Patches to the Linux kernel that allow setting battery charge thresholds on Intel Apple devices.

This includes a TLP script for use with that system. The file should be placed at /usr/share/tlp/bat.d/45-apple. Otherwise the interface can be accessed directly via sysfs:

/sys/class/power_supply/BAT0/charge_control_end_threshold
/sys/class/power_supply/BAT0/charge_control_full_threshold
/sys/class/power_supply/BAT0/charge_control_start_threshold

Note charge_control_start_threshold is not currently implemented.

Example:

# echo 80 > /sys/class/power_supply/BAT0/charge_control_end_threshold

This will cause charging to stop at 80% charge. Note this change is persistent across power cycles and operating systems unless the SMC is reset.

Setting charge_control_full_threshold controls when the charging LED turns green and is cosmetic only. Generally it doesn't need to be set.

Note that for charge_control_full_threshold to work it needs to be set to a value less than than the end threshold because the battery will tend to float slightly under the maximum. Subtract at least 2% or more from the end threshold.

Arch Linux AUR package

To build on other distributions install the dkms package then run something like the following:

#!/bin/sh
TAG="$(git ls-remote --tags https://github.com/c---/applesmc-next | grep -oP 'tags/\K[0-9.]+' | tail -n1)"
git clone --depth 1 --branch "$TAG" https://github.com/c---/applesmc-next "/usr/src/applesmc-next-$TAG"
dkms install "applesmc-next/$TAG"