130w Eco Worthy Flexible panels. Are they my problem or is it me?

[Chetwode Ram]

I'm a complete novice trying to troubleshoot my rudimentary syatem. I have 3 x 130w flexible panels (eco worthy) on my hut, mounted on a slight convex curve. Yesterday they were pointed straight at the sun producing 75 volts but only 0.5 amps? The charger was putting 4 amps in the batteries. I reconfigured them and tried a couple of different tests (running them on their own) but is seems they are all the same. Normal voltage but tiny current. They are a year old. Can they be that rubbish after only a year, is the slight convex curve messing them up or am i doing something wrong? Any help greatly appreciated.

 

[Jordi]

I bought 2 flexible solar panels from Aliexpress a year ago and they are underperforming but not like yours; when new they did max 70% of stated power and nowadays at least 60%. Have your panels always been that bad or is it the first time you use them?

The starting point would be having a load that can take the whole PV array capacity, 390W, such as a battery. For that you'll need to make sure your charge controller is well programmed to the charging voltages of your battery and that your battery is at capacity 50% or lower to make sure you trigger bulk charging; phase in which the 390W are taken.

Then I would test the three panels individually. Connect one to the MPPT and see If you reach at least 90-100W on sunny conditions. Do that one by one and report the results in this post.

If one panel is malfunctioning, it can dramatically bring down the yield of the whole array either in series or in parallel.

 

[Chetwode Ram]

Thank you Jordi, I think i've misunderstood a key element which you've pointed out.. I've just tested the battery and it is at 14.4v, having been charged with a mains charger the other day so perhaps it has triggered the charger into float/maintain mode and I don't have a problem after all! I'll deplete it 50% and check again. Apologies, I'm such a solar novice. Thanks for your help.