We’re happy to help you find your 2018 Jeep Compass’ start/stop battery location!
Your Compass has two batteries: the primary 12V battery like you’d find in any other car, and then a smaller secondary battery used by the electronic start/ stop feature. Both batteries are found together on the driver’s side of the engine, a bit deeper than the coolant reservoir.
There’s a battery relay module located on top of the start/ stop battery. This has two 10mm bolts holding it in place, which you’ll need to remove. The module should then slide up and off of the battery. You’ll need to remove the plate beneath that, as well as the battery warmer, and then the battery itself should come out.