MacBook Battery Replacement

MacBook batteries are consumables, not faults. Apple rates most of them for around 1,000 full charge cycles, after which the cell is doing well to hold 80% of its original capacity. You can check yours in seconds: hold Option, click the Apple menu, open System Information and look at Power. Cycle count and condition are both there, and they tell you whether you need a battery or something else entirely.

A swollen battery is the one to act on straight away. Because the cells sit directly under the trackpad and the bottom case, swelling shows up as a trackpad that has stopped clicking properly, a case that rocks on the desk, or in bad cases a lid that no longer closes flush. Stop charging it and stop using it — a swollen lithium cell is a fire risk, and left alone it will eventually push hard enough to crack the trackpad or the display.

On Retina MacBooks the battery is glued into the top case rather than screwed in, which is what makes this a job worth paying for rather than attempting. The cells have to be released with the correct solvent and lifted without bending or puncturing them; levering them out with a metal tool is how a routine battery replacement turns into a fire in a kitchen. We do it properly, recalibrate afterwards, and check the charging circuit at the same time — because a battery that has been running hot often sits alongside a charge port that has taken a knock.