This repository contains an experimental Linux kernel driver for the battery health control WMI interface of Acer laptops. It can be used to control two battery-related features of Acer laptops that Acer provides through the Acer Care Center on Windows: a health mode that limits the battery charge to 80% with the goal of preserving your battery's capacity and a battery calibration mode which puts your battery through a controlled charge-discharge cycle to provide more accurate battery capacity estimates.

So far the driver has been reported to work on an Acer Swift 3 (SF314-34), an Acer Aspire 5 A515-45G-R5A1, and an Acer Enduro N3 Urban (EUN314A-51W). Any feedback on how it works on other Acer laptops would be appreciated.

Make sure that you have the kernel headers for your kernel installed and type make KERNELVERSION=$(uname -r) in the cloned project directory. In more detail, on a Debian or Ubuntu system, you can build by:

sudo apt install build-essential linux-headers-$(uname -r) git
git clone https://github.com/frederik-h/acer-wmi-battery.git
cd acer-wmi-battery
make KERNELVERSION=$(uname -r)

Loading the module without any parameters does not change any health or calibration mode settings of your system:

sudo insmod acer-wmi-battery.ko

The charge limit can then be enabled as follows:

echo 1 | sudo tee /sys/bus/wmi/drivers/acer-wmi-battery/health_mode

Alternatively, you can enable it at module initialization time:

sudo insmod acer-wmi-battery.ko enable_health_mode=1

Before attempting the battery calibration, connect your laptop to a power supply. The calibration mode can be started as follows:

echo 1 | sudo tee /sys/bus/wmi/drivers/acer-wmi-battery/calibration_mode

The calibration disables health mode and charges to 100%. Then it discharges and recharges the battery once. This can take a long time and for accurate capacity estimates the laptop should not be used during this process. After the discharge-charge cycle the calibration mode should be manually disabled since the WMI event that indicates the completion of the calibration is not yet handled by the module:

echo 0 | sudo tee /sys/bus/wmi/drivers/acer-wmi-battery/calibration_mode

If you found this driver to be working on your laptop, you may want to install it into your system for ease of use.

1. Install DKMS and generic kernel headers (this will always get you the latest headers), on Debian or Ubuntu it can be done with:

sudo apt install dkms linux-headers-generic

2. Install the driver: in the cloned project directory execute:

chmod +x install.sh uninstall.sh
sudo ./install.sh

The driver will now automatically load at boot and be recompiled after a kernel upgrade. Reboot to use it.

In the cloned project directory execute:

sudo ./uninstall.sh

There exists another driver with similar functionality of which I have not been aware when starting the work on this driver. See this issue for discussion.