Batteries (sing. Battery) is a piece of equipment used by the protagonists of Outlast to power their camcorders and use its Night Vision Function (NVF). They appear throughout the game in various locations, usually nearby electronic devices, such as radios, Walkie-talkies, etc. They're mostly found one at a time, but, rarely, some areas contain two batteries in the exact same spot. Depending on the difficulty the player chooses, the amount of batteries that can be carried changes, as well as the amount that can be found throughout the game. On normal difficulty a maximum of ten batteries can be held, five on Hard and two on Nightmare and Insane difficulty.
In all difficulties, the player starts off with two batteries in Outlast, while in Whistleblower the player starts off without a single battery. When retrieving the camcorder after escaping Eddie Gluskin's torture, the player loses all of their batteries and the camcorder's power is depleted.
In Outlast 2, when Blake gets captured by Nick and Laird, he will lose his camcorder, all batteries and bandages. In addition, if the camcorder has full battery power, a quarter of it will be automatically drained after it is stolen by Laird.
- The game files for Outlast contain models for a pack of three to four batteries at the same spot that were not included in the final version of the game.
- In the first demo version of Outlast, the player starts off with four batteries instead of two, and can carry up to twenty batteries, four of which are reloaded at once.
- The batteries closely resemble +AA batteries of Duracell brand, but with reversed colors.