SN-3871S-7 (also known as Energy Cell 7) is the seventh of nine Energy Cells in Metroid Prime 3: Corruption. Samus can recover it while searching for NZG41. To start, she must find a Combination Lock and decipher a puzzle on it with the X-Ray Visor. This opens a door to the right of terminal, revealing an elevator, which Samus can use to go under the floor, and reach a fork. The left path takes her to the Cell. Removing it releases the Phazon Metroids.