Cable Size to charge Camper Battery

Andrew.
For a balance between safety and satisfactory charging a total resistance of about .1ohm is best, this includes the resistance of all components, ie the wire, the relay, the cct breaker, any plugs or connections. The reason it is best not to use very heavy wire is to limit the current to a managable amount if you get a short due to a wire being pinched in the tow bar or coupling. To establish the best wire size you first must determine the length and then calculate the wire size. You do not reqiure any fancy black boxes to make the system work. Eric.

gday kidz.
since we mounted the weaco in the camper we run 6mmx2 no problems at all.
reason for 6mm x2 im to bloody miserable to bye bigger cable .lolol
6mm cable not even $1 per metre

Hey, have you got a new camper trailer or is the the one you had........
Karen

Hi Big Kidz,

The bigger the cable the better as you will get a voltage drop by the time the current finally gets to your camper trailer. As an example, a 0.1 ohm total circuit resistance will result in a voltage drop of 1.5 volts at 15 amps (typical recharge current draw). An alternator nominally puts out ~13.8V, so you are now down to 12.3V at the van battery. This will never fully recharge your battery.

As you mentioned, an Arrid Twin charge boosts the voltage back up to ~13.8V and enables a 100% recharge of the van battery. But it will also take some time as deep cycle batteries recharge relatively slowly.

Also, you should ALWAYS fuse any cable, no matter what size it is, as close to the (vehicle) battery as possible AND at the van battery end as well. The reason for the "double fuse" is that if the cable is pinched at say the drawbar, power can come from either battery and potentially start a fire. If you use a small cable to limit current draw, all you are doing is using that cable as the fuse!

Personally, I run a 3 stage "smart" charger on my van battery and simply use 10mm2 cables from my Patrol to keep my van battery ~80% charged while away from 240V. But if you are away from 240V for extended time periods, an Arrid twin charge (if on the move daily) or solar (extended bush stays) is the way to go IMHO.

Cheers

Captain

Hi Big Kidz,

Like Captain I use a 3 stage charger for my deep cycle camper trailer battery and a solar panel to top up,

As it is a deep cycle I don't even bother to try to keep it charged via the car system when on the move. Don't want to complicate life too much and set up with the Arrid gear.

Rely on 240 and the 3 stage charger or the solar panel when camped.

I use gas fridge so no large draws.

Cheers

Magnus

Hi Big Kidz
I've run a 6mm cable through an Anderson plug. I get 13.5v at the battery in the camper. It's been like that for 2 years and I've never had a problem or a flat battery but I'm not running a fridge of it though I believe I could if I wanted to. I just run lights and stuff.

See Ya
PatC