Solar Switch ?

[stinespool]

Hi all, I installed a 175 watt solar panel on the roof and was wondering: We have the motor home plugged in all the time. Would it be a good idea to install a cut off switch from the solar to the battery's while onshore power? I get a lot or good info on iRV2! Thanks!

[astrocamper]

I use a breaker disconnect between the panels and the MPPT controller. I have a disconnect switch between the MPPT controller and the battery bus bars. I like to be able to disconnect circuits if I have to change out the controller or work on the 12 volt stuff connected to the bus bars.

I have my Progressive Dynamics charger a switch so I can have my trailer plugged in but not charger my batteries. I let my solar system keep the batteries charged unless my panels are covered with snow.

[Winterbagoal]

It depends. If you're using a (good quality) charge controller between the panel and the batteries, it will figure our whether it needs to send current to them, or not. So in that case it doesn't matter if you're plugged in and adding solar to help out the overall charging situation. If your converter/inverter/charger is decent also, it will also see the battery SoC and adjust accordingly.

[twinboat]

You will not overcharge your batteries, leaving the solar on, as long as you have a controller.

Just like your engine alternator, converter/charger or Inverter/charger, they have voltage regulators. The regulators control the volts and amps going to the batteries.

If the batteries are fully charged, only the source with the slightly more voltage set point will keep the batteries at float levels.

[rarebear.nm]

If your solar controller is a good unit, it will not be a problem. On my 5th I turned off the breakers to my converter when the solar was installed and have never needed to turn them back on. But I have 1050 watts on the roof. 100% of our 12 volt power has come from solar for four years now. Twinboat has it spot on.

If you don't have a breaker or fuse between the panel(s) and controller you add one. Likewise between batteries and the solar controller. Remember that breakers/fuses are there to protect the wires from an overload (high temp) condition, not any devices.

A little side note. Always turn off the switch/breaker between the panel(s) and the controller before you break the connection between the batteries and solar controller. At least that's the warning for my Morningstar MPPT controller. And reverse for reconnecting power.

[Persistent]

Originally Posted by Winterbagoal

It depends. If you're using a (good quality) charge controller between the panel and the batteries, it will figure our whether it needs to send current to them, or not. So in that case it doesn't matter if you're plugged in and adding solar to help out the overall charging situation. If your converter/inverter/charger is decent also, it will also see the battery SoC and adjust accordingly.

This is good advice. Multiple sources of DC 12 volt power can be connected together without harm.

[stinespool]

Thanks to all! I did add a disconnect between the panels and controller. I will add fuses as well. It's up and running and working well!

[rarebear.nm]

Glad to hear the update!