Solar panel trouble

Do any solar knowledgeable people want to help me out with a problem I’m having trouble solving?

Background:

I am running 2 100w renogy panels that are about 3 years old on the roof of my GFC for the past three years. I have it all connected to a aux battery system with an ignition controlled isolator. When ignition is on, starter and aux battery are connected. When ignition is off, they are separated.

I have the solar panels connected through a renogy wanderer 30a controller and connected to the six battery. Everything is fused.

Problem:

Over the last two weeks I’ve noticed my panels have dramatically decreased their efficiency and struggle to charge the battery in anything but direct sun. Even with direct sun, it doesn’t boost or flux the voltage between 13.8-15v like it has over the past three years. Cloudy days I would normally be able to run 13.6v and now it struggles to go above 12.8v

I’ve tested the set of panels and they are producing 19.6v direct off the panel. I’ve replaced the charge controller to a ridge Solar mppt with no change.

Connections are solid

Any ideas? Could my panels have failed and still produce the voltage but. It the amperage?

Any ideas ?

Is there someone that has a portable solar panel that you could try plugging in and seeing if you get the boost charge like before? I have heard some folks having issue with the renogy panels after awhile. Knock on wood, my 175w is still good.

That’s a good idea! I have a friend with one panel, I’ll have to give it a try and see if it boost charges.

Is there another brand that is more reliable/stable?

I feel like 3 years is a short time for a panel that advertises the 25 year durability I saw on Amazon

Just seems like the easiest fix/first part to troubleshoot! you could also isolate one panel and if you have a jackery or he does, plug it and see how many watts you’re getting.

Lots of people use Sunflare also but the cost is astronomical compared to the renogy stuff.