RV House Batteries Trickle Solar Panel

I am currently living in an RV while building a house. I am totally off-grid and have 8 golf cart batteries (880 total ah), three 135 watt solar panels with a Magnum inverter/charger and a back-up generator installed on the RV. The solar system was installed this year. (I received some help with this on this forum.) I plan to add one more 135 watt panel after the holidays.

In addition to the solar system I installed (for running computers, satellite, fans, etc.) there are two golf cart "house" batteries and a small solar panel on the roof. Apparently, this setup, which was on the RV when I purchased it, is for DC only and starts up the generator, runs the overhead lights, is needed constantly for the propane refrigerator and also runs the water pump. There is no controller with this system, just a converter.

Since I have not been running the generator as much, the house batteries are not staying charged with just the solar panel. It is a very small panel so now I'm thinking that solar panel must be under 20 watts (maybe only 10 watts) and it might just be a trickle charge setup for when the RV is not being used. And since the refrigerator is running 24/7 this set up is just not working. I can't find specs on the Dometic frig so not sure how much it draws.

My question: Is it possible to somehow tie the converter to the 8 golf cart batteries I have connected to my new solar system, so I don't have to add another panel just for the house batteries or do I need to keep these two systems separated?

Comments

  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: RV House Batteries Trickle Solar Panel
    iabteri wrote: »
    My question: Is it possible to somehow tie the converter to the 8 golf cart batteries I have connected to my new solar system, so I don't have to add another panel just for the house batteries or do I need to keep these two systems separated?

    Sure it's possible. You just have to disconnect the converter from the house batteries and connect it to the solar batteries.

    Probably the easiest way would be to install a switch:

    http://store.solar-electric.com/basw1300amp.html


    Another way to go would be to run the new PV through a controller like the Morningstar SunSaver Duo, which can charge two battery banks. Connect it to both the house battery and the solar battery, and set the dip switch 90/10 to the house battery. Then it will send 90% of that PV's output to the house battery and 10% to the solar battery. Once the house battery is charged, it will then send all the output to the solar battery.

    http://store.solar-electric.com/modubachco25.html


    You didn't mention what charge controller you have on your solar now. You might be better off adding the 4th PV to the array, and then replacing your current charge controller with one that can do two battery banks.
  • iabteri
    iabteri Solar Expert Posts: 45 ✭✭
    Re: RV House Batteries Trickle Solar Panel

    I quickly shifted gears on this one and am in the process of installing another dedicated panel for the house batteries. Just too complicated to try to tie them together.

    Come to find out, that solar panel on the roof was not feeding into the house batteries after all, it was feeding into the engine battery!

    So, no wonder the house batteries aren't getting any charge.

    But thank you for your response.