Calibrating Your MacBook, Air, or Pro Battery

All MacBook, MacBook Pro, and MacBook Air portables use a battery with an internal processor designed to maximize battery performance. To make accurate predictions about the remaining battery charge, the battery and its processor must undergo a calibration routine. In this guide, we show you how that process works.

How to Calibrate Your Newer MacBook, MacBook Pro, or MacBook Air Battery

Apple's newer MacBooks and MacBook Pros don't have to go through the same calibration process as older iterations. Allow the MacBook to discharge completely and power off. Then, plug in the power cable and charge the battery to 100 percent. During this time, macOS automatically calibrates the battery.

How to Calibrate Your Older MacBook, MacBook Pro, or MacBook Air Battery

To calibrate an older MacBook:

1. Fully charge the Mac. Don't go by the battery menu. Instead, plug in the power adapter and charge the Mac until the light ring at the charging jack or the power adapter light turns green, and the on-screen battery menu indicates a full charge.

2. Once the battery is fully charged, continue to run your Mac from the AC adapter for two hours. You can use your Mac during this time as long as the power adapter is plugged in and the Mac runs on AC power and not the Mac's battery.

3. After two hours, unplug the AC power adapter from your Mac. Don't turn your Mac off. The device transitions to battery power without any trouble. Continue to run the Mac from the battery until the on-screen low-battery warning dialog appears. While you wait for the low battery warning, continue to use your Mac.

4. When you see the on-screen low-battery warning, save any work in progress and continue to use your Mac until it automatically goes to sleep because of extremely low battery power. Don't perform any critical work after you see the low-battery warning. The Mac will go to sleep before long and with no other warning. Once your Mac goes to sleep, turn it off.

5. After waiting a minimum of five hours (longer is fine), connect the power adapter and fully charge your Mac. The battery is now fully calibrated, and the internal battery processor will deliver accurate battery-time-remaining estimates.

When to Calibrate the Battery

When you have an older MacBook or MacBook Pro, you may forget about the calibration process. It doesn't hurt the battery if you forget to perform the calibration routine; it just means you're not getting the best possible performance from the battery.

However, after the battery is calibrated, its remaining time indicator is more accurate. Over time, as the battery accumulates charges and discharges, its performance changes. The appropriate time between calibrations depends on how often you use your Mac. The process doesn't hurt anything, so it's safe to calibrate the battery a few times a year.

Tips for Optimizing Battery Usage

There are plenty of ways to reduce battery usage on your Mac. Some are obvious, such as dimming the brightness of the display. The brighter the display, the more energy it uses. You can use the display preference pane to adjust display brightness.

Other ways aren't quite as apparent, such as turning off the Mac's Wi-Fi capabilities when it isn't using a wireless network connection. Even when your Mac isn't actively connected to a wireless network, your Mac expends energy searching for available networks to use. Turn off Wi-Fi capabilities from the Wi-Fi menu bar icon or the Network preference pane.

Disconnect peripherals, including any attached memory cards. Even when you're not actively using a device, your Mac checks the various ports for any required service a device may need. Your Mac also supplies power through many of its ports, so disconnecting USB-powered external drives, for example, can extend battery time.