[Richard and Rhonda]

I had bad cells in two of my six batteries. The bank behaved exactly as you described, it would not charge fully and would not hold a charge. I charged the bank as best I could and then removed the interlinking cables. After a couple of hours it was evident using a volt meter which batteries didnt hold the charge. The hydometer confirmed both of the bad batteries had a bad cell. You really should let them sit overnight after charging before measuring. But it is critical to disconnect all the cables immediately after charging otherwise the bad batteries will drain the good ones and they will all be at the same voltage. Load testing is more accurate but this simple test may point in the right direction