I've had them for almost two years. They are generic alibaba type SLAs. It seems like the capacity is getting really bad, such than the SOC is more than 25% off compared to the rated capacity. I never let them go lower than 60% according to the original SOC calculation. I'm not in an area with a lot of daylight hours currently. They're supposed to be 12v 250AH SLAs, and I have 4 of them in a 24v configuration to be 24v at 500AH. Here are my graphs and charge/BMV settings, as you can see it goes to 24v at like 80% SOC. 100% SOC sync happens when the batteries are getting like 300watts. Midpoint looks okay so shouldn't be a bad cell. Is there anything I can do aside from halving the BMV amp hours?