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Laptop Battery Not Charging To 100%?

Is your laptop battery not charging to 100%? Often times in new batteries the laptop
and operating system are unable to correctly measure the charge of the new battery.
Your battery likely has a 100% charge but the power gauge is giving you a false reading.
If your laptop battery is not charging to 100% you will need to calibrate your battery.

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How to Calibrate laptop battery with Microsoft Windows
Calibrating a laptop battery simply means resetting the battery gauge to display the level of charge accurately. You may notice that your laptop battery meter is inaccurate when you install a new battery or when it hasn't been for a long period of time. If the laptop percentage is stuck or inaccurate you need to calibrate your laptop battery. There are two methods to calibrate
Method 1: Calibrating the battery while PC is in use
Calibrating the battery requires a cycle of a complete charge and complete discharge. If the PC is being used during this calibration cycle, the power management properties must be disabled to allow the battery to completely discharge. To calibrate the battery with the computer on:
  1. Connect the AC adapter and fully charge your computer
  2. When the battery has charged to 100%, remove the power adapter from the computer. An overnight charge will charge your battery to 100%, even if the battery meter indicates you have less than a 100% charge.
  3. Click Start, click Control Panel, and go to Category View
  4. Click Power Options, click Performance and Maintenance, and go to Power Options .
  5. On the Power Schemes tab notice and record the default settings. You will need to reset these values later.
    Figure 1: Power Options Properties Window
  6. Select the Always On Power schemes value. Then select the Never value for all topics in the Running on batteries column.
    The Always On settings prevent your notebook from entering Sleep mode and allow the battery to drain faster.
  7. Click Apply to accept the values and force the battery to consistently discharge. The notebook is in constant operation during the test period.
  8. Allow the battery to discharge completely until the notebook PC turns off.
    The battery is now calibrated and the battery level reading on the power meter is now accurate.
  9. Plug in the AC adapter and restart your notebook.
  10. Return to the Power Options Properties dialog box (Step 5), and re-enter your power savings settings to the desired level.
Please note you will need to charge and partially discharge your battery before completely draining it otherwise you may kill your battery.
The maximum capacity of the battery will decrease with time and use. Eventually you will need to purchase another battery.
Method 2: Calibrating the battery while PC is not in use
Calibrating the battery requires complete charge and discharge cycle. To calibrate the battery while using the PC is not is use, complete the following steps.
The calibration may take 1-5 hours depending on the age of the battery and the configuration of the notebook PC you own. The PC should not be used while you perform the following steps. Completing all the following steps will also calibrate the battery so that the power meter readings are accurate.
  1. Shut down the notebook PC
  2. Connect the AC Adapter to the notebook PC and to an electrical socket.
  3. Charge the Notebook PC until the Battery Charge light is Green . This indicates the battery is completely charged.
  4. Press and release the Power Button to start the computer.
  5. Press the F8 key several times when the startup Logo or the laptop manufacture name displays.
  6. When the Windows Advanced Startup Menu displays, select the Startup in Safe Mode option.
  7. Remove the AC power adapter from the notebook PC.
  8. Allow the battery to discharge completely until the notebook PC turns off.
  9. The battery is now calibrated and the battery level reading on the power meter is now accurate.