Laptops use lithium-ion rechargeable battery cells. Depending on the amount of cells in the battery assembly, as of 2011, a laptop battery can last anywhere from four hours to 12 hours between charges. Laptop batteries have a finite amount of charge cycles before they no longer function. When that happens, it can either be a failure of one or more of the individual cells or a failure of the control circuitry in the battery assembly. However, your laptop battery doesn’t have to be dead for your computer to have difficulty detecting it. It could be a hardware issue, a software issue or even a poor connection

1 Check the settings in “Power Options” in the “Control Panel.” Open the “Control Panel” from the “Start” menu and double-click the “Power Options” icon. Check the settings in the “Running on batteries” section of the “Power Schemes” tab. If the “Turn off monitor,” “Turn off hard disks” and “System standby” settings are set to shut your computer down after only a minute or two, adjust them to a longer time limit. Click the “Power Meter” tab and check the “Show details for each dell laptop battery” box.

2 Update your drivers. If the “Power Meter” tab displays an “Unknown device” or “Battery not recognized” error, go to the website of your laptop’s manufacturer and update your drivers to the latest version. If your laptop drivers are all up-to-date, update your Windows processes. You can do this by clicking the “Windows Update” link in the “Start” menu. Device driver issues can often occur when updating an older laptop to the Windows 7 operating system.

3 Perform a hard battery boot. Shut down your laptop and disconnect the dell AC power cord and the battery. Wait 30 seconds, then put your battery back in and boot up your computer. This will reset the control circuitry in your xps l702x battery. If your computer doesn’t boot, it may be a physical problem with the battery.

4 Check the metal connections on the battery and motherboard. If there is any debris, tarnishing or residue on the battery connections, they will not work properly. Shut down your laptop and remove the AC power cord. Clean the dell xps l702x laptop battery terminals with a very-fine grit sandpaper. Blow away any dust, reconnect the battery and boot up your computer.

5 Replace the battery. If your laptop battery has simply reached the end of its life, the only option is to replace it. If you replace the battery and your computer still does not boot with only the battery attached, it is likely that the battery connection circuitry on your motherboard has failed.