It's called UPS (Uninterruptible Power Supply). It saves power so the computer can keep running after the power goes off. The time it keeps running depends on the type of the UPS Actually, you have several options. The most obvious is to purchase a power back up unit for computers. Wal Mart, Sam's Club, eBay. Buy a auto jump starter. These are made with built in flash lights, radios, lighter sockets, 120Vac outlets, and jumper cables. If you really want to go out on a limb, get a power inverter (300kw-750kw should be enough) that can be plugged onto the lighter socket in your car. Start the car, increase the idle, plug in computer.