The battery in a Volvo XC90 is located behind the left rear quarter panel in the trunk. It’s pretty difficult to get to, though, and you’ll need an 8-millimeter wrench. Fortunately, if you’re just trying to jump-start your Volvo, you can use the jump posts located under the hood.
If you need to replace the battery, on the other hand, you’ll need to get to the actual battery in the back. Start by removing the floor panel and the spare tire cover in the trunk. Underneath, you’ll see a quarter panel secured by a twist lock.
Turn the lock and remove the panel. Covering the battery, there’s another plastic panel that you’ll need to use an 8-millimeter wrench to remove. Once the plastic panel is removed, the battery will be accessible.