Where can I find the replacement for the charger to plug into the motorcycle? How much for that part?
It sounds like you are looking for the charging port. We carry the charging port with and without wires for your convenience. Please note, there are 2- & 3-wire options available for the Pocket Rocket model so please take a look at the number of wires in your unit to ensure compatibility.
Charging port without wires: https://www.monsterscooterparts.com/brands/razor/models/pocket-rocket/3-prong-charging-socket-without-wires.html
Charging port with 2 wires: https://www.monsterscooterparts.com/brands/razor/models/pocket-rocket/3-prong-charger-port-2-wires-razor-ground-force-go-kart-dune-buggy.html
Charging port with 3 wires: https://www.monsterscooterparts.com/brands/razor/models/pocket-rocket/razor-charger-port-2-wires.html