Testing and Calibrating the Battery (Windows 7)
This document pertains to HP and Compaq Notebook PCs with Windows 7.
The maximum capacity of a battery changes over time. Because of this change in battery capacity, the charge level indicator in Windows might not show 100% charged. To know the condition of your battery, use the steps in this article to test your battery and calibrate it if necessary. Calibrating the battery resets the battery gauge to accurately display the charge level in Windows. In this article, two methods of testing and calibrating the battery are explained. Also, a manual method for calibrating the battery is presented.
Checking for the latest updates
The UEFI System Diagnostic is available on most HP notebook PCs, manufactured after late-2008. An updated BIOS and updated System Diagnostic may be available for your computer. If so, download and install the UEFI. Go to the Software Drivers and Downloads page for more information. Install the latest version of HP Support Assistant from the HP Support Assistant home site.
Testing and Calibrating the battery using HP System Diagnostics (preferred method)
To test the battery using the HP PC Diagnostics UEFI or the HP System Diagnostics , start with the computer off and unplugged from the power. Use the following instructions to test the battery:
- Unplug the power cord and turn off the computer.
- Press the power button to turn on the computer.
- Press the Esc key immediately when seeing the HP or the Compaq logo screen.The Start Up menu appears.
- Press F2 to select F2 System Diagnostics .
- Select Battery Test from the list of diagnostic or component tests.NOTE:If your battery is fully charged, the battery test screen might not appear.
- Plug in the power cord.
- Click Start Battery Test on the Battery Test page.The Battery Test page shows Test in progress and the Estimated Time Remaining.When the test completes, one of the messages and suggested actions from the following table displays:
Status Message Suggested action OK The battery is functioning properly The battery does not need calibration. Read the remainder of the message for more information. Calibrate The battery is functioning correctly, but it needs to be calibrated. Read and respond to the message that appears. If the option to use the HP battery auto calibration feature displays, this is preferred. Otherwise, click Learn How to Calibrate your Battery for the steps to calibrate your battery.NOTE:Battery calibration might take several hours to complete and is best performed during long periods when the computer is not in use. Weak
The battery is functioning correctly, but due to normal aging of the battery, the battery life between charges is now significantly shorter than when it was new. The battery should be replaced to get the most working time out of your battery. If your computer is within its warranty period, you can Contact HP (in English) to verify if your battery is covered under the warranty. Replace The battery is reporting a failure and needs to be replaced as soon as possible. Replace the battery. If your computer is within its warranty period, you can Contact HP (in English) to verify if your battery is covered. No Battery A battery is not detected. A battery is not installed or detected in the battery compartment. If a battery is installed, remove the battery and inspect the pins to see if there is dirt or other foreign matter blocking the connection. Fully insert a battery into the compartment if a battery was not inserted and you want to test the battery in that compartment. Unknown HP Battery Check was unable to access the battery. Remove and reinsert the battery. You might need to download and install all the updates from HP Support Assistant.
Testing and calibrating the battery using HP Support Assistant
HP Battery Check is a utility in HP Support Assistant that provides a simple but accurate test of the battery.
NOTE:Many issues with HP Support Assistant can be resolved by downloading and installing the latest version of HP Support Assistant from the HP Support Assistant home site (in English).
To use the HP Support Assistant to check and calibrate the battery, follow the instructions in this section:
- Click Start .
- Click All Programs .
- In the Programs list, click HP , and then click HP Support Assistant .
- A welcome screen appears if it has not been deactivated. Use this screen to set how HP Support Assistant handles updates, whether a taskbar icon or pop-ups are displayed, and to share anonymous usage data with HP. Remove the check next to Show this screen when I open HP Support Assistant to avoid seeing this window in the future.
- Click Next to go to the HP Support Assistant main page.
- To access the HP diagnostic tools using HP Support Assistant, click the My computer button from the main page.
- Click the Diagnostics tab, and then click the HP Battery Check box.The HP Battery Check begins.
- HP Battery Check displays the test results when the test is complete.Status results you might see are:
With each status result you see, there are on-screen instructions. Follow the instructions to calibrate or replace the battery as needed.
- Weak or Very Weak
- Failure with an ID number
- No Battery
Calibrating the battery manually
Manually calibrating the battery requires four steps: fully charge the battery, discharge or drain the battery, recharge the battery, and then run the battery test. This calibrates the battery so the battery gauge accurately displays the level of charge.
NOTE:When possible, use HP System Diagnostics (described above) to test the battery and get calibration instructions. The following instructions are for a manual method that works with most battery types.
Step 1: Charge the battery
- Plug in the power cord.
- Charge the battery to a full charge.
- When the battery is fully charged, proceed.
Step 2: Discharge the battery
- Disconnect the power cord.
- Shutdown the computer.
- Press the power button to start the computer.
- Press the Esc key when the HP or Compaq logo screen appears. You might have to try this more than once to see the Startup menu. If Windows opens, shut down the computer and start again.
- Press F2 to select F2 System Diagnostics in the Startup Menu .
- Click Hard Disk Test .
- Leave the computer on and allow the battery to fully discharge while doing the Hard Disk Test.NOTE:You are doing the Hard Disk Test only to drain or discharge the battery, not to get the results of the test. The battery discharges and the computer turns off before the test results display.
Step 3: Recharge the battery
- Plug in the power cord to charge the battery.
- Charge the battery to a full charge, 99%-100%.
- Check the battery charge. Turn on the computer and start Windows normally. Mouse over the battery icon in the system tray.NOTE:The battery continues to charge with the computer on or off.
- After reaching a full charge, keep the computer attached to the power cord for (at least) 2.5 hours.NOTE: If you plug in your power cord and immediately run the HP Battery Check, you might get a false failure showing the battery is bad. If the battery is in a low charge state (at less than 3%) you might also get a false reading.
Step 4: Run the battery test
- Ensure that the power cord is plugged in.
- Press the power button to start the computer.
- Press Esc on the keyboard when the HP or Compaq logo screen appears.
- Press F2 to select F2 System Diagnostics in the startup menu.
- Click Battery Test .
- Click Start Battery Test on the Battery Test page.The Battery Test page shows Test in progress and displays the Estimated Time Remaining.The results of the battery test display on the Battery Test page. If the battery is calibrated, the Battery Test reports PASSED .If the battery status is “Calibrate”, run the battery test again. If the battery does not calibrate a second time it might need to be replaced. Purchase a new battery by going to HP Batteries (in English).