I bought a 1997 Club Car for my kids for Christmas and they haven't got to use it yet, need help. The golf cart slows after 5 minutes and shutters and dies. Had new batteries put in (Interstate Deep cycle) 48 volts. Bought new charger, didn't help, replace plug receptacle, didn't fix it, replaced solenoid, still at ground zero. Any suggestions of other things to check, wires look good also. Put tester on batteries all say 7.9 v to 8.3 sitting. Starts off fine, fast then start to low after 5 min, lights start get dim, then off, the carts shutters (Shakes) have to release pedal and lightly press and limp back TO YARD.