A jump starter unit for starting large vehicles and other equipment using jumper cable at lengths up to fifty (50) feet. The jump starter includes a high output (200-300 amp) alternator and a large (2000 Farad) capacitor. The alternator is also used to maintain the capacitor's charge when the boost charge is not needed. The alternator and capacitor are integrated into an electrical system that includes an electronic control and a plurality of relays that provide the various charging and boost functions of the unit. In certain embodiments, the jump starter unit may take the form of a portable or mobile self contained apparatus having its own combustion to drive the high output alternator. In other embodiments, the jump starter unit may be integrated into a service vehicle, such as a tow truck or utility vehicle, and utilize the vehicle's engine to drive the jump starter's high output alternator.