Public bug reported:
## Ubuntu version
Ubuntu Server 26.04 LTS
## Hardware
Laptop:
Dell Inspiron 5559
Battery:
Vendor: LGC-LGC2.80
Model: DELL 991XP55
CPU/GPU platform:
Intel Skylake-U (6th Gen Core)
## Problem
The Linux power_supply interface reports an impossible battery capacity
value above 100%.
The battery exposes:
POWER_SUPPLY_CAPACITY=127
The raw battery values are:
POWER_SUPPLY_CHARGE_FULL_DESIGN=2200000
POWER_SUPPLY_CHARGE_FULL=1731000
POWER_SUPPLY_CHARGE_NOW=2200000
The reported values are inconsistent:
POWER_SUPPLY_CHARGE_NOW / POWER_SUPPLY_CHARGE_FULL * 100 results in
approximately 127%, which suggests that either the firmware is reporting
incorrect battery values or the kernel is not validating the values
before exposing them.
A battery capacity above 100% appears to be invalid.
## Expected behavior
The kernel power_supply interface should either:
- prevent battery capacity values above 100%, or
- report a warning when inconsistent battery values are returned by firmware.
## Actual behavior
The system exposes:
POWER_SUPPLY_CAPACITY=127
through:
/sys/class/power_supply/BAT0/uevent
## Additional information
The battery threshold functionality works correctly.
The system reports:
charge-start-threshold: 75%
charge-end-threshold: 80%
charge-threshold-supported: yes
from:
upower -i $(upower -e | grep BAT)
UPower displays:
percentage: 100%
so the issue appears to be limited to the raw power_supply values.
It is unclear whether this originates from Dell firmware/ACPI reporting
or kernel power_supply handling.
## Reproduction
Run:
cat /sys/class/power_supply/BAT0/uevent
Observed:
POWER_SUPPLY_CHARGE_NOW=2200000
POWER_SUPPLY_CHARGE_FULL=1731000
POWER_SUPPLY_CAPACITY=127
## System information
Kernel version:
Linux home 7.0.0-28-generic #28-Ubuntu SMP PREEMPT_DYNAMIC Sun Jun 21 01:01:36
UTC 2026 x86_64 GNU/Linux
BIOS version:
1.7.0
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-28-generic 7.0.0-28.28
ProcVersionSignature: Ubuntu 7.0.0-28.28-generic 7.0.12
Uname: Linux 7.0.0-28-generic x86_64
NonfreeKernelModules: zfs
AlsaVersion: Advanced Linux Sound Architecture Driver Version k7.0.0-28-generic.
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path',
'/dev/snd/controlC0', '/dev/snd/hwC0D2', '/dev/snd/hwC0D0',
'/dev/snd/pcmC0D8p', '/dev/snd/pcmC0D7p', '/dev/snd/pcmC0D3p',
'/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/seq', '/dev/snd/timer']
failed with exit code 1:
Card0.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer'
Card0.Amixer.values: Error: [Errno 2] No such file or directory: 'amixer'
CasperMD5CheckResult: pass
CurrentDmesg: Error: command ['dmesg'] failed with exit code 1: dmesg: read
kernel buffer failed: Operation not permitted
Date: Tue Jul 28 18:26:18 2026
InstallationDate: Installed on 2026-07-18 (10 days ago)
InstallationMedia: Ubuntu-Server 26.04 "Resolute Raccoon" - Release amd64
(20260420.1)
Lsusb:
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card
Reader Controller
Bus 001 Device 003: ID 8087:07dc Intel Corp. Bluetooth wireless interface
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Lsusb-t:
/: Bus 001.Port 001: Dev 001, Class=root_hub, Driver=xhci_hcd/12p, 480M
|__ Port 006: Dev 002, If 0, Class=Vendor Specific Class, Driver=rtsx_usb,
480M
|__ Port 008: Dev 003, If 0, Class=Wireless, Driver=btusb, 12M
|__ Port 008: Dev 003, If 1, Class=Wireless, Driver=btusb, 12M
/: Bus 002.Port 001: Dev 001, Class=root_hub, Driver=xhci_hcd/6p, 5000M
MachineType: Dell Inc. Inspiron 5559
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-28-generic
root=UUID=53ace6c3-489a-422a-9820-ed2a8ba9b143 ro
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
RebootRequiredPkgs: Error: path contained symlinks.
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
acpidump:
dmi.bios.date: 05/10/2019
dmi.bios.release: 1.7
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.7.0
dmi.board.name: 07JM0H
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias:
dmi:bvnDellInc.:bvr1.7.0:bd05/10/2019:br1.7:svnDellInc.:pnInspiron5559:pvr:rvnDellInc.:rn07JM0H:rvrA00:cvnDellInc.:ct10:cvr:sku06B2:pfaInspiron:
dmi.product.family: Inspiron
dmi.product.name: Inspiron 5559
dmi.product.sku: 06B2
dmi.sys.vendor: Dell Inc.
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: acpi amd64 apport-bug battery resolute
** Attachment added: "bugreport-attachments.tar.gz"
https://bugs.launchpad.net/bugs/2162005/+attachment/5987439/+files/bugreport-attachments.tar.gz
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https://bugs.launchpad.net/bugs/2162005
Title:
Dell Inspiron 5559 battery reports impossible capacity above 100%
through power_supply interface
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