I know this an old and ongoing topic, but let me simplify it! I need 6-8volts, for my 48v, and it only gets minimal use at best. What is the most bang for the buck, pure and simple, no graphs, no comparison charts. I simply want the person who knows batts. to tell me I don't have to replace my T-875 with like, if I don' really need to. I've heard Interstate Blue caps, Deka's, Exides, etc., may be a survey would be better?