Laptop won't boot unless plugged in

Hello! My T480 has both batteries on 75% health, it used to only boot up if the battery was above 50% charged, now it just won’t do at all until i plug the charger. I’m running endeavour os, so i’m unsure if it might be a hardware or os problem, help:(

Unless it starts shutting down after it is already booted, it is hardware/firmware/BIOS issue.

It does shut down right after the eos black book screen:( i really dont know how to trouble shoot either

I would look at BIOS/UEFI settings that may be affecting it but also would not know how to proceed after exhausting this

Might just need a BIOS/firmware update.

What is the output of: inxi -Fxxc0z

If it is BIOS needing updated, see here: T480 BIOS

Hi! Thank you for the help, this is said command’s output;

System: 
  Kernel: 7.1.5-arch1-2 arch: x86_64 bits: 64 compiler: gcc v: 16.1.1 
  Desktop: KDE Plasma v: 6.7.3 tk: Qt v: N/A wm: kwin_wayland dm: N/A 
    Distro: EndeavourOS base: Arch Linux 
Machine: 
  Type: Laptop System: LENOVO product: 20L6S91F00 v: ThinkPad T480 
    serial: <superuser required> Chassis: type: 10 serial: <superuser required> 
  Mobo: LENOVO model: 20L6S91F00 v: SDK0J40697 WIN 
    serial: <superuser required> 
    part-nu: LENOVO_MT_20L6_BU_Think_FM_ThinkPad T480 Firmware: UEFI 
    vendor: LENOVO v: N24ET81W (1.56 ) date: 09/06/2025 
Battery: 
  ID-1: BAT0 charge: 16.2 Wh (91.9%) condition: 17.7/24 Wh (73.7%) 
    volts: 12.29 min: 11.46 model: LGC 01AV489 serial: <filter> charging: 
    status: not charging control: start: 0% end: 100% cycles: 143 
  ID-2: BAT1 charge: 1.6 Wh (9%) condition: 18/24 Wh (75%) volts: 12.45 
    min: 11.46 model: SMP 01AV452 serial: <filter> charging: status: charging 
    control: start: 0% end: 100% cycles: 338 
CPU: 
  Info: quad core model: Intel Core i7-8650U bits: 64 type: MT MCP 
    arch: Coffee Lake rev: A cache: L1: 256 KiB L2: 1024 KiB L3: 8 MiB 
  Speed (MHz): avg: 400 min/max: 400/4200 cores: 1: 400 2: 400 3: 400 4: 400 
    5: 400 6: 400 7: 400 8: 400 bogomips: 33599 
  Flags-basic: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx 
Graphics: 
  Device-1: Intel Kaby Lake-R GT2 [UHD Graphics 620] 
    vendor: Lenovo ThinkPad T480 driver: i915 v: kernel arch: Gen-9.5 ports: 
    active: eDP-1 empty: DP-1, DP-2, HDMI-A-1, HDMI-A-2 bus-ID: 00:02.0 
    chip-ID: 8086:5917 
  Device-2: IMC Networks Integrated Camera driver: uvcvideo type: USB 
    rev: 2.0 speed: 480 Mb/s lanes: 1 bus-ID: 1-8:4 chip-ID: 13d3:56a6 
  Display: wayland server: X.org v: 1.21.1.24 with: Xwayland v: 24.1.13 
    compositor: kwin_wayland driver: gpu: i915 display-ID: 0 
  Monitor-1: eDP-1 model: ChiMei InnoLux 0x14c9 res: 1920x1080 hz: 60 
    dpi: 158 diag: 354mm (13.9") 
  API: EGL v: 1.5 platforms: device: 0 drv: iris device: 1 drv: swrast gbm: 
    drv: iris surfaceless: drv: iris wayland: drv: iris x11: drv: iris 
  API: OpenGL v: 4.6 vendor: intel mesa v: 26.1.6-arch1.1 glx-v: 1.4 
    direct-render: yes renderer: Mesa Intel UHD Graphics 620 (KBL GT2) 
    device-ID: 8086:5917 display-ID: :0.0 
  API: Vulkan v: 1.4.357 surfaces: N/A device: 0 type: integrated-gpu 
    driver: mesa intel device-ID: 8086:5917 
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo 
    de: kscreen-console,kscreen-doctor wl: wayland-info 
    x11: xdpyinfo, xprop, xrandr 
Audio: 
  Device-1: Intel Sunrise Point-LP HD Audio vendor: Lenovo ThinkPad T480 
    driver: snd_hda_intel v: kernel bus-ID: 00:1f.3 chip-ID: 8086:9d71 
  API: ALSA v: k7.1.5-arch1-2 status: kernel-api 
  Server-1: sndiod v: N/A status: off 
  Server-2: PipeWire v: 1.6.8 status: active with: 1: pipewire-pulse 
    status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin 
    4: pw-jack type: plugin 
Network: 
  Device-1: Intel Ethernet I219-LM vendor: Lenovo driver: e1000e v: kernel 
    port: N/A bus-ID: 00:1f.6 chip-ID: 8086:15d7 
  IF: enp0s31f6 state: down mac: <filter> 
  Device-2: Intel Wireless 8265 / 8275 driver: iwlwifi v: kernel pcie: 
    speed: 2.5 GT/s lanes: 1 bus-ID: 03:00.0 chip-ID: 8086:24fd 
  IF: wlan0 state: up mac: <filter> 
Bluetooth: 
  Device-1: Intel Bluetooth wireless interface driver: btusb v: 0.8 type: USB 
    rev: 2.0 speed: 12 Mb/s lanes: 1 bus-ID: 1-7:3 chip-ID: 8087:0a2b 
  Report: btmgmt ID: hci0 rfk-id: 1 state: up address: <filter> bt-v: 4.2 
    lmp-v: 8 
Drives: 
  Local Storage: total: 476.94 GiB used: 24.85 GiB (5.2%) 
  ID-1: /dev/nvme0n1 vendor: Western Digital model: PC SN720 
    SDAQNTW-512G-1001 size: 476.94 GiB speed: 31.6 Gb/s lanes: 4 
    serial: <filter> temp: 44.9 C 
Partition: 
  ID-1: / size: 474.94 GiB used: 24.85 GiB (5.2%) fs: btrfs 
    dev: /dev/nvme0n1p2 
  ID-2: /boot/efi size: 2 GiB used: 664 KiB (0.0%) fs: vfat 
    dev: /dev/nvme0n1p1 
  ID-3: /home size: 474.94 GiB used: 24.85 GiB (5.2%) fs: btrfs 
    dev: /dev/nvme0n1p2 
  ID-4: /var/log size: 474.94 GiB used: 24.85 GiB (5.2%) fs: btrfs 
    dev: /dev/nvme0n1p2 
Swap: 
  Alert: No swap data was found. 
Sensors: 
  System Temperatures: cpu: 39.0 C pch: 28.5 C mobo: N/A 
  Fan Speeds (rpm): N/A 
Info: 
  Memory: total: 16 GiB note: est. available: 15.36 GiB used: 2.43 GiB (15.8%) 
  Processes: 269 Power: uptime: 2m wakeups: 0 Init: systemd v: 261 
    default: graphical 
  Packages: pm: pacman pkgs: 1229 Compilers: gcc: 16.1.1 Shell: Bash 
    v: 5.3.15 running-in: konsole inxi: 3.3.41

@aruan
If your Lenovo ThinkPad T480 shuts down immediately on boot or displays a black screen, it is often caused by a temporary static charge, a drained or disconnected internal battery, or a stuck CMOS/BIOS state. Try using the emergency reset hole or a hard power drain.

  1. Unplug the charger and all external accessories or USB devices from the laptop.

  2. Locate the emergency reset hole on the bottom cover of your ThinkPad T480 (a tiny pinhole labeled with a curved arrow icon near the screw area).

  3. Insert a straightened paperclip into the pinhole, press and hold the internal button for about 10 seconds.

  4. If that does not work, press and hold the power button down for 30 seconds continuously to drain residual power from the motherboard.

  5. Plug the official charger back in and try to power it on normally.

If the laptop works perfectly with the power adapter, but not at all when off battery, then you might have some issues:

  • The Charge points.
  • The Charging system.
  • Damage to the battery connectors or system board.

Something might be impeding checking the battery state.

This shows you how to dissemble the laptop to access the external and internal batteries:

This is not Linux issue as you will have the problem right away when you press the power button.