A charging device is provided. The charging device includes an input interface configured to receive electrical power from a power source and charge a removable energy storage device using the electrical power from the power source. The power source may be a solar panel. The charging device may include multiple input interfaces configured to receive electrical power at different voltages. The charging device may include an output interface configured to provide electrical power to an electrical device connected to the output interface, and the circuit may be configured to provide electrical power to the output interface from at least one of the removable energy storage device and the input interface.