Hi I have a charging problem. I installed 6 new 8v interstate batteries and 4 gauge cables. My battery charger will charge the batteries for about 5 minutes and then cut off. Batteries charge to around 52 volts before it shuts off. I think it should charge them to at least 58 or 59 volts before turning off. I see posts about the OBC and was wondering if this could be my problem. Any way to test it? Any advice would be appreciated.