Is my panel toast?

[pierreyves]

Hi All, first post! I bought a 15 W solar panel kit to experiment with charging a deep cycle battery. The panel (One of these http://www.google.com/products/catal...d=0CIkBEPMCMAA) Lasted through several camping trips and jostling around in the back of my car, where I would use it to charge my cell phone when the car was off.

One day ... The light on my cell phone charger (Plugged into the panel - 12V) turned on but the phone wouldn't charge. I put the big panel next to a tiny panel, and put a load on both, and the tiny panel gave higher current readings. (30 milliamps or so). I emailed the manufacturere who said take a voltmeter in full sunshine and measure voltage as first step. Here's the weird thing: It appears to be reversed (+ to -). I get 20 volts open circuit when measuring black to red and red to black.

There are not obvious cracks or breaks in the panel.

If the answer is "It is toast, get rid of it and buy another, and next time, secure it in the back of your car so it doesn't bounce around so much" Cool But if not, I would love to save/ fix this unit. I've already removed all the plastic and am left with a solid piece of glass and some wires that are epoxied to a hole in glass Can you all recommend a good replacement for my rough-and-tumble lifestyle?

Thanks much in advance,

[Mike90250]

.... Can you all recommend a good replacement for my rough-and-tumble lifestyle?...

Sorry, can't help much diagnosing a couple of wires in a hole.

A rugged panel, is made by Unisolar. It's Thin Film, on a aluminun or stainless substrate. Plastic cover, no glass. A buddy of mine has one, 10 years old, that some vandals shot a couple holes in years ago, it's still working. I use a Unisolar 64, on my monolith.

Mono_2005_CS_056_c.jpgPhoto is of what I call, my Solar Monolith. (How-To) A group of us bought several Unisolar 64 panels back in 2001, as part of the Alternative Energy Zone Village at Burning Man. I wanted to make a self-contained "box" that was portable [ha!] and did not drag a bunch of wires around.

[BooneyLiving]

@Mike90250 - That's really cool! I love it when I see people come up with portable solar power solutions like this.

[pierreyves]

re: Is my panel toast?

Thanks Mike for the response. I will look into your recommendations for a replacement. Yes Burning Man is the inspiration for quite a few interesting projects!

[pierreyves]

re: Is my panel toast? -> Solved

OK - All is good. Having nothing left to lose I pulled the panel completely apart. Saw a loose wire - and epoxy/soldered it back to place. Thought I was golden, but no love. (Turns out i probably pulled the wire off myself) However, there is a blocking diode inside the case that wasn't conducting current in either direction. Bingo. For similar people having the same problem. Symptoms:

1. Very little current out of your panel
2. + and - reversed, MY OCV was supposed to be 20V in full sunlight, was about -14V

On the Sunforce panel, the blocking diode is near where the wire exits panel in the middle of the top of the casing. You could probably access it by carefully melting a 1 sq " hole in the plastic on the face to avoid having to unscrew the handful of tiny screws, then filling the hole with silicon caulk when done.

I just took the blocking diode out and connected the wires - knowing i will need one inline or a charge controller.

Yeay - hope this helps someone.

[Mike90250]

I'd venture to guess that the blocking diode fried when the PV was hooked up wrong, and it saved your panel from damage. A small diode is cheap insurance, get a new on installed.

[pierreyves]

Aha - yes - that is very good advice. Thx