Fission Battery (Fallout 3)

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

Nature
While the exact makeup of the fission battery is not canonically known, it can be inferred from the name that it is a portable power source that derives its energy from nuclear fission. While it may be tempting to assume that it is a tiny nuclear reactor derived from some miraculous, futuristic pre-war technology, the sheer technological difficulty of miniaturizing a fission reactor to such an extent is so tremendous that it renders this theory implausible. It is more likely that fission batteries are a form of RTG, although if this is true they must employ a material with an extremely long half-life as they continue to function more than 200 years after being manufactured. It may be that fission batteries are stocked with a stable isotope that is only incited to decay when it is required to generate power, perhaps by controlled neutron emission – not a true nuclear reactor, but still more sophisticated than a simple RTG. Fission batteries probably also contain some sort of acid, as they are an ingredient in moonshine.

Use
In post-war society, 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
Fission batteries are located throughout the Capital Wasteland, The Pitt, Point Lookout and Adams Air Force Base, usually in toolboxes or destroyed robots.
 * 19 on shelves and counters in the Franklin Metro utility west rooms.
 * 9 are located in Pinkerton's lab in the broken bow of Rivet City (counts as stealing).
 * 2 are located next to a first aid box on a table, directly to the right of Vault 92's vault door.
 * 3 can usually be found in the Mechanist's Forge in the robot repair center.
 * 5 are located in Hubris Comics Printing on the lower level, 1st room on your right at the bottom of the southeast corner stairs.
 * 5 are located on a shelf facing the eastern wall in the lowest level of the National Guard Depot, next to some generators.
 * 2 can be found in a crate by Dr. Lesko's desk in the Marigold ant queen's chamber.
 * 2 can be found Next to the VAPL-84 power station in the truck guarded by 1 or 2 yao guai.
 * 1 can be found in the kitchen in Zane house in the Minefield.
 * 1 can be found in the yao guai tunnels, behind you on a shelf near where the scripted yao guai runs past.
 * 3 can be found on a table in Smith Casey's garage.
 * 3 can be found in Gallo's storage closet in the County sewer mainline after killing him and taking the key.
 * 3 at the store on Scavenger's bridge
 * A great number of fission batteries can be found in the Point Lookout expansion. They will often be found in places you might not expect, such as in suitcases or wardrobes.
 * Sold by merchants as a miscellaneous item.

Fallout: New Vegas

 * 31 In the basement of the REPCONN test site.
 * 9 spread over 3 floors in REPCONN headquarters.
 * 9 in Vault 11's living quarters and 2 in the lower level.
 * 9 in Vault 3's recreation area.
 * 2 in Zapp's Neon Signs.
 * 2 in Victor's shack.
 * 8 are for sale in Miguel's Pawn Shop.
 * 2 can be found in the The Gourmand kitchen where the bathrooms are; just past the bathrooms, there is a small supply cabinet. They are on the third shelf down, underneath a toolbox.
 * 1 can be found in Michael Angelo's workshop in the machinery shop where the lathe is, across from the fire hose box, on a metal shelf next to the toolbox.
 * Can be bought from Old Lady Gibson at the Gibson scrap yard.
 * A good amount (around 13) can be found in the Securitron de-construction plant in the Big MT in Old World Blues.
 * Inside Vault 22 in a storage room, along with various other items, such as scrap metal and wonderglue.
 * A few can be found at Cerulean Robotics in Freeside.
 * 1 can be found in the shack at Southern Nevada Wind Farm
 * 2 inside Harper's shack
 * 1 inside Lone Wolf Radio.

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, but it is much easier to keep one extra in your inventory and bring it along for the quest.
 * 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, which can be in turn converted to other energy ammunition types.