Infinite Battery Energy
To obtain infinite battery energy, follow these steps:
Navigate to your Outlast settings: C:\Users\[your username]\Documents\my games\Outlast\OLGame\Config
Look for OLgame.ini within that folder and open it with Notepad or a similar text-editing program.
Search for "bat" (without the quotation marks) and that search should lead to a series of lines in the file that appears about as follows:
OLGame.OLCheatManager]
bCheatsEnabled=false
bUnlimitedBatteries=false
Update the setting of the second and third lines so that they read "true" instead of "false" and save the file. When you play next, you'll have infinite battery energy.
Invincibility Hack
Note: Make a back-up first. Navigate to C:\Users\offic_000\Documents\My Games\Outlast\OLGame\Config and you will see a file named OLEnemy. Open it and then make some changes. As you scroll down, you'll find things under titles such as [OLGame.OLEnemyPawn] and [OLGame.OLEnemyGenericPatient_G]. These are enemy titles that contain codes such as NrmAttackNormalDamage=51, NrmAttackThrowDamage=51, HardAttackNormalDamage=101, HardAttackThrowDamage=101, and so forth. You want to change those values from their current numbers to 0. There are quite a few to change, so the process could take quite some time. Make sure that you only change digits that relate to the values specified above. The end result once you change all appropriate entries is that no enemies will be able to inflict any damage.