... , computer USB port and 9-volt battery. A must for any traveling family, Brookstone's 4-in-1 Power Charger will keep your smartphone, digital ... of power: your vehicle's power socket, a computer USB port, a 9-volt battery or a standard wall plug. When you're back ... town. The Power Charger is compact, simple to use, has a retractable cord and comes with a charger case. 4 in 1 power charge