 The Volt 's nominal usable battery capacity is 10 @.@ 3 kWh . The Volt 's fuel tank capacity is 9 @.@ 3 US gallons ( 35 L ; 7 @.@ 7 imp gal ) . Aside from charge sustaining modes of operation , the battery capacity is completely used first , and then the fuel is consumed . In the event that the car is operated until it runs out of gasoline , the gasoline @-@ powered generator shuts down , and the Volt continues to operate , tapping into a reserve portion of the battery capacity which is below the regular minimum state @-@ of @-@ charge . The reserve battery capacity provides an extra 3 to 4 mi ( 4 @.@ 8 to 6 @.@ 4 km ) . If this reserve battery capacity is also exhausted , the Volt slows to a stop . 
