Newbie Question

[FarmerGreen]

I was looking at the local classifieds and found 4 Solarex panels with a Trace C30 and a Photocomm, Inc meter. Each panel is 36 cells and roughly 22"X49.5". Not sure if that tells me anything about them or not. The info on the panels is very washed out, but I can make out the name Solarex. These were taken off an RV and the seller knows nothing about them. The batteries in the RV were charged from the solar panels and the alternator. Seller says the batteries are no good. I know this is older stuff, at least 12 years. How do I test this stuff and what should I look for? If it matters the panels are still mounted in a long frame end to end. He's asking $400 for everything. This is for my first solar project so any help would be greatly appreciated.

[Bruce S]

I was looking at the local classifieds and found 4 Solarex panels with a Trace C30 and a Photocomm, Inc meter. Each panel is 36 cells and roughly 22"X49.5". Not sure if that tells me anything about them or not. The info on the panels is very washed out, but I can make out the name Solarex. These were taken off an RV and the seller knows nothing about them. The batteries in the RV were charged from the solar panels and the alternator. Seller says the batteries are no good. I know this is older stuff, at least 12 years. How do I test this stuff and what should I look for? If it matters the panels are still mounted in a long frame end to end. He's asking $400 for everything. This is for my first solar project so any help would be greatly appreciated.

FG;
 There are certainly a few things you can do. BUT the final price will really depend on the working parts of the system.
The panels can be be quickly tested to see what they can do, But it'll only be a short test and NOT what the total test, without a plate of some sort of what they should be able to do. You can grab a DMM set it to its highest DC setting and connect it to the output of the panels while they are in the sunshine, and disconnected from any circuits. This will give you the Voltage Open Circuit (Voc).  That will quickly tell you the system's setup.
Much over say 24Vdc and you have a system setup for 24Vdc. Under that and it's 12Vdc.
You can then change the leads on the DMM and check the short circuit current. 

[SparWeb]

Careful not to trip the fuse in your DMM.  When you go to measure AMPs on the meter, do what you can to take a guess first.  If you read the label up close, you might be able to read it more clearly than it is in the advertisement.  Knowing that, test only one panel separately to be sure they aren't putting 2-panels worth through, which could exceed your meter's fuse rating.

[FarmerGreen]

Well, I went to see the panels Saturday. They look just fine, almost new. Checked them with the DMM and they were each putting out 17-19volts. Between 3-3.5 amps. It looks like someone peeled the rating stickers off the backs of all 4 panels, but I could barely make out what was written on one panel. As near as I could tell they are 60watt panels. Does that sound right with the other measurements? Anyway, I bought them and the charge controller and meter for $300. These are going to be used to operate a 15 amp DC water pump motor for a Simple Pump.

[dnix71]

4 x 60 watts for $400 is $1.67/watt. That's a pretty good price is the panels are clean. The rest of the stuff is just a bonus. You'll need the controller to go with the panels. The batteries could be taken to an auto parts store for recycle and new batteries bought.

[FarmerGreen]

It came with a Trace 30Amp charge controller a hinged frame, and a meter. The batteries were toast so he kept them to recycle. Said he could get $10 each for them. But, I talked him down to $300 for everything.

[SparWeb]

He shoots, he scores!