battery depletion and replacement
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.