Our new range of MaXx lights already have impressive burn times which are more than adequate for most people. However, the "Piggyback" battery feature allows the burn times to be extended almost to the point of infinite! Simply by plugging a "Piggyback" battery into the charger port and attaching the extra battery beneath your stem you can add burn times equivalent to the Joystick or Enduro MaXx. Our "Piggyback" batteries use new cell technology manufactured by the World leaders in Lithium Ion battery technology - Sanyo. The idea of the Piggyback battery is to plug the battery into the light at the start of use. This will allow you to use the light on MaXx, Ride and High for a largely extended period of time. If the battery is plugged in with the light half charged, the Ride and Low modes will be avilable.