A method is provided comprising: detecting an electrical connection between a first device having a first battery and a second device having a second battery; receiving an indication of a residual power of the second battery; displaying, by the first device, a power sharing interface based on the indication of the residual power of the second battery; detecting an input to the interface specifying a threshold amount of power; transmitting power from the first battery to the second device until the threshold amount of power is transmitted.