Abstract: An integrated mobile tool and welder power supply system includes a primary DC power source coupled to a power supply chassis for supplying DC power to DC-operated power equipment such as welders and AC power to AC-powered equipment such as standard AC power tools. The power supply chassis houses a power inverter for transforming DC power from the primary DC power source into AC power and one or more power converters for supplying a recharging current to the primary DC power source from one or both of an external AC power source or an external DC power source. The power supply system can be configured such that if an external AC power source is available, that AC power source is electrically coupled to an AC output terminal for supplying AC-powered tools. In one embodiment, the switching of AC output power from the power inverter to the external AC power source may be overridden by means of an AC output mode selection switch.