battery-monitor

A simple script to plot a live graph of laptop power consumption based on battery reports.

Data is captured via cat /sys/class/power_supply/BAT*/power_now. Multiple-battery setup is suported. In tiling wm setups, it's better to make the graph window floating, sticky and small.

Useful for cases when you want to be mindful of what particular situations or programs increase power consumption. For example in the screencast above, the laptop was on battery for a while, then we see a power surge which was due to running a computing-intensive program.

On the tray icon hovering, the tooltip shows wattage, right-click to quit the script.

Dependencies

• feedgnuplot : plots data stream
• libvnlog-perl
• yad : tray icon

In a Debian-like distro:

sudo apt install feedgnuplot libvnlog-perl
# yad needs to be built from master, tested with (v14.1)

Usage

Check battery-monitor -h:

$ battery-monitor -h
Usage: battery-monitor [-t PERIOD] [-w WIDTH] [-V] [-h]
DESCRIPTION
    Plot power consumption [Watt] of batteries

OPTIONS
    [-t PERIOD] :
        Sampling period in seconds
        Default: 1
    [-w WIDTH] :
        Graph window width in seconds
        Default: 30
    [-V] :
        Print version
    [-h] :
        Display the help message

EXAMPLES
    # graph power consumption wattage for sampling period of 0.5 seconds and
    # window of 4 seconds
    battery-monitor -t 0.5 -w 4

Development

• linter: shellcheck
• formatter: shfmt -i 4 -bn -ci -sr