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Asked: 2025-01-16 06:13:14 +0800 CST

Limit laptop battery charging to 80% using TLP on HP EliteBook 840 G6

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I bought this notebook used and am trying to get the most life out of the battery. After installing TLP I tried using this guide to limit charging to 80%. It doesn't work though. Modifying /etc/tlp.conf in the way described so that the line states STOP_CHARGE_THRESH_BAT0=80 (uncommented) has no effect. The battery still charges to 100%. How do I fix that?

power-management

1 Answers

  1. Best Answer

    It may be that tlp's battery care features are not supported for your system. If you check tlp-stat -b, it should either list what features are supported or say "none available". For reference, the tlp docs do not list any HP devices whatsoever, so this feature likely is not available for your system.

    BAT0 is not necessarily the correct battery. It's possible for your only battery to be BAT1 instead of BAT0. You can check your system's batteries here:

    ls /sys/class/power_supply/

    Which should list AC power plus all batteries (probably just one.)

    If your battery is actually labeled BAT1, the intended setting in /etc/tlp.conf would be STOP_CHARGE_THRESH_BAT1=80.

    If that isn't the issue, it could also be a firmware issue per this comment on a similar question, but that also seems to affect systems with multiple or mislabeled batteries specifically.

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