I have a Blue Razor Pocket Rocket, and it won't go full speed. first I thought it wasn't charging, so I charged the batteries with a car charger only to find out that they were fully charged. I did a voltage check, and each battery tests to have 13 volts. So I changed the controller and that didn't fix anything. Still, the bike won't go full speed, in fact, it barely moves at all. Is it possible to get 13 volts out of bad batteries? Or is it the electric motor? How can I test these parts?

Toys - Electric - Razor Pocket Rocket Ride-on Motorcycle