Limit laptop battery charging at home, full charge elsewhere

README.md

Limit laptop battery charging at home

Lithium batteries wear more quickly when fully charged but of course you need the capacity on the move. Here's a solution: When at home, charge to 85% and 100% when not connected to your home network (wired or wireless).

Pre-requirements: Linux, NetworkManager

Installation

Place the following file under /etc/NetworkManager/dispatcher.d. Edit the network name list on line 7 to match your needs. Examples are Foonet and Barnet. See possible network names by running:

nmcli -t -f name connection show

Also, double-check the sysfs path to your battery. In most cases it's /sys/class/power_supply/BAT0/.

Finally, make sure file is executable and owned by root (chmod +x and chown root:root).

limit-charge

#!/bin/sh -eu

case "${2-}" in
    up|down)
	# Avoid double bookkeeping which connections are up or down,
	# so just check it here.
	if nmcli --terse --fields name connection show --active | grep -qE '^Foonet$|^Barnet$'; then
	    # Home, avoid wearing of the battery
	    charge=85
	else
	    # Away, maximum charge
	    charge=100
	fi
	echo "$charge" > /sys/class/power_supply/BAT0/charge_control_end_threshold
	;;
esac