12v outlet

Gary you need to run a pair (2) of wires directly from the battery terminals with a suitable 25 amp fuse to the camper. The wires need to be a minimum of 6mm² copper conductor size. A 50amp Anderson plug $20.00 (for both sides) is the recommended and usual plug and socket between the vehicle and the camper.

Normally your camper will be wired for 12vDC lights etc either from an internal battery or from the vehicle through your trailer plug.

Cigarette lighter plugs should never be used for more than 2.0 amps
Over 2.0 amps the Hella type 16mm DIN plug are the preferred option.

I would'nt hook up the "hot wire" to a camper or ANY trailer without a dual battery system. Which also needs to have a suitable battery isolator.
Please tell me you have this already?
I prefer to use two pin plugs, known as "low voltage" or caravan plugs. They look a bit like normal household appliance plugs, but the pins are in a "T" so they can only fit into 12v or 24v plugs.

Cheers

Muzz

Gazz. David Au is spot on.

Anderson plugs come in many different sizes and are perfect to run straight from ur second battery in the car(fuses or circuit breakers included of course) to your camper for lights / fridge / inverter for a TV or kettle.

A mate of mine who's an auto sparkie soesn't bother with batteries in his camper, he runs everything on 240v thru an inverter, wired directly from his vehicle thru an anderson plug, but he doesn't use many appliances!
He's from the old school, walk around in the dark, as long as you can find the fridge and the bed, he's not worried about much else.

You can also run it to a battery in the camper if you wish.

Like david Au said, don't skimp on the size of the cable, and cigarette lighter plugs aren't worth two pinches of duck poo.