An Energy Cell is a small, portable power source used by the Galactic Federation. These Energy Cells serve as batteries to power many of the Federation's technology. Some Energy Cells are stolen and adapted by Space Pirates. Energy Cells have only appeared in Metroid Prime 3: Corruption thus far. In Corruption, Samus uses all but one of them to power the demolished G.F.S. Valhalla.
Throughout the Kalandor Region and the Pirate Homeworld, there are ten obtainable Energy Cells, which are to be used on the G.F.S. Valhalla. One, however, must be used in the G.F.S. Olympus. Six Energy Cells are necessary on Valhalla, leaving the remaining three optional. These optional Energy Cells can be used to obtain a Ship Missile Expansion and a Missile Expansion. Samus can learn the locations of any unobtained Energy Cells by scanning blue terminals found on the Valhalla, which will add the location of a to her inventory.
- "Energy Cells were designed as a portable power source for the Federation. Their high power-to-weight ratio makes them ideal for powering a wide variety of equipment. Throughout the environment you may encounter stations that contain an Energy Cell. Removing the cell will leave these stations permanently offline. You will then be able to place the collected Energy Cell into a new station that is empty. Your collected and used Energy Cells are recorded in your Inventory." — Logbook "Energy Cell" (Metroid Prime 3: Corruption)