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Recalibrating laptop batteries

Introduction

If your laptop battery is older or reporting incorrectly, it may be possible to recalibrate the battery. This can correct the reported capacity or battery gauge to extend the life of the battery.

IMPORTANT: Recalibration does not save worn out batteries - it ONLY corrects the capacity. There is no way to recover a worn out battery, but the situation can be temporarily improved.

For help understanding what calibration is, why it’s important, and how to calibrate batteries in other types of devices, check out the Battery Calibration Wiki.

Guide notes

  • If your battery exceeds 30-40 °C (86-104 °F), REPLACE THE BATTERY!
  • You will likely see a capacity decrease. This is good - not bad.
  • Try to avoid using your laptop while it is charging. This may affect calibration accuracy.
  • Inconsistent reporting may indicate the battery is EOL. This can be delayed with proper care, but not reversed.
  • If your battery is older, consider a ~10% discharge. A full discharge may cause damage.

How to recalibrate the battery

  • Charge the laptop to 100%. Use it until it shuts down and no longer turns on.
    • See BIOS lockouts and known OEM quirks for HP and Lenovo laptops.
  • Immediately recharge the battery. Do not use the laptop if possible.

BIOS lockouts and known OEM quirks

  • (BIOS lockout) HP laptops have a 15% BIOS lockout and need to be bypassed for a full discharge. Immediately charge the battery once the laptop shuts off.
    • All HP laptops/2010+ Compaq.
  • (BIOS lockout) Some Lenovo laptops have a 7% critical capacity lockout (0190).
    • Only occurs if the laptop shuts off early. Easily bypassed.
  • (Known quirk) Some Dell batteries hold incorrect data once the battery is nearing the end of it’s life. This self corrects with time and a later recalibration. I have seen this on a Dell NX31D (2014/E6440) and a RMJFW(2014/E6220)

What you need

  1. Recalibrating laptop batteries, Log the original calibration data: step 1, image 1 of 1

    • This battery is too far gone for realibration.

    • Before recalibrating the battery, charge the battery to 100%. Take a note of the initial data.

  2. Recalibrating laptop batteries, Use your laptop: step 2, image 1 of 3 Recalibrating laptop batteries, Use your laptop: step 2, image 2 of 3 Recalibrating laptop batteries, Use your laptop: step 2, image 3 of 3

    • Any data from this step will be lost. Only plug the laptop in to get the machine started from a BIOS lockout.

    • Use your laptop while it is discharging. Do this until the computer shuts down.

  3. Recalibrating laptop batteries, Plug your laptop in: step 3, image 1 of 2 Recalibrating laptop batteries, Plug your laptop in: step 3, image 2 of 2

    • While it is safe to use your laptop, the calibration accuracy may be affected.

    • Every laptop has a different charge indicator. When your laptop is fully discharged, plug it in immediately. Fully charge the laptop.

  5. Recalibrating laptop batteries, Verify the new calibration data: step 4, image 1 of 1

    • This procedure may "kill" end of life batteries.

    • Once you are finished, check the BMS data. The reported data should be corrected.

  6. Recalibrating laptop batteries, (Windows 10) Battery health check: step 5, image 1 of 3 Recalibrating laptop batteries, (Windows 10) Battery health check: step 5, image 2 of 3 Recalibrating laptop batteries, (Windows 10) Battery health check: step 5, image 3 of 3

    • This may not work if your battery is older, even if it is OEM.

    • Run Command Prompt as an administrator. Enter powercfg /batteryreport.

    • When the report is ready, you will receive a message stating where it is located. Check the data for consistency.

  7. Recalibrating laptop batteries, (HP UEFI) 15% lockout bypass: step 6, image 1 of 3 Recalibrating laptop batteries, (HP UEFI) 15% lockout bypass: step 6, image 2 of 3 Recalibrating laptop batteries, (HP UEFI) 15% lockout bypass: step 6, image 3 of 3

    • This will fully discharge the battery. HP diagnostics do not charge of the battery.

    • Plug the laptop in and turn it on; unplug it once it is on. Press ESC and select System Diagnostics.

    • Open the Component tests submenu. Select Memory or Hard Drive.

    • Select Extensive test. Choose Loop until error.

    • When the laptop shuts off, immediately recharge the battery.

  8. Recalibrating laptop batteries, (HP Legacy BIOS) 15% lockout bypass: step 7, image 1 of 3 Recalibrating laptop batteries, (HP Legacy BIOS) 15% lockout bypass: step 7, image 2 of 3 Recalibrating laptop batteries, (HP Legacy BIOS) 15% lockout bypass: step 7, image 3 of 3

    • DO NOT apply these settings to your primary OS. They may damage the battery.

    • Boot the laptop into a live Linux Mint Cinnamon session. Open Settings and make the following changes:

    • Open Power Management. Change When the battery is critically low to Do nothing.

    • Use the laptop until it shuts down. Everything from this session will be lost.

  9. Recalibrating laptop batteries, (Lenovo 0190) critical low battery bypass: step 8, image 1 of 3 Recalibrating laptop batteries, (Lenovo 0190) critical low battery bypass: step 8, image 2 of 3 Recalibrating laptop batteries, (Lenovo 0190) critical low battery bypass: step 8, image 3 of 3

    • Plug the power adapter into your laptop. Allow POST to finish before unplugging the laptop.

    • Disconnect the laptop once the laptop is booted. Finish discharging the battery.

  10. Recalibrating laptop batteries, (Optional) Label the battery: step 9, image 1 of 2 Recalibrating laptop batteries, (Optional) Label the battery: step 9, image 2 of 2

    • To better track the estimated health of the battery, labeling is recommended.

    • Note the date of the recalibration.

    • Note the original charge capacity (Designed capacity).

    • Note the current capacity of the battery (Full charge capacity).

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