I had dropped my Mac Air on a tile floor and it would only boot up when plugged in. If the magnetic connector was jiggled the computer would shut down. Not fun! I taped the connector to the computer but even so, it would easily shut down unless handled like a case of eggs. Bought the pentalobe screwdriver from Ifixit. Had the back off in a flash. Gave the plastic tab on the battery connector a little push. Felt it click back into place. Replaced the back. Battery now working again. Thanks! Saved a trip to the Apple Store and probably a lot of cash.