At first, this can be a bit finicky and unintuitive, however, using build mode at any settlement will let you set up your Power Armor Station to heal your favorite exosuit of its metallic wounds. Repairing power armor in Fallout 4 will require you to place a suit of power armor within a Power Armor Station and then interact with the station. To get the durability back up, you’ll need to repair it. Whether by a haywire robot’s laser beam or the ravenous bite of a Deathclaw, durability will be lost on your power armor.
Through engaging in battles across the map, your power armor will inevitably get damaged due to incoming attacks.
How to Repair Power Armor (And Why You Need To)