Troubleshooting Solar Panel/Generator Combo

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Moebius01

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Advocate I

1,515
TN, USA
First Name
Jason
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Jowers
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28732

Ok, understanding I'll likely need to dig through some solar panel forums (open to suggestions on those btw), figured I'd start here as plenty of folks use solar. Long story short, I'm trying to figure out the best approach to test a solar panel.

As far as solar generators go, the only one I have right now is a Togo Power Advance a350. Got it mostly as we're just starting to go truly off grid, don't have a fridge yet, and just needed something to top of the phones and rechargeable lights and such over a weekend style trip. It'll work for the purposes. Plus, it was pretty cheap, especially since I had some Amazon gift card balance. :)

This week, I picked up a cheap (and that might be the problem) 100w folding panel on Amazon. They're supposedly Sunpower cells. When I first hooked it up to the a350 to test, I was getting 35-40 watts. It was direct sun, so that seemed a little low, but not awful. However, within about 5 minutes, once the panel heats up a bit, it drops to 12 watts in max. Tried it with the panel off of the ground to get a little more airflow and less radiant heat, but same result. Let the panel cool for a while, tried again, same thing. I actually assumed it was a faulty panel, and did an exchange with Amazon. New panel came today, hooked it up, and same thing. So now I'm assuming it's not the panel. I did a quick test with a multimeter, and the panel seems to be putting out 18 volts which I gather is about what it should be. I don't have an easy way to check the amperage unfortunately (or if I do, I don't know how :)). Side note, the a350 has only one input plug (DC, 8mm), and when I hook up the AC adapter with the same input, it pulls between 65-70 watts to charge.

To be clear, I know next to nothing about solar. This is my first time even playing with a panel. That said, I'm trying to figure out how to tell if it's just a crap quality panel, some incompatibility between this particular panel and the a350, or something else. Is there something else I can test to further isolate the issue?
 

dchurch

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Oregon, USA
First Name
David
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Church
A 100W panel should put out at least 70w in full sun, 40w is awful. The solar panel output should not drop that much when the panel gets hot.

From what i see on line the a350 should max out at 80w input (12v-28v), so a 100W panel is a good choice.

If I understand correctly: The wall charger uses the same input as the solar panel. The wall charger input is fine. The solar input is not. Is there an adapter or extension cable that is used during solar that is not being used with the wall charger? If so that could be the problem. If not the solar panel appears to be the problem.

I don't know about the Togopower a350 but I have a Togopower 120w folding panel. It works great!