This document pertains to HP Notebook PCs with Windows.
Resolving "Battery Not Detected" Problems
Sometimes Windows does not detect the presence of a battery. This can occur even if you have a good battery. There are several things you can do to resolve this problem. HP recommends doing each of the following steps, in order, and then testing to determine if the battery is detected after performing each step.
You can test for the battery while the AC power is connected and when the computer is running on battery-only power.
Performing a hard reset
Performing a hard reset erases all of the information that is stored in the temporary memory and forces Windows to do a complete scan of the system, including the battery.
To perform a hard reset, follow the steps below.
- Unplug the AC adapter from the notebook PC and remove the PC from any port replicator or docking station.
- Remove the battery from the notebook battery compartment.
- Press and hold down the power button for about 15 seconds to drain any residual electrical charge from the capacitors.
- Insert the battery and plug the AC adapter back into the notebook PC.
- Press the power button to turn on the notebook PC.
- Use the arrow keys to highlight Start Windows Normally , if it is not already highlighted, and then press the enter key.
Resetting the BIOS defaults
Resetting the defaults in the BIOS removes any possible incorrect values and returns the BIOS to a known good condition.
To reset the BIOS defaults, follow the steps below.
- Press the power button to turn on the notebook and repeatedly press f10 to enter the BIOS setup.
- Navigate through the BIOS and select the option to restore the BIOS defaults. The option will have words like Restore Defaults or Setup Defaults .
- Confirm that you want to restore the BIOS defaults, and then select the option to save and exit the BIOS setup.
Updating the BIOS
If resetting the BIOS default setting to the original condition does not resolve the problem, look for and install an updated BIOS.
For instructions on updating the BIOS, please see HP Notebook PCs - Updating HP Software, Drivers, and BIOS with HP Update Tools .
Use HP Battery Check to test the battery —if the battery is still not detected, please follow the steps in the Using System Recovery to re-install the operating system section of this document.
Determine if the notebook starts using battery only
Disconnect the AC power from the notebook PC and then try to boot the notebook PC on battery-only power.
- If the notebook PC boots on battery-only power, then re-install the operating system using System Recovery. For instructions on using System Recovery, please see HP Notebook PCs - Using HP Backup and Recovery Manager .
- If the notebook PC does not boot on battery-only power, then please contact HP for assistance.
Test the battery
HP provides the HP Battery Check utility to help you test the battery. Battery Check is part of the HP Support Assistant that is installed on HP computers shipped with Windows 7 or Vista, and is available for computers that were upgraded from XP to Vista. To get the latest version of the HP Battery Check, download and install HP Support Assistant for your model; or see HP Support Assistant (English only) .
To locate and use HP Battery Check using HP Support Assistant, follow the steps below.
- Click Start and select HP Support Assistant .
- On the HP Support Assistant window, select Troubleshoot , and then select Power, Thermal, and Mechanical .
- On the Power tab, click Battery Check to examine your battery and display the results of your battery status check.
The current state of the battery (charging or discharging) is displayed.
For more information about the Battery Check see HP Notebook PCs - HP Battery Check Frequently Asked Questions .