Fission Battery (Fallout 3)

A fission battery is a miscellaneous item in Fallout 3 and Fallout: New Vegas.

Background
Produced among others by Wattz Electronics, the fission battery has taken on the role of an on-hand generator. Throughout the Mojave Wasteland, fission batteries can be found in New Vegas streets, remote shacks in the wastes and reoccupied suburban homes. They are used for powering a wide range of devices, like street lamps, electronic signs, light-bulbs and other household appliances and are easily scavenged from the common robot or appliance store, making it invaluable to the common wastelander in the absence of a reliable power grid.

Fallout 3

 * Reilly's Rangers: A fission battery is required for fixing an access elevator during the quest, at the top of the Statesman Hotel. One can be found inside the hotel, if needed.
 * A fission battery is used in the construction of the railway rifle.
 * A Spoonful of Whiskey: 6 fission batteries are required for the Point Lookout repeatable quest.

Fallout: New Vegas

 * Cass' moonshine: A fission battery is required to make Cass' moonshine.
 * Not Worth a Hill of Corn and Beans: Four fission batteries, along with many other supplies, are needed to repair a food processor.
 * My Kind of Town: Three fission batteries and 4 conductors can be used to reprogram Primm Slim to be the sheriff of Primm.
 * A fission battery, along with two pieces of scrap metal, are used to make Sierra Madre chips (listed as 'Sierra Madre Slugs' in-game) with the Coin Operator perk in the first add-on for Fallout: New Vegas, Dead Money.
 * Can be converted to energy cells in Honest Hearts.