I BOUGHT A USED JAZZY JET 3 ULTRA WITHOUT BATTERIES AND I HAVE BOUGHT 2 NEW BATTERIES BUT AM NOT SURE HOW THE WIRES HOOK TO THEM, IF THE 2 BATTERIES HOOK TOGETHER.

Locate the two wires from the circuit breaker attach one wire (black if marked) to the negative post of the rear battery and attach the other wire (red if marked) to the positive post of the front battery. Locate the two wires coming from the power module plug with a red and black wire. Attach the red wire to the rear battery positive post and the black wire to the front battery negative post. attach the joystick to the nine pin plug at the rear of the chair and turn it on. You should have power at the joystick and the chair should work. Disconnect the joystick put the shroud cover back on grease the seat post and reattach the seat then plug in the joystick and charger plug at the rear of the chair. Charge the batteries before use and charge them overnite for the next 20 days. If you use the chair daily charge your batteries everynite while you sleep unplug in the morning. If you don't use the chair daily charge at least once per week or after you use the chair. Always put the chair up fully charged if you are going to be out of the chair for an extended time the disconnect the batteries at the large plug going to the power module Hope this helps you