Solar panel short circuit current ...is my panel faulty?

[FairweatherDave]

It was suggested I should measure my solar panel output before the charge controller - short circuit current and open circuit voltage. So I duly disconnected the panel from the controller. I measured in bright mid day sunshine and was happy to see 20 volts. But I expected to see a higher short circuit current. I could only get 0.65 amps when the spec sheet suggests 2 amps at least. It is a 50 watt panel bought in 2018. The panel is mounted flat on the coach roof and as I say had full midday sun, no obstructions. Is 0.65 amps acceptable? (In my previous thread I have said I don't think my solar is doing a decent job of charging). Advice much appreciated.

 

[William_H]

It certainly looks like your solar panel is bad. You might try lifting the panel to get it square on to the sun which may make some difference but you should be getting 2 amps hopefully 2.5 amps. Look for signs of corrosion in the panel like under the glass. ol'will

 

[FairweatherDave]

Thanks ol'will. Unfortunately the panel is glued down with sikaflex. However to my untrained eye I can't see anything wrong with it. It is a Photonic Universe semi flexible panel that is supposedly a robust product. Yes it could get damaged but I'm pretty careful to avoid stepping on it etc. But over 4 years the odd accident maybe has damaged it. Can't see anything wrong though.

 

[AngusMcDoon]

Thanks ol'will. Unfortunately the panel is glued down with sikaflex. However to my untrained eye I can't see anything wrong with it. It is a Photonic Universe semi flexible panel that is supposedly a robust product. Yes it could get damaged but I'm pretty careful to avoid stepping on it etc. But over 4 years the odd accident maybe has damaged it. Can't see anything wrong though.

The semis don't last long, which is one of their downsides. Failure after 4 years is not completely unexpected.

 

[jac]

The only thing you could try would be to carefully wash it with fresh water. doesn't take that much dried salt, general dust and crud to affect them quite badly and if getting old as well, not quite aligned , minor obstruction etc...