02 Gem E825 2 Slow and Erratic acceleration

Hey guys. I need some help with where to go with a trouble shooting issue. My Gem was running fine the other day. I parked it for a couple of hours and went for another drive just to find it accelerated slowly, only would get half the normal speed and would lurch slightly. The batteries are only a couple of months old and I am extremely careful to maintain the water level and keep them charged.
I checked the voltage and 7 were showing 8.6 v and 2 were at 8.7 v. Tomorrow I’m going to perform a load test to rule out the batteries. My question is, where do I go from there? The controller followed by the motor? By the way, the motor is nearly new as well. I purchased it from Ridr4 Fun. It’s the high performance motor. I want to learn to work on and fix everything myself. I enjoy this car. The problem is I don’t have a maintenance background so I’m really green here. Any suggestions would be greatly appreciated.

Did you find the issue?