What do I need to know?

Thanks in part to ever increasing processor efficiency, the battery life of Apple's MacBooks improve with each new model release. However, the battery life of your brand new machine will inevitably start to fade over time, and you’ll find yourself with less working time between charges. It’s worth knowing what conditions could shorten (or even damage) the life of your battery, and it certainly pays to maximise your battery runtime with ‘good practice’ OS settings for your your MacBook, MacBook Air or MacBook Pro.

Know your battery!


There are several routine things you can do to keep an eye on battery health.


Show battery percentage

Monitoring the remaining battery life won't make it last any longer, but it can help you estimate how much work you have before you need to recharge. It can also help you to keep your battery at optimal recommended charge (more of which later). You’ll also notice if your battery’s health suddenly degrades.

If your MacBook shows only the battery icon in the menu bar, click the battery icon in the menu bar, then click Show Percentage.

Check battery condition

To check the condition of your battery, click on the battery icon in the menu bar. You'll see one of four conditions:

  1. Normal: The battery is functioning normally.
  2. Replace Soon: The battery is functioning normally but holds less charge than it did when it was new.
  3. Replace Now: The battery is functioning normally but holds significantly less charge than it did when it was new. You can continue to use the battery until you replace it without harming your computer.
  4. Service Battery: The battery isn't functioning normally, and you may (or may not) notice a change in its behaviour, or the amount of charge it’s holding. Take your computer in for service. You can continue to use your battery before it's checked without harming your computer.

According to Apple, a MacBook battery is designed to retain up to 80 percent of its original capacity at 1,000 complete charge cycles. To check your MacBook's current cycle count, click the Apple icon in the upper-left corner and then select System Report. Next, click Power from the left panel and look for the number for Cycle Count under Health Information.

Activity monitor

Activity Monitor is a very handy app that’s built into the OS of your MacBook.

Go to Applications > Utilities to open it, then click on the Energy tab.

Here, you can see how much energy each of your applications is using. At the bottom of the window you can see the remaining charge, time remaining and time on battery.

‘Time remaining’ is your indication of how many hours you can expect before the battery runs down, and ‘Time on battery’ is how long the laptop has been running on the battery without being plugged in.

You’ve got the power!

Here are the most effective ways to optimise your settings and maximise battery life:

Dim the display

Powering the display is the single biggest drain on your battery resources. The brighter your display, the shorter your battery life.

Go to System Preferences > Displays, then lower the brightness of your display to a level that's comfortable for your eyes. Uncheck the Automatically adjust brightness box.

The Energy Saver preference pane in System Preferences includes several settings that determine power levels for your MacBook. Your MacBook knows when it’s plugged in and runs accordingly. When using battery power, it dims the screen and uses other components sparingly. You can also set the display to dim slightly on battery power, and to shut off display and/or hard disk after a period of inactivity here.

Disable keyboard backlights when not needed

A backlit keyboard may be great for typing in the dark, but it can also rinse your battery.

Go to System Preferences > Keyboard. On the Keyboard tab, check the box for Turn keyboard backlight off after xxx of inactivity. Your options range from 5 seconds to 5 minutes.

Turn off Bluetooth

Bluetooth is something we all leave on by mistake, but it’s another battery hog.

Go to System Preferences > Bluetooth and click the Turn Bluetooth Off button, or easier still, click the Bluetooth icon in the menu bar and choose Turn Bluetooth Off.

Turn off Wi-Fi

Wi-Fi uses power even when not connected to a network. You can turn it off in the Wi-Fi status menu in the menu bar or in System Preferences > Network preferences.

Quit unused applications

You can clearly see on Activity Monitor how certain programs munch through your battery, so if you’re not using it, quit it. Command + Q keys at the same time, or clicking on the program in the top menu bar and selecting the Quit option.


Unplug peripherals when not in use - SD cards, drives, dongles – anything plugged in to a USB port that’s not being used. If the mains power isn't connected, charging your smartphone or tablet via the MacBook's USB port will also drain your battery down.

Use Dark Mode

Switch on Dark Mode as it takes less battery to display black pixels than white ones (Mac OS Mohave or later).

To turn on Dark Mode in Mojave or later:

  1. Open System Preferences.
  2. Click on General.
  3. Click on Dark.

If your Mac OS is earlier than Mohave, you could invert colours to save battery life.

To invert colours:

  1. Open System Preferences.
  2. Click on Accessibility.
  3. Click on Display.
  4. Check the box beside Invert colours.

Stop background activity

  1. Turn off Notifications. Click on System Preferences > Notifications and limit the apps that can check for notifications.
  2. Turn off Mail’s auto check mode. Open Mail > Preferences and change the Check for New Messages tab to Manually.
  3. Turn off Spotlight. Open Spotlight preferences, select the Privacy tab, and drag your Mac's hard drive to the Privacy list.

How to preserve your MacBook battery

Unplug it!

Another mistake we all make. If you leave your MacBook permanently plugged in it will eventually kill the battery. There are a few reasons for this, but the biggest is that the extra heat generated damages the battery.

Don't charge to 100%

Apple recommend charging to only 50% on a regular basis, as storing it at maximum capacity for an extended period can result in a shorter battery life. Also, running the battery consistently into the single-digit percentages can damage the lithium-ion battery in the long run.

Update your software

Apple routinely offers patches and enhancements to macOS that improve battery life, so it’s worth keeping as up to date as possible.

Store your MacBook half-charged when you store it long term.

 Something that I didn’t know until recently. Apple say this:

'If you want to store your device long term, two key factors will affect the overall health of your battery: the environmental temperature and the percentage of charge on the battery when it’s powered down for storage. Therefore, we recommend the following:

  • Do not fully charge or fully discharge your device’s battery — charge it to around 50%. If you store a device when its battery is fully discharged, the battery could fall into a deep discharge state, which renders it incapable of holding a charge. Conversely, if you store it fully charged for an extended period of time, the battery may lose some capacity, leading to shorter battery life.
  • Power down the device to avoid additional battery use.
  • Place your device in a cool, moisture-free environment that’s less than 90° F (32° C).
  • If you plan to store your device for longer than six months, charge it to 50% every six months.

Depending on how long you store your device, it may be in a low-battery state when you remove it from long-term storage. After it’s removed from storage, it may require 20 minutes of charging with the original adapter before you can use it.'

Avoid extreme ambient temperatures

I guess that this one should be obvious….

A MacBook is designed to perform well in a wide range of ambient temperatures, with 62° to 72°F (16° to 22°C) as the ‘ideal’ zone. It’s especially important to avoid exposing your MacBook to ambient temperatures higher than 95° F (35° C), which can permanently damage battery capacity (ie. your battery won’t power your MacBook for as long on a given charge). Charging in high ambient temperatures can damage it further, and software may limit charging above 80% when the recommended battery temperatures are exceeded. Even storing a battery in a hot environment can damage it irreversibly.

Equally, when using a MacBook in a very cold environment, you may notice a decrease in battery life, but this condition is temporary. Once the battery’s temperature returns to its normal operating range, its performance will return to normal.

Incorrect battery information?

It’s happened to me before – the battery claiming it’s on only 60% after a full charge, or showing no charge at all.

Calibrate the battery

This process involves charging the battery, draining it completely and then charging it again. This might sound rudimentary but it’s worthwhile, especially if your battery only ever holds around 50% of its charge. However, it is worth noting that Apple says newer models are pre-calibrated and so this approach won’t work for them. It also might not work for batteries that rarely go above 25% but you can always try and see for yourself.

Apple says on its website: “The battery needs to be recalibrated from time to time to keep the onscreen battery time and percent display accurate and to keep the battery operating at maximum efficiency.”

Reset the System Manager Controller (SMC)

If all else fails, reset the SMC. Like resetting the PRAM, a favourite Mac users go-to.

Resetting the SMC returns the hardware settings to default values, and basically sees the MacBook re-evaluate the battery from scratch, removing the chance that it displays an incorrect status.

To reset the SMC:

  1. Shut down your MacBook.
  2. When shut down, connect the power adapter.
  3. Now hold down Control, Shift, Option/Alt and the Power button for around five seconds.
  4. Release all the keys at the same time.

After resetting the SMC, press the Power button to start up the MacBook.

Thinking of buying a MacBook from new? Think different.

Apple are working hard to reduce their carbon footprint, but computer manufacture is notoriously carbon and rare earth heavy - not to mention the sumptuous packaging!

We all have a part to play in maintaining the environment we live in. By buying a refurbished MacBook we are collectively reducing the overall technology carbon footprint and preserving the planet now and for our future generations. A good refurbished MacBook Pro is both a sound economic and ecological choice.