Battery cable size

best bet is to use welding cable. far less power drop.
but.... you must protect the cable. as the housing is very soft and can be cut way easyer than you can belive.

all conections, us gold plated items ( see the car stereo sites for these).

buy a better grade and larger than you think you will need power inverter. ( will last far longer, with no "problems").

and double the number of storage batteries ( four of them min . aka 12 volt).

i know sounds over kill, but one should never have a supplyed power drop this way.

is possable check and maybe replace the coach wiring as it may be sub-standard
(aka: cheap, wrong style/ kind of wire) as the manf do cut corners.

There is absolutely no benefit to going larger than the main leads, and even going a size smaller would not hurt performance. It's only a foot long or so. Yes, the main leads should be on opposite batteries.

I uses either Vertex or Ancor wire. This wire is temperature rated as well as being tinned so that over time it will no oxidize and loose capacity.

If you are going to run a decent sized inverter, you should go with the same gauge that your inverter requires. As stated, make the jumpers the same length and connect trailer load to one battery and ground to the other. I have a 2000 watt inverter and built my own 4/0 cables using welding cable purchased from Amazon. The welding cable bends very well.

Do we have any idea what kind of amperage we're talking about?

Thanks for all the responses, I ordered #2 red and black cables. Now the fun begins trying to bend this stuff.

Same as the trailer or larger. Welding cable would work fine as long as you can make solid connections.

Happy Camping!

I used # 4 batt. cable available by the foot from NAPA. $12 for 2 10" cables plus ends which I soldered on or buy solder pellets from NAPA also, it's easier.

When you hook up the trailer connections to the batteries connect the positive to one battery and ground to other battery, it utilizes the batteries power better. Search internet about it.

The same size and what comes out of the trailer and hooks to the battery now. Wire them as time2roll suggested so they will charge and discharge evenly. This will make the advice of 2oldman incorrect when wired this way.

Don & Barb Bogue wrote:
Bigger is better, go with the Welding cable...

Sure, 4/0 should do it.