Passport sound systems are capable of running off a DC power source (battery) using the DC-DC converter. The converter connects between any 12-volt automotive or marine battery and the Passport system. The Fender Passport Battery Pack is a 12-volt, deep-cycle 17 amp battery intended for use with the DC-DC converter. This combination of converter and Passport Battery Pack is capable of powering a Passport system for 6 to 8 hours. An AC adapter is included to recharge the battery.