Need Help...I have a Solar Panel

[mecicon]

A good friend gave me a solar panel that measures 39" x 48" in it's previous life the panel powered a "parking lot light".

My goal is to use the panel to charge my battery while boondocking thus taking some of the load off the generator.

Question: Where/how do I connect the panel? Do I connect to the inverter?

[Bill]

Mark -

We need to know the number of watts the panel produces, as well as the number of volts. If the panel has a label, it should tell you. Or at least it should give a mfr name and part number. Dimensions are only vaguely useful. Please tell us everything you can about the panel. Pictures of labels could help.

Incidentally, you almost certainly don't have an inverter, and if you do, you don't connect a solar panel to it. You are referring, I think, to the converter. You don't really connect to the converter, either. You connect the panel to the battery, through a charge controller. The experts on this forum can tell you what you need to know, but need to know everything about the panel.

Bill

[mecicon]

There are NO labels on the panel I'm shooting in the dark.

Good thing I got this panel for free because that might be what its worth. I'll see if I can garner any additional information.

[Bill]

A little Googling shows that solar panels tend to come in standard physical sizes.
39 x 77 = 300 watts
39 x 65 = 250 watts
39 x 48 = ?
This last doesn't appear to be a standard size, but scaling down from the others suggests that it would be about 180 watts.

If you can set the panel in the sun, and measure the output voltage with a meter, that will be the next piece of info we need.

Bill

[BrucePerens]

This should work with any single panel and lots of multiple ones, because it takes 50 volts and 20 amps, and costs only $18, and it has a readout that tells you if it's working.

Install it where it's dry (I have my charge controller, not this model, under the street-side couch with wires running out a hole in the floor). Run wires up the street-side lift arm to get to the panel, and to the battery after the fuse (so it's protected and so are you).

Borrow a volt-ohm meter if you don't have one.

Measure the voltage coming out of the panel on a bright sunny day. That is the open circuit voltage, and it tells you which is the + wire and which is the - (minus) wire. Mark them.

Then measure the voltage between either wire and the metal frame of the panel. That will tell you if the panel has ground connected to one wire or not. If there is a voltage between the + wire and the frame, the panel has negative ground. If it has no voltage between either wire and the frame, the frame is not grounded, which is fine.

If it has voltage between the - wire and the frame, it has positive ground and you will have to be careful to isolate the frame from the skin of the Trailmanor when mounting it, because the Trailmanor has negative ground. But this is unusual so it probably won't happen.

Get back to us if the instructions for the charge controller are incomprehensible.

Shorting the battery out can make things red hot if there's no fuse. Take off jewelry or use a glove, you don't want to experience a red-hot wedding ring.