macOS · Mac · Everyday fixes

Keep your Mac battery healthy

Lithium batteries age from heat and from sitting at full charge. macOS has one setting that quietly slows both down.

Before you start

Low risk. This change is reversible — you can return to the previous state without professional help or data loss.

System Settings → Battery → make sure Optimised Battery Charging is on — it learns your routine and holds below 100% until you usually unplug
Check health any time: System Settings → Battery → Battery Health — 'Normal' with a good max capacity means you're fine
Avoid sustained heat: no duvets, no direct sun while charging; a hot MacBook is an ageing battery
Apple Silicon Macs handle charge cycles well — if the battery's health drops below ~80%, that's the point to consider service

Optimised Battery Charging is on, and Battery Health shows Normal with a good maximum capacity.

Health drops below about 80% max capacity — consider Apple service; no setting will reverse that ageing.

Next stop: the related fixes below, or start a guided diagnosis.