How to check Battery Health and improve battery runtime on Mac
Posted on November 20 2020
Battery life is a function of capacity and usage, the higher the capacity the longer the battery runtime but the higher the usage the shorter the battery runtime. A user that has a healthy battery with a large capacity can experience lower than expected battery runtime if they are running demanding programs (Chrome, Adobe, Logic Pro, Final Cut etc) or have the display brightness at 100% for example.
In order to talk about some of the technicalities of batteries it is helpful to explain a few of the key terms that Apple use,
- Cycle count: Batteries are expected to function for a certain number of cycles. This number represents the sum of total and partial discharge cycles throughout the life of the battery.
- Full charge capacity: Measured in mAH (milliampere-hours), this refers to the amount of power the battery is capable of containing, less the energy required to shut down the device. This number lowers as the battery becomes depleted with usage and age.
- Load: The amount of activity being performed by a task or tasks. Certain power-intensive processes place a heavier load on the battery and result in a much-reduced runtime per charge.
The capacity of a battery is how much charge it can hold. When new, a battery should hold 99-100% of its full charge capacity. Over time the full charge capacity will naturally reduce as a result of use and increasing number of charge cycles. Apple advise that their batteries should last 1000 charging cycles before the full charge capacity deteriorates significantly.
The full charge capacity and charge cycle count can be checked on a Mac by clicking the Apple sign top left, About This Mac, System Report… then referencing the Power row in the nested Hardware menu.
There is also a handy third party tool called Coconut Battery that displays battery information more clearly and provides some more information. Coconut battery displays the current full charge capacity as a percentage of it’s designed full charge capacity (the capacity when new).
Using programs that are demanding will reduce battery runtime significantly. During testing we found that running a Zoom call with four participants reduced the battery life of a 16-inch MacBook Pro to less than 3 hours. This is a large drop from Apple’s advertised figure of 11 hours for this model. In real world usage Apple’s battery life figures are difficult to obtain, however this shows how a seemingly basic app can have a significant effect on battery runtime.
macOS Big Sur introduces a new tool to check on Battery usage that is found in System Preferences.
The System Preferences Battery pane allows you seen see how quickly the battery is being depleted of charge over 24 hours and 10 days. This however does not tell you exactly what is causing the battery charge to deplete.
In order to see which apps or processes are loading the battery you can click the battery icon on the menu bar, this will advise which apps are “Using Significant Energy”.
This is a live view of what apps are depleting battery life, but what if the offending app has already been closed and you want to see if it was the culprit? Another tool called Activity Monitor will allow you to see some more detail. To open Activity Monitor click the Spotlight icon in the menu bar, type in Activity Monitor and open the app. Once opened select the Energy tab and order descending the 12 hr Power column descending by clicking beside it.
This will show you which apps or processes have been having the largest effect on battery drain over the last 12 hours of usage, the higher the score the more load it is placing on the battery. Closing these apps will reduce load on the battery and increase run time.
Common culprits of higher than usual battery loads are Chrome, Zoom, Adobe suite (Premiere Pro, Photoshop, Illustrator etc) and Final Cut Pro. Activities such as streaming video, playing music through the internal speakers and having external peripherals plugged in contribute to battery load. System settings such as display brightness and when the display sleeps also have a significant impact.
Using the streamlined and efficient Safari over Chrome (the legendary Walt Mossberg has an opinion on this!), keeping the display backlight to a more moderate level and limiting demanding app usage whilst on battery power will all contribute to maximising battery runtime.
At Hoxton Macs, all devices are checked to ensure all batteries have below 500 battery cycles and the full charge capacity is above 80% prior to sale to ensure battery runtime is not going to affect your productivity on the go!