Charging battery in camper trailer

[danman-gq]

Hi

I have a deep cycle battery on the camper trailer (for fridge) and want to charge / top up while travelling to the campsite destination.
How can i do this simply?
Someone did tell me to run a single wire from car to battery but didnt elaborate. Can anyone advise best / simplest way to charge while driving only. Once there the fridge will run from deep cycle battery only and cabling will be disconnected from car.

Any advice would be appreciated

[MART]

I used to run it through a seven pin trailer plug , 5 pins for trailer lights and 2 pins , one negative and one positive to charge battery. I used to pull the power of the auxillary side of isolater , diode type and switch it through a relay to charge battery. The relay had a switch in series to act as a isolator switch and was normally left on. The relay switching power was fed fron ignition circuit , so this meant battery was charged only when car was running , hope this helps as there are many ways to skin a cat , Cheers Paul.

P.S. Add a fuse in line to give protection against short circuit , or dead short.

[-Scott-]

The seven pins in a seven pin trailer plug are all assigned to specific functions. There's a few links in this forum to charts showing what's what.

Using a different combination may mean you have trouble with the lights on a borrowed trailer, or somebody else may have trouble when they attempt to tow your trailer. Worst case may be a shorted battery. Fortunately, such a short is unlikely to last long.

Personally, I would install an anderson plug - they come in a number of current ratings, the smallest version should be sufficient.

Wiring from car battery to trailer battery and back again can easily exceed 14m. I suggest using the largest wire you can terminate (crimp/put lugs on), to minimise resistive losses. This won't make much difference when your trailer battery is fully charged. When it's half flat, it will want to draw more current to recharge - thinner wiring effectively limits the charge rate, so the trailer battery will take longer to fully charge.

Good luck,

Scott

[danman-gq]

is it as simple as running positive to positive and negative to negative terminals to provide charge while driving, or would this cause other problems and issues?

[drivesafe]

Hi danman-gq, see if this will help, just substitute the SC80 for what ever dual battery controller you have.

Cheers.