Does the MiniSting™ have boost mode?

Short Answer: Yes.

Long Answer: Yes, the MiniSting™ can output up to 50 watts when powered by an external 12V deep cycle battery.

Note that using a 12 V automobile battery installed in a vehicle as an instrument power source will void the warranty. Using an automobile battery installed in a vehicle may damage the instrument due to spikes in voltage from the alternator and other systems.  If this is the only 12 V battery available, it has to be disconnected from the vehicle and placed the ground on some insulating material like dry wood or plastic.