I have a 1/6 Nylint Rock Crawler that I recently started messing around with again. So it was just lurching forward, then stopping, then lurching forward, etc., then it stopped really doing anything, just a slight whine from the electronics. I've always read that this means the battery is dead, so I reconditioned it with water and Epsom salts, then charged it for 24 hours or so. Now it's back to weakly lurching forwards, stopping, lurching, stopping, etc. I put the battery on the volt meter and it read about 13.5-13.7 volts. That seems like it should be enough voltage, right? So does does anybody have any idea what's wrong here?