Dueling battery arrays

[PTech]

I have two 170W collector on my RV and on a trailer. Both have their own controller and separate battery arrays.
The batteries in the RV are 2 Trojan 105s. In the trailer are two 125 pound 6V batteries.
How can I use the batteries in the trailer for the RV.

[SunEagle]

Hello PTech and welcome to Solar Panel Talk

You would need to wire in some type of transfer switch that would connect the RV loads to either battery system.

A manual transfer is probably cheaper and relatively easy to install if you understand electrical wiring and 12V system requirements.

[PTech]

Either or then?
Could the larger bank charge up the lesser batteries?
Maybe isolator with the load on middle post?

[Mike90250]

Only use the solar to charge batteries, When you use a battery to charge another battery, you can get
really high amps that can damage both batteries. Think about car jumper cables getting hot.

[SunEagle]

Either or then?
Could the larger bank charge up the lesser batteries?
Maybe isolator with the load on middle post?

You really should not use one battery system to charge another. It really does not work. As I stated before if you want to use two different battery banks to run your RV loads then you will need some type of transfer switch to connect those loads to a specific battery bank.

I never said it would be cheap or easy but it can be done.