How to calibrate the battery on your MacBook

The battery on your MacBook, MacBook Air, or MacBook Pro isn’t like any other battery. It’s a highly sophisticated piece of equipment that learns how you use your Mac to decide how and when to charge when the Mac is plugged into power. It can also work out how long it has left before it runs out of charge, based on your current usage. All that is only possible, however, when it’s properly calibrated. When your Mac is new, the battery is calibrated, but as you use it, it drifts out of sync and would benefit from being re-calibrated. In this article, we’ll show you how to do that.

Why calibrate the battery on your MacBook?

Click the battery menu, and you’ll see an indication of how many hours and minutes you have left before your Mac’s battery runs out of charge. Or go to System Preferences, click Battery and take a look at the options. But, of course, all that information and customization is only accurate if the battery is calibrated correctly. But, then, wait not, the information may be incorrect, and the customization options won’t work as you expect. You may even find your Mac’s battery is suddenly depleted when you thought you had plenty of time left before you needed to charge it.

Macbook battery settings

How to calibrate your Mac’s battery

On newer MacBook Airs and MacBook Pros, calibration happens automatically. All you have to do is occasionally allow the battery to run down to zero and power off your Mac. Then power it back on and let it charge to 100%. The battery will recalibrate. On older models, the process is a bit more involved.

  • Fully charge your MacBook’s battery while you’re not using it. Then, wait until the light on the MagSafe connector has turned green before you open the lid and start using it.
  • Once it’s charged, start using your Mac while it’s still plugged into AC power. Use it for two hours like that.
  • When two hours have passed, unplug your MacBook from mains power. Then, keep using it while it runs on battery power until you get a warning telling you that power is running low and that you should save your work.
  • When you see the warning, save your work and keep using your Mac – save work at regular intervals, if the app you’re using doesn’t do that automatically – until it goes to sleep. When it goes to sleep, hold down the power button to turn it off.
  • Wait at least five hours after you turn your Mac off and then plug it into the mains again. Then, wait for it to recharge fully. The battery will now have re-calibrated. The information you see in the battery menu bar item and System Preferences will be accurate.

How to reduce the battery power your Mac uses

You can do several things to reduce the power your Mac uses, and so preserve battery life. The first thing you should do is pay a visit to the Battery pane System Preferences (or Energy Saver in pre-Big Sur versions of macOS). Use the options there to lower screen brightness when your Mac runs on battery power and make the display sleep more quickly.

Here are a few other things you can do:

1. Disconnect peripherals you’re not using

    If you have an external hard drive or USB stick plugged into your Mac, and it doesn’t have its own power source, your Mac provides the power. And if your Mac isn’t plugged into the mains, that power is coming from the battery. The same is true for USB microphones, webcams, and even memos cards.

    2. Close browser tabs

    Every browser tab you have open consumes CPU cycles. And that means it uses energy. If you have dozens of tabs open, that can mount up and put significant pressure on your battery.

    3. Use the battery menu bar item to identify greedy apps

    Click the battery menu bar item, and you’ll see it displays apps that are using significant battery power. If you’re not using the apps shown, quit them. And even if you are, it’s worth restarting them if they have hung or another problem is causing them to use lots of energy.

    Battery draining apps

    4. Get rid of unnecessary login items and launch agents

    Apps and processes that launch when your Mac boots run in the background and consume energy. If you don’t need them, you should get rid of them. Read on to find out how to do that easily.

    The simplest way to remove login items and launch agents is to use CleanMyMac X’s Optimisation module.

    CleanMyMac X - Launch Agents

    1. Download CleanMyMac X and install it, then launch it.
    2. Choose Optimization in the sidebar.
    3. Select View All Items.
    4. Check the boxes next to Login Items and Launch Agents and press Remove.

    Once it’s finished, all login items and launch agents will have been removed. CleanMyMac X can also uninstall applications you don’t need. Alternatively, it can reset them to their default state, if they have started to misbehave and use too much energy.

    Your Mac’s battery is intelligent. It can tell you how long it has left before it’s out of charge and can even optimize its charging schedule based on how you use your Mac. That means it doesn’t charge beyond 80% until you need to use your Mac on battery power, extending the battery’s life. However, to do all of that, it needs to be calibrated, and occasionally that might involve stepping in to calibrate it manually. Follow the steps above to do that and keep your Mac’s battery in top condition for as long as possible.