battery depletion and replacement

[Solar Express]

Greetings - I need some community wisdom and guidance on my batteries.

I have 2 Renogy 200 Ah AGM's. They will be 2 years old in January. They are powered by 3 100 watt panels. Recently I rarely see the power levels from the panels at more than 140 watts (not sure if this is due to fall desert sun. But I recall power was typically 270 watts). The power demand is mostly from a small 4.4 ft3 Magic Chef refrigerator. I shut it down at sunset to save the batteries. I tend to play a radio all night.

Until recently, the battery levels would read 60-70% at sunrise and quickly fill to 100% after a few hours of sunlight. Even with the fridge on, they would remain at 100% and be in float mode all day.

Now, I shut down by 3 pm, the batteries never reach 100%, never go to float mode, and I'm not running radio all night, as levels at sunset are 60% and dropping to 50% quickly. If I run radio, it's 40% at sunrise. Lat night, I got a warning for low battery level of 38% and shut it down.

I'm assuming batteries are dying. Is that right? How much time left before I must replace? Any ideas on how I can prevent furred degradation? Better battery replacement? I spent $800 on these batteries and 2 years lifetime seems bad.

[john61ct]

Yes, Renogy does not make great quality AGM, nor anything else really. And at $800 that's insanely poor value.

Seems to me sooner the better if mission critical. Do you really **need** AGM?

But better to learn more and get proper monitoring gear beforehand, so you can take better care of the new bank.

From what instrumentation are you reading

Panel output in watts?

Charge voltage going into the bank?

SoC% of the bank?

100% Full can never be reached in less than 6-7 hours depleting that low.

What other input sources do you have besides not enough solar?

How many nights are you on average off grid?

Shutting a fridge down at night does not save any power, in fact wastes it, but that's another topic.