Buying Used Panels

[bajajoaquin]

I took my camper with my new 400 watt solar system on the road for the last week. It worked great and I’m mostly pleased (an issue for another day).

However, I found out that the guy who owns the property where I surf in very rural Mexico was robbed of his solar panels and other things. He says he had 8 panels but not a lot of other info. He didn’t know the voltage. I want to get together some inexpensive used panels but don’t know what to look for. Any advice?

I’ve found these ads on my local Craigslist:
Kyocera Panels
Uni-solar panels

What should I be looking for in buying used panels?

 

[fratermus]

If they are for him it would be useful to know about his controller and battery bank voltage before buying anything.

 

[bajajoaquin]

Yeah that would be nice, but he doesn’t have that info. I asked him what voltage he had and he didn’t know. I asked if he had a controller and his reply was “the little box? Yes.”

He inherited the place from his grandfather who pieced it together over years, I’m guessing. It probably looked a lot like the apocalyptic blueprint in the mobile solar book. Pieced together over years with whatever could be found.

But what do I look for in used panels?

 

[schmism]

But what do I look for in used panels?

lowest cost per watt. IMHO the largest panels you can get ahold of the better. Id much rather deal with mounting 1 400w pannel than 4 100w ones.

your looking at rebuilding the system from scratch with modern tech. start with what pannels you can get and what the budget is and go from there.

 

[bajajoaquin]

Ok, but how do I check for function? I bought myself new panels because I was in a time crunch and couldn’t spend the time learning. But here I’m looking at minimum spend. Is it just lay it in the sun and look for volts and amps at some percentage of rated? Is there a ratio of each? How do I tell if I’m getting a good value or a scam?

 

[schmism]

I dont know of many if any stories of panels that have refused to work without visible damage to them. said another way, with no visible damage you can assume they are going to work at 80% of more of the rated sticker output. I will caveat that in terms of large glass panels. Buying used flexible panels is a no go for me based on quality of manufacture and the propensity for fatigue damage to them.

 

[Brassburnz]

I picked up some used panels in January. Tested the leads with a meter. VOC is 37.8v and that's what the meter showed. Panels were dirty but otherwise in good shape. No dents on the frame. No cracked glass. Where are you located? SanTan solar in Phoenix has used panels.

 

[AE4KR]

If you're careful, and your multimeter has a 10-amp current provision, you can also test for Isc. (That's current under a short-circuit.) A 250-watt panel will push just under 9 amps when shorted. If you don't want to risk your multimeter, just short the panel through a cheap 30-0-30 automotive ammeter. Not as precise, also not as risky.

I wouldn't try measuring 10 amps current through a Harbor Freight or other cheapo multimeter. Neither the leads nor the internal shunts are robust.

 

[Eber]

I picked up some used panels in January. Tested the leads with a meter. VOC is 37.8v and that's what the meter showed. Panels were dirty but otherwise in good shape. No dents on the frame. No cracked glass. Where are you located? SanTan solar in Phoenix has used panels.

I bought used 250 watt panels from SanTan Solar, I have 44 of them up and running and I have no complaints yet....