Collect your laptop’s own battery (Windows)#

The wmi source reads the local Windows laptop or tablet battery through the root\wmi classes — the quickest way to collect real hardware data with no equipment at all.

Install and run#

pip install "battfeed[wmi]"

$ battfeed collect --source wmi --duration 6 --interval 2 --institution SINTEF --cell LaptopMain
Collected 3 sample(s) from 'wmi' in 6.0 s -> SINTEF__LaptopMain__20260811_001.bdf.csv

$ head -4 SINTEF__LaptopMain__20260811_001.bdf.csv
test_time_second,voltage_volt,current_ampere,power_watt
0.09399999992456287,16.59,0.0,0.0
2.1089999999385327,16.59,0.0,0.0
4.155999999959022,16.59,0.0,0.0

That is a genuine reading from the machine these docs were built on: a 4-cell pack at 16.59 V, drawing no battery current because the laptop was on mains power. Unplug the charger and current_ampere goes negative (discharging, per the BDF sign convention); plug it back in mid-charge and it goes positive.

Notes#

  • Windows only, and the machine must actually have a battery — on a desktop the source reports itself unavailable in battfeed sources rather than failing mid-run.

  • Poll gently: the WMI classes update on the order of seconds, so --interval 2 or slower is plenty.

  • For a long-running record of charge/discharge behaviour (for example, profiling your fleet’s laptop packs), combine this with a config file and the unattended-operation recipes — the Windows Task Scheduler recipe there works as-is with --source wmi.

  • Android phones are the same idea over adb: battfeed collect --source android --interval 5, needing only platform-tools on PATH. battfeed discover --source android lists connected devices.