Patent ID: 8368346

Claim:
A portable charger device to charge one or more external rechargeable batteries, the device comprising: a chamber configured to hold at least one rechargeable charging battery; and at least one controller configured to: determine a first charging current level to apply to the at least one rechargeable charging battery such that the at least one rechargeable charging battery achieves a first pre-determined charge that is reached within a first period of time of 15 minutes or less; cause a first charging current substantially equal to the determined first charging current level to be applied to the at least one rechargeable charging battery; determine a second charging current to apply to the one or more external rechargeable batteries; and cause a second charging current substantially equal to the determined second charging current level to be applied to the one or more external rechargeable batteries, the second charging current being drawn from the at least one rechargeable charging battery.