Patent attributes
A system incorporating a smartphone and an add-on device coupled to each other via combined data/power interface, the smartphone having a rechargeable battery connected to battery protection circuitry and the add-on device optionally having a rechargeable battery connected to battery protection circuitry as well, the combined data/power interface having one or more data pins for transferring data between the smartphone and the add-on device, one or more regulated power delivery pins, and one or more protected-battery power delivery pins, wherein the regulated power delivery pins are used to charge the battery of the smartphone from an external charger coupled to the add-on device, the batteries are connected to the battery protection circuitries that is configured to protect the battery by cutoff or limit the current or voltage on the battery electrodes, and the protected-battery power delivery pins are connected to the battery protection circuitries of the smartphone or add-on device.
