Hey guys, I have replaced my sons faulty tx after Xmas, anyway after that, I've noticed the car isn't quick off the mark now nor top end either, I'm new and had charged the to nimh packs at the wrong ampage, the batteries are 2000 and 2200, I had charged them at 5 amps, could I have ruined them by doin this or could it be something else, they only got charged 2-3 times each like this