USB and FireWire Car Charger. Use your car to charge any devices (digital camera, PDAs, mobile phones, USB accessories and many more) that can rely on USB or 1394a FireWire for power. Just plug the USB/1394a car charger in the cigar lighter of your car. Connect your USB/1394a device to the USB car charger. Remove the USB/1394a car charger when it is not in use as some cars may still provide power to the socket even when the ignition is off. Input Voltage: 12V ~ 24V, 2A, 24W ~ 48W. USB Output Voltage: 5V, 500mA, 2.5W. 1394a FireWire Output Voltage: 12V, 500mA, 6W.