# Plot battery capacity over time
$ crontab -l
# m h  dom mon dow   command
*   *   *   *   *   (date; date +date=\%s; cat /sys/class/power_supply/BAT0/uevent) >> .battery-samples
$ grep -a FULL= ~/.battery-samples | grep -Po '\d+' | gnuplot -p -e "plot '-' with linespoints"