inaccurate battery status reporting

[Steve Langasek]

My laptop is plugged into main power most of the time, but as I'm currently travelling, it's connected a lot more intermittently right now. So I don't know when this problem started. But I noticed my desktop indicator was reporting 9% charge and that the battery was not being charged. Disconnecting and reconnecting the power did not change this. Suspending and resuming did not change this. But after rebooting, the desktop was CORRECTLY showing that the battery was at 100% capacity.

The problem seems to be wrong values being reported in /sys from the kernel:

$ cat /sys/class/power_supply/BAT0/charge_{full,full_design,now}
170300000
328720000
65330000
$

The charge_now value is, TTBOMK, correct. But the charge_full value is NOT and appears to change over time?

So now my laptop which has been plugged in over night is reported to be at 38% battery.

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-image-6.8.0-35-generic 6.8.0-35.35+1
ProcVersionSignature: Ubuntu 6.8.0-35.35-generic 6.8.4
Uname: Linux 6.8.0-35-generic x86_64
NonfreeKernelModules: zfs
ApportVersion: 2.28.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/seq: vorlon 9164 F.... pipewire
 /dev/snd/controlC0: vorlon 9168 F.... wireplumber
 /dev/snd/controlC1: vorlon 9168 F.... wireplumber
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Wed Jun 26 08:57:50 2024
InstallationDate: Installed on 2019-12-23 (1646 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
MachineType: LENOVO 20QVCTO1WW
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/BOOT/ubuntu_di672m@/vmlinuz-6.8.0-35-generic root=ZFS=rpool/ROOT/ubuntu_di672m ro quiet splash intel_iommu=off vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-6.8.0-35-generic N/A
 linux-backports-modules-6.8.0-35-generic N/A
 linux-firmware 20240318.git3b128b60-0ubuntu2.1
SourcePackage: linux
UpgradeStatus: Upgraded to noble on 2024-05-22 (34 days ago)
dmi.bios.date: 04/28/2021
dmi.bios.release: 1.39
dmi.bios.vendor: LENOVO
dmi.bios.version: N2OET52W (1.39 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20QVCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0R32862 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.22
dmi.modalias: dmi:bvnLENOVO:bvrN2OET52W(1.39):bd04/28/2021:br1.39:efr1.22:svnLENOVO:pn20QVCTO1WW:pvrThinkPadX1Extreme2nd:rvnLENOVO:rn20QVCTO1WW:rvrSDK0R32862WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_20QV_BU_Think_FM_ThinkPadX1Extreme2nd:
dmi.product.family: ThinkPad X1 Extreme 2nd
dmi.product.name: 20QVCTO1WW
dmi.product.sku: LENOVO_MT_20QV_BU_Think_FM_ThinkPad X1 Extreme 2nd
dmi.product.version: ThinkPad X1 Extreme 2nd
dmi.sys.vendor: LENOVO
modified.conffile..etc.apport.crashdb.conf: [modified]
mtime.conffile..etc.apport.crashdb.conf: 2024-05-24T01:12:43.275502