I'm trying to configure my Lenovo on arch linux. The last thing I need to do is get the battery 100% working.

Right now it appears that the main battery's state is unknown:

> acpi -V
Battery 0: Unknown, 97%
Battery 0: design capacity 5849 mAh, last full capacity 5956 mAh = 100%
Battery 1: Charging, 96%, 00:05:50 until charged
Battery 1: design capacity 1861 mAh, last full capacity 1536 mAh = 82%
Adapter 0: on-line
Thermal 0: ok, 43.0 degrees C
Thermal 0: trip point 0 switches to mode critical at temperature 200.0 degrees C
Cooling 0: x86_pkg_temp no state information available
Cooling 1: intel_powerclamp no state information available
Cooling 2: Processor 0 of 10
Cooling 3: Processor 0 of 10
Cooling 4: Processor 0 of 10
Cooling 5: Processor 0 of 10

But if I query the battery directly I get a completely different response:

> cat /sys/class/power_supply/BAT0/status

> cat /sys/class/power_supply/BAT0/uevent

I'm at a complete loss as to what to do here. I have a script reporting battery life that runs off of the output of some of these commands and I would like it to be as complete as possible. Clearly the battery is charging, but why would acpi -V say it's unknown? Does anyone know?

  • 2
    I see roughly the same on my T460s. I think the two batteries take turns charging/discharging; currently my BAT0 is "Charging, 98%, 00:04:52 until charged", and my BAT1 is "Unknown, 79%", according to acpi. Laptop-mode-tools reports "You have a broken battery. Cannot determine actual state", but UPower has a heuristic to determine that the actual state of the battery is "Charging". – Mathias Rav Mar 9 '17 at 14:56
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    If the laptop has only a single battery there are only 2 possible states: "discharging" and "charging" (and, well, "charged 100%"). When a laptop has 2 batteries it may use just one of them, then a state of a second battery would be deemed "unknown" (as it's neither charging nor discharging). I have the same thing happening with my Thinkpad X250 so I presume that's an expected behaviour. – ddnomad Apr 1 at 14:26

While on Arch you could try to install the package tpacpi-bat (A Perl script with ACPI calls for recent ThinkPads (such as T420 and W520) whose battery thresholds are not supported by tp_smapi) with

pacman -S tpacpi-bat

It could help to get it fixed. See info about the configuration here.

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