Laptop power & battery

Laptop shuts down immediately when unplugged even at high battery percentage

This strongly suggests the battery can't actually hold or deliver charge despite what the percentage shows, which usually means it needs recalibration or replacement.

Difficulty
Easy
Time
30–90 minutes (includes discharge/charge cycle)
DIY cost
$0–$100
Pro cost
$80–$180

Symptoms

  • Laptop reads 50–100% battery but dies instantly when the charger is removed
  • Laptop only ever runs while plugged directly into power
  • Removing the charger causes an immediate shutdown, not a graceful low-battery warning
  • Problem happens no matter what task is running

Likely causes

  • CommonBattery has failed and can no longer hold or supply charge despite showing a percentageA dead or dying battery can still report a percentage via software while being physically unable to power the laptop.
  • CommonBattery gauge severely miscalibratedSoftware may show a false high percentage that doesn't reflect real capacity.
  • PossibleLoose or failed internal battery connectorA poor connection can allow charging but fail the moment AC power is removed.
  • Less commonBattery has been removed or is not installed at allWorth double-checking on laptops with a removable battery.

What to do

  1. Confirm the battery is actually installed and seated if it's a removable-battery laptop.
  2. Run a full discharge-to-shutoff and recharge-to-100% cycle to try recalibrating the gauge.
  3. Check battery health/condition in system settings for a report on actual remaining capacity.
  4. Note whether the shutdown is instant (points to a dead/disconnected battery) versus a quick but not instant drain (points to severe degradation).
  5. If a removable battery, reseat it firmly and test again.
  6. If recalibration doesn't change the behavior, treat the battery as failed and plan for replacement.

Tools and parts

  • None required
Replacement laptop batterySearch: “[laptop model] replacement battery”

When to call a pro

If the laptop still dies instantly when unplugged after recalibration, have the battery professionally tested and replaced.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.