A battery status program for x86-64 Linux laptops in the form of a 384-byte ELF executable.

Usage

$ btry
30.6 Wh / 31.1 Wh (98%)

Sometimes there are no energy_now and energy_full files, but charge_* files instead (at least on my ThinkPad X220). If this is the case, btry prints ampere hours instead of watt hours.

$ btry
2.2 Ah / 2.8 Ah (78%)

Installation

base64 -d <<EOF | unxz -Fraw --lzma2=dict=4K > btry && chmod +x btry
4AF/AUIAAD+R1tX9PhIql6sjxkjsaokIKBWGZx/84juTwnC0Z1zPT1NrX7p18E3d+SYZAoDxhoI6EZaJVYtZPl3R
Q0GmvBz3Jpv7zJ0Mejc8xhxNzv48cldvmf1G7JlbiLQqwNU38t9FmUN0yd7iBvOy1V9kLQfYAQnRBknAjvvoYTTG
30UkkfizhtW6tCsfsG3fEsm3MvG41qzqCrQjm8NMwkiQyGpf/o3Uzf4jIctfUBEL19LAmr9t0cVJTrUCVYy0GW9c
vPd/2izGOtFw/14myD8lseTo0EpXtChauuNLZwgWlTynXkSAK7mP5HXtIyTA7QEWZ7glaptCYfF5ZE38eR+BYZ4B
bMHK3oYqcY0rsWWjSVvpMZpghUEnzQw6cSYuHN5nj0BpdKR/zHyp942jAts/FTHT6GDTu5o15fn8PQP76YOG9UQA
EOF

Limitations

• Anything that's not x86-64 and Linux is definitely not supported.
• I don't know how standard/portable the /sys/class/power_supply/BAT0 path used actually is.
• If neither an energy_full nor a charge_full file exists in /sys/class/power_supply/BAT0, an infinite loop results.
• Extra batteries (like in the ThinkPad T480) are ignored.

Build instructions

Linux on x86-64

make

Other platforms

No.

Notes

When my ThinkPad X220 is plugged in at the time I wake it from suspend mode, I get the charge_now file. When it is not plugged in I get the energy_now file. At least I think that's how it works.