This tool makes it possible to keep a chronically plugged in M1 Macbook at 80% battery, since that will prolong the longevity of the battery. It is free and open-source and will remain that way.

Want to know if this tool does anything or is just a placebo? Read this excellent article. TL;DR: keep your battery cool, keep it at 80% when plugged in, and discharge it as shallowly as feasible.

Requirements

This is an app for M1 Macs. It will not work on non-M1 macs. Do you have an older Mac? Consider the free version of the Al Dente software package. It is a good alternative and has a premium version with many more features.

Installation

Option 1: install through brew with brew install battery
Option 2: You can download the latest app dmg version here.
Option 3: command-line only installation (see section below)

The first time you open the app, it will ask for your administator password so it can install the needed components. Please note that the app:

Discharges your battery until it reaches 80%, even when plugged in
Disables charging when your battery is above 80% charged
Enabled charging when your battery is under 80% charged
Keeps the limit engaged even after rebooting
Keeps the limit engaged even after closing the tray app
Also automatically installs the battery command line tool. If you want a custom charging percentage, the CLI is the only way to do that.

Do you have questions, comments, or feature requests? Open an issue here or Tweet at me.

🖥 Command-line version

If you don't know what a "command line" is, ignore this section. You don't need it.

The GUI app uses a command line tool under the hood. Installing the GUI automatically installs the CLI as well. You can also separately install the CLI.

The CLI is used for managing the battery charging status for M1 Macs. Can be used to enable/disable the Macbook from charging the battery when plugged into power.

Installation

One-line installation:

curl -s https://raw.githubusercontent.com/actuallymentor/battery/main/setup.sh | bash

This will:

Compile the smc tool from the hholtmann/smcFanControl repository
Install smc to /usr/local/bin
Install battery to /usr/local/bin

Usage

Example usage:

# This will enable charging when your battery dips under 80, and disable it when it exceeds 80
battery maintain 80

After running a command like battery charging off you can verify the change visually by looking at the battery icon:

After running battery charging on you will see it change to this:

For help, run battery without parameters:

Battery CLI utility v1.0.1

Usage:

  battery status
    output battery SMC status, % and time remaining

  battery maintain LEVEL[1-100,stop]
    reboot-persistent battery level maintenance: turn off charging above, and on below a certain value
    eg: battery maintain 80
    eg: battery maintain stop

  battery charging SETTING[on/off]
    manually set the battery to (not) charge
    eg: battery charging on

  battery adapter SETTING[on/off]
    manually set the adapter to (not) charge even when plugged in
    eg: battery adapter off

  battery charge LEVEL[1-100]
    charge the battery to a certain percentage, and disable charging when that percentage is reached
    eg: battery charge 90

  battery discharge LEVEL[1-100]
    block power input from the adapter until battery falls to this level
    eg: battery discharge 90

  battery visudo
    instructions on how to make which utility exempt from sudo, highly recommended

  battery update
    update the battery utility to the latest version

  battery reinstall
    reinstall the battery utility to the latest version (reruns the installation script)

  battery uninstall
    enable charging, remove the smc tool, and the battery script

Why does this exist?

I was looking at the Al Dente software package for battery limiting, but I found the license too limiting for a poweruser like myself.

I would actually have preferred using Al Dente, but decided to create a command-line utility to replace it as a side-project on holiday. A colleague mentioned they would like a GUI, so I spend a few evenings setting up an Electron app. And voila, here we are.

"It's not working"

If you used one of the earlier versions of the battery utility, you may run into path/permission issues. This is not your fault but mine. To fix it:

sudo rm -rf ~/.battery
binfolder=/usr/local/bin
sudo rm -v "$binfolder/smc" "$binfolder/battery"

Then reopen the app and things should work. If not, open an issue and I'll try to help you fix it.