Run earth cable, or body earth? For power outlets

[mike_nofx]

I've just installed a 2nd battery and want to run some power cables to the rear of the wagon to run a fridge.

Should I run an earth/neg cable from the 2nd battery all the way to the rear power outlet?

Or is it ok to just run a positive cable only and just a good solid earth from the outlet directly to the body?

Thanks
mike

[-Scott-]

I think I would earth to the body - and I think that's what I did in my Paj, about 8 years ago.

For a fridge outlet, I can't imagine why you would need to run a dedicated negative cable.

[Black Bull]

Depends on what current draw you plan to have. for accessories like lights and fridges etc, body earth is fine, just make sure contacts are clean metal, I usually spray them with battery terminal spray to stop corrosion.

[drivesafe]

Hi Mike, while things like low wattage camp lights can be run via a body/chassis earth return but medium current devices like compressor fridges should have twin cable power supplies particularly when some brands play up if there is the slightest voltage drop.

While you can USUALLY get a good earth via body/chassis earth, if you don’t, it’s a pain to find and fix so it’s just easier to run a separate earth.

You are far better off running 6mm AUTO twin cable from your battery ( cranking or auxiliary depending on your set up ) via a 30 amp circuit breaker at the battery and a 20 amp fuse at the power socket end.

Note most devices that use the cigarette type power sockets usually have a fuse in their plug, but not all devices do. Many inverters do not and these can pull some high loads so the 20 amp fuse is just a safe way to set up.