Forum Discussion

4x4ord's avatar
4x4ord
Explorer III
Mar 19, 2020

Cut off switch with solar panels

I bought 4x 100 watt solar panels and a Renogy Rover MPPT charge controller. The Rover manual states: NEVER connect the solar panel array to the controller without a battery. Battery must be
connected first.

So I guess I have to remember to remove the batteries I need to disconnect the panels first. I find this interesting because my father has been pulling his batteries out of his 5ver for winter storage for years and I'm sure he doesn't disconnect his solar panel to controller. Maybe the wattage of his panels isn't enough to fry the controler. I think this sounds like an accident waiting to happen. At some point someone will disconnect the battery to replace it or clean the posts and not know to disconnect the controller first. I guess it would help some to install a switch on the positive wire from panels to controller?


Edit: I was wrong. He pulls a fuse on the front of his controller when he removes his batteries.

16 Replies

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  • work2much's avatar
    work2much
    Explorer
    Mar 19, 2020
    Yes, most controllers need to have 12v power to turn themselves on and running solar panels to them without the battery connected isn't advised. On our Victron it emits the high voltage alarm to remind me.

    It is a good idea to circuit protect the wiring anyway so I installed a blue sea circuit breaker between the roof combiner box and the solar charger to protect the cabling anyway. It is mounted inside the camper on our system as I like to turn off the solar once the LFP batteries are full or close to full. LFP doesn't benefit from a small trickle charge when full or close to full. This could be mounted anywhere between the panels and the controller.


    Click For Full-Size Image.

    On the battery side I also installed a circuit breaker between the solar charger and the battery to protect that cable as well and to work on the solar charger if needs to be deenergized but I wish to keep the rest of the system live.


    Click For Full-Size Image.
  • Old_Days's avatar
    Old_Days
    Explorer II
    Mar 19, 2020
    Can someone post a link of a good switch to shut off power from 270 watts of solar to the controller. Thank you.
  • Lwiddis's avatar
    Lwiddis
    Explorer II
    Mar 19, 2020
    I use a couple of tarps over my three panels then disconnect just to be safe. I don't want a busted controller. It was heck to get it installed in my pass thru storage comparment.
  • ppine's avatar
    ppine
    Explorer II
    Mar 19, 2020
    You need a disconnect between your batteries and your controller. Put it on a board with your controller.
  • 2oldman's avatar
    2oldman
    Explorer II
    Mar 19, 2020
    4x4ord wrote:
    Maybe the wattage of his panels isn't enough to fry the controler
    Maybe he's under cover..?
  • Ductape's avatar
    Ductape
    Explorer
    Mar 19, 2020
    That’s what most installers do. Might be a good idea to post a label by the battery terminals reminding techs to turn of solar switch -and where it is located- if you’re anticipating someone other than yourself working on it.

    I turn my solar off before putting the coach in for repairs just in case.

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