Upgrade your current twist knob style on - off switch to the new push button Lithium Ion Battery motorbox. You can purchase the complete Battery/Motor Box assembly and install it yourself.
The motor box assembly includes the following:
Motor
Battery
Cap
4 hour charger and adapter
Installation instructions
Used on: Max Li, Max Li CG, Max Li HD, iVac 350 Li, Volt FX-8Li, Millennium Li.