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Mote's avatar
Mote
Explorer
Sep 09, 2014

Issues with solar panel

We bought the camper used a couple of years ago. It has a solar panel on the top that is wired to a controller under the sink and then two leads going to the battery.
I bought a new battery a couple of months ago. When I installed it I didn't hook up the two wire to the solar panel. We used the camper a few times an everything worked great.
A couple weeks ago I decided to hook up the solar panel wires again. We went out to start getting ready for a trip and everything was dead. I forgot to pull the disconnect switch. Well, I plugged the camper into the barn to charge it back up. After a day I went out and was going to use the electric jacks to raise the camper to mow under it. The jacks wouldn't work. Just clicked like the battery was dead.
I made sure the disconnect switch was on. Still no luck. I decided to unhook the solar panel wires from the battery since it worked before that. Withing a few minutes everything was working again like it should.
Why would having the solar panel hooked up to the battery cause it to not charge?

9 Replies

  • Charge to full charge w/ controller wires disconnected.
    Then in the dark, touch the controller wires to the battery,....if you see any kind of sparking, leave solar disconnected till it is checked out,........most likely requiring controller replace.
  • Thanks for the suggestions. when I get home tonight I'll take a look at all the wiring connections.
    I don't think the battery connections are hooked up backwards as I have the black wire on the positive and the white wire on the negative terminals of the battery. Plus, it did work correctly when we first bought the camper last summer.
  • Some panels have their own diodes so they don't suck battery power at night. If not, in that case they are connected to a controller that has that diode so it keeps the battery free from the panel at night.

    Say you have such a diode-free panel and a controller that has lost its.

    Sort of a far-out possibility, but you did ask for anything that might be it.
  • Hi,

    Grab a meter and check the output of the panels. Check the output from the controller. Tighten all connections. Don't trust the color coding--find out which wire is the positive coming from the controller.

    Your new battery is probably going to have some reduced capacity after being left flat dead for some time.
  • You are dealing with clandestine BAD CONNECTIONS where the panel connects to the system. Like a rotten oak, everything looks peachy dandy from the outside until the tree falls on you. Dig into ALL of the connections at that site and get them in first class condition. Has the controller magically turned into a heater? Connect and put your hand on it 5 minutes after reconnection? Does it feel like a griddle ready for pancake batter? Do this test after you dig through and repair all those connections. Do the battery too.
  • Poor battery connection. Panel itself should have no effect against the converter power.

    Verify battery voltage is about 13.6 on the actual battery terminals.

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