When installing Solar panels can I reuse the existing DC battery charging cables?

[BeerBrewer]

I'm thinking about adding a 200-300 Watt solar power setup to my Transcend 26RLS and I've got a few questions for those you that have done it.

If I install panels on the roof I can easily get to the fuse panel and AC to DC Power Converter in the trailer. They are both installed at the bottom of a cabinet that contains the TV, next to the rear door. The cabinet has plenty of room to install the solar control panel as well. Unfortunately I don't how easy it will be to run the solar power cables to the batteries located in the front of the trailer, just behind the hitch. So I'm wondering if I can use the existing cables that run between the existing Power Converter the batteries. Has anyone done that or is it normally necessary to run new wires? I don't know what the wire gauge is, but I could easily figure it out by crawling around the trailer with a wire gauge tool.

[BB&LAB]

You will need to run new wires from the panels to the charge controller. Before you purchase wire, you might consider identifying what charge controller you want and read the specs on the largest wire gauge it can accept and then purchase wire gauge of that gauge. Larger is indeed best when it comes to wire gauge in most cases to minimize voltage drop over the length of the wire.

[BeerBrewer]

After rereading my post I though that I should clarify what I meant by reusing the cables between the AC to DC power converter. I was hoping that I could have the solar system and AC to DC power converter share those same wires provided that they are a heavy enough gauge. Rather than running a new pair of wires back to the batteries.

[jh.xsnrg]

After rereading my post I though that I should clarify what I meant by reusing the cables between the AC to DC power converter. I was hoping that I could have the solar system and AC to DC power converter share those same wires provided that they are a heavy enough gauge. Rather than running a new pair of wires back to the batteries.

It really depends on the output of your converter. Look it up to be sure, but if the converter is capable of probably 40A or more, and you are only looking at 300W of solar panels, you can likely use the same wire run. 300w/13v = 23A. If your plan is to not use the converter, or not at the same time anyway, go for it. Do not run both though, as you will be over the limit for the wire. Fuse the run close to the charge controller, and size the fuse for the wire.

All that being said, the wire run from the converter is probably the very minimum size they could use, so if you are going to run amperage close to the converter's output, a better wire would be more efficient.

Jim

[jmbopp]

I'm using 200W of portable panels but the MPPT controller is mounted in the pass-through. It's a short run but I added a 6ga ground wire and tied to the hot side of the disconnect switch using the factory wire.