BMU Battery (Daughter Board) Mylar Cover

About this part

The BMU Battery (Daughter Board) Mylar Cover (Apple part number 923-01451) is a genuine Apple part that fits the MacBook Pro (13-inch, 2019, 4 TBT3), MacBook Pro (13-inch, 2018, 4 TBT3), MacBook Pro (13-inch, 2017, 4 TBT3) and 1 other model. The battery powers the Mac away from the wall and also steadies power delivery under heavy load, so a worn cell affects performance too.

Before you order, match the model identifier on your Mac (Apple menu, About This Mac, System Report) to one of the identifiers listed for this part: MacBookPro15,2, MacBookPro14,2 and MacBookPro13,2.

Signs the battery needs replacing

• "Service Recommended" in the battery status menu
• Short runtime, or the Mac shuts off at 20 to 40 percent
• A swollen battery lifting the trackpad or bottom case
• Slowdowns that disappear when the charger is plugged in

Not sure the battery is the real cause? Our battery repair service starts with a full diagnosis, and we can install this genuine Apple part for you through our MacBook Pro repair service, in our Tampa shop or by mail-in repair from anywhere in the US.