One of the most frustrating things about laptop computers is changing their batteries. Now, a London-based company, Radix Techno-logies, has developed a gizino that can circumvent the exorbitant new bat- teries by recharging those stone dead from a car engine.

The device, which plugs into the car's cigarette lighter, converts direct current power from the engine into mains-type power. This pocket doodad, which is about the size of a 35 mm camera, has an output of 150 watts.