I am trying to repair my son's electric quad. I thought it might be the batteries but the batteries are both reading 12v. I had to cut wire leads that were soldered to the battery so that I can test the batteries. Now, that I know it is not the batteries, I have to solder back the wire leads to the batteries. I was soldering the wire to the negative post and I was doing fine, however, I must have touched the positive post and I got a small explosion. It scared me so I stopped.
The quad uses two 12v 2amp batteries that are wired together. The wires then have a lead that plugs into the quad.