Giantz Battery Box 500W Inverter Deep Cycle Battery Portable Caravan Camping USBGiantz Battery Box 500W Inverter Deep Cycle Battery Portable Caravan Camping USB There is nothing worse than needing to be somewhere but your car battery is dead. Or, you need to make a phone call, and your phone isnt charged. What a nightmare! When you need some emergency power, nothing beats the power of a Giantz Battery Box. With 2 12V power sockets, a dual USB socket and two terminal posts, youre covered for a range of charging modes and purposes.