Mr. Heater’s HERO features a built in battery and charging system that provides the ultimate in portability by delivering 35,000 BTUs of heat for a full day of work on a single charge. Producing 35,000 BTUs, the HERO’s unique cone-shaped design and custom engineered fan reduces turbulence and produces more efficient heat while keeping the unit cool to the touch. And while traditional propane heaters are loud and irritating, HERO’s output noise is cut in half with patent-pending Quiet Burner Technology.