Tech question solar panels

[quartersplash]

I have 600 watts of solar panels in 2 separate intallations on my cat. One set is 4 90 watt panels hooked to a 30 amp regulator and the other is 2 120 watt panels hooked to another 30 amp solar regulator. Historically the 2 systems together would register 50 or 60 amps charging in full sun and before the regulators they would put out 17+ volts.
I left the boat for 2 months and when I got back, the charging seemed slow, so I checked the panels and only had around 14 volts charging before the regulators. What is strange is the both of the separate systems were exactly the same...Same charging rate. Also in full sun, both systems together were only putting out around 25 amps.
One thing is that there is lots of lightning here right now and many boats have been hit. I am wondering if something could have got blown out, but again, both systems are doing the same thing.....
Please help.
Thanks

[Ex-Calif]

I am not an expert but I would methodically isolate and measure each panel separately and see if you can isolate one or more bad ones. This is also an opportunity to check all connections for security and corrosion.

Also if not done so I would clean them before and after measuring.

[Captain Bill]

Originally Posted by quartersplash

I have 600 watts of solar panels in 2 separate intallations on my cat. One set is 4 90 watt panels hooked to a 30 amp regulator and the other is 2 120 watt panels hooked to another 30 amp solar regulator. Historically the 2 systems together would register 50 or 60 amps charging in full sun and before the regulators they would put out 17+ volts.
I left the boat for 2 months and when I got back, the charging seemed slow, so I checked the panels and only had around 14 volts charging before the regulators. What is strange is the both of the separate systems were exactly the same...Same charging rate. Also in full sun, both systems together were only putting out around 25 amps.
One thing is that there is lots of lightning here right now and many boats have been hit. I am wondering if something could have got blown out, but again, both systems are doing the same thing.....
Please help.
Thanks

Solar panels are semiconductors and they can be directly affected by lightning. I had a lightning hit in June. My panels would put out 16-17 amps in mid-day sun before the hit and I have not seen over 13 since the hit. I suspect they took part of the hit because it knocked out my controller which I replaced.

[belizesailor]

When you test the voltage before the regulators are you disconnecting the regulators so that you get full open voltage?