Abstract: An all-electric, battery powered industrial or commercial mobile power unit is provided that can include a number of features. The mobile power unit can include a DC electrical energy source configured to produce a voltage of approximately 300-450 VDC. The mobile power unit can be configured so as to produce a user programmable voltage output and/or a user selected voltage output of either 480 VAC 3-phase, 208 VAC 3-phase, or 240 VAC single-phase. The various output configurations are controlled by software with a system controller of the mobile power unit. Methods of use are also provided.