Remote battery mount v Voltage drop

[TRobbo]

I was thinking of building an semi sealed compartment under the floor around the centre of the vehicle to mount the vehicles batteries. Access likely by tilting rear seat and then a cover in floor. What sort of voltage drop would occur over that distance and can anyone see any probs with this?

[chimpboy]

The only problems are probably already obvious to you - you need to run some really fat cable to the battery, and you need to protect it from being bashed up or drowned. Also avoid having battery fumes venting into your cabin.

Other than that, no biggie.

Lots of utes have had their batteries moved to behind the cabin. My old Jag XJ-S had the battery in the boot as there was just too much V12 in the engine bay; that had a heavy cable running through the transmission tunnel to the front of the car.

The main thing that needs a heavy wire is the starter motor anyway, so you would probably go: +12V on battery -> starter motor -> alternator with the fat cable.

Jason

[TRobbo]

Too good Jason - you seem to be our resident outerlimits elec guru. Knew about venting and protection (the storage box would provide complete frontal and underneath protection with the rear being partially open to allow for venting), but the dumb q is water protection - is that for the battery or to prevent water ingress and subsequent corrosion of the 12 volt cable?

[drivesafe]

Hi TRobbo, it usually works out to be a much bigger job, but take the time and always run your cables where ever possible, inside the vehicle.

You can usually follow the existing vehicle wiring.

This is not only a safer set up but it will also meet the suggestion put forward by chimpboy.

Cheers.