Disclosed are systems and methods to provide continuous power to electrical devices using a portable power supply unit and a portable power charging unit. The portable power supply unit may include a first battery providing a first DC output, at least one first inverter for converting said first DC output to a first AC output for powering the electrical devices and for converting a first AC input to a first DC input for charging said first battery The portable power charging unit may include a second battery for providing a second DC output, a second inverter for converting said second DC output to a second AC output; and transmitting the second AC output to the first battery using charging ports on respective units such that said second AC output replaces said first AC output for powering said electrical devices, and replaces said first AC input for charging said first battery.