The batteries are 8 years old. I have 6 of them.
One saving grace is that they been connected to 350 watts of solar panels for most of their life. My solar charge controller does "float" charging, which I think helps ward off sulfate development somewhat.
The batteries are connected to a Xantrex Prosine 1800, which has an equalization program that can be run. I have never done it. I'd have to implement a battery disconnect switch for the 12V trailer loads in order to use it, so as to not over voltage the trailer loads.
These batteries were in rough shape when I took them out of the trailer. They barely held charge themselves and wouldnt carry a load at all.
I'm amazed at how well my betteries are responding to the desulfate process. I ran a slight over change on 2 sets of 2 batteries all last night. They were bubbling about once per second at the end of the charge.
Yesterday these batteries failed on the 100A CCA test with a battery tester. Today they came up as only "weak". I take this as a good thing given that GCBs aren't designed for cranking an engine. I'm also load testing one set at 20A. It looks like I'll get at least 50AH from them, which is a huge improvement. Still poor compared to new (220AH), but I'll take what I can get at this point. The hydrometer readings have come up as well and are now just low. Prior to this some cells wouldn't even float the hydrometer !
I'll cycle them several times and report back what I achieve.
