2001 gem 825e error 51 help

Just got the gem and live out in the country and went around the block and coming up a hill the motor started to smell hot so I stopped and let it cool down. But it never started back up. Someone sent me the troubleshooting guide and get to step 6 and the controller has 72v going across it. Is there anything else that can contribute to the code to check? I did check the batteries and they have little over 12v each but they have the indicator light on them and says it’s not charge just wondered if that would give it a false reading ?