Multimode charging device and method

A charging device comprising:

• a housing comprising an output end comprising an output port, a fuel supply end comprising a fuel inlet port and an external power input, and a housing body having cooling vents;
• a fuel cell system comprising an inlet valve actuated by a latching solenoid, a fuel cell stack, a purge valve actuated by a normally-closed non-latching solenoid, a hydrogen pressure transducer, a stack temperature sensor, and a cooling system;
• wherein the inlet valve is fluidly connected to the fuel inlet port to provide a pathway for fluid flow between the inlet valve and the fuel inlet port;
• wherein the purge valve is fluidly connected to the fuel cell stack to provide a pathway for fluid flow between the fuel cell stack and the purge valve;
• a balance of plant comprising a printed circuit board assembly and a battery;
• and,
• wherein the charging device is configured to provide power to the output port via one of the battery, the fuel cell stack, and an external power source electrically connected to the external power input;
• wherein the purge valve is configured to clear excess water vapor from an anode in the fuel cell stack when opened;
• and,
• wherein the charging device is configured to periodically open the purge valve for a total of no more than about 400 milliseconds of cumulative durations of purge valve opening time every 300 seconds and with a hold-up period of about 72 seconds for every 100 milliseconds of duration of purge valve opening time.