Abstract: A protective case for an electronic device is provided. The protective case includes an interface for connecting to a rechargeable battery, a group of display elements, a device interface for electrically interfacing with the electronic device, and an external interface. The protective case also includes electrical circuitry configured to receive electrical power from an external power source through the external interface, exchange communications with the electronic device through the device interface, determine a charge rate for the rechargeable battery of the electronic device based on information received in the communications, and supply a portion of the received electrical power to the electronic device through the device interface if a condition is satisfied.