EK model. (You didn't specify.)

If it's not, the vehicle battery will be in the same place, and the Hab battery is big enough to find quite easily!