Patent ID: 7863856

Claim:
A system for bi-directional battery charging, comprising: a first electronic device, comprising: a first rechargeable battery, for providing power to the first electronic device; and a first battery charger; and a second electronic device, comprising: a second rechargeable battery, for providing power to the second electronic device; a second battery charger; a voltage boost that receives an input voltage from said first rechargeable battery and is selectively enabled to either up-convert the input voltage as input to said second battery charger, or else to pass the input voltage through unchanged to said second battery charger; and a controller for programmatically controlling said first and said second battery chargers and said voltage boost, wherein said second electronic device attaches to said first electronic device to operate in combination therewith, and wherein said controller is programmed to decide, based on the voltages of said first and said second rechargeable batteries: (i) whether to supply power to said second electronic device from said first or second rechargeable battery, (ii) whether to charge said second rechargeable battery from said first rechargeable battery, and (iii) whether to enable or disable said voltage boost.