Fallout 3 Equipment Database: Item Details
Alien Power Cell  
Category: Miscellaneous
Type: Ammunition
Item ID: 00029364
Weight: 0
Value: 10
• MDPL-13 Power Station - Found on ground next to alien "Recon Craft Theta" ship to the north
• Fort Bannister - Found in crater to the east
• Old Olney (Olney Powerworks) - Found in control room
• Adams Air Force Base (Launch Platform Base) - Found in armory
• The Citadel (Armory) - Found on shelf (if you bomb The Citadel during the Who Dares Wins quest)
• Mothership Zeta (Steamworks) - Found on shelf
• Mothership Zeta (Robot Assembly) - Found on shelf
• Mothership Zeta (Weapons Lab) - Found on shelf
• Mothership Zeta (Biological Research) - Found on shelf