I was experiencing this problem first hand, so I know what a pain it can be. At first the laptop would shut down when the battery indicator dropped to 20%. After a while it became 25%, then 30%, 40% - it was getting worse!
I just couldn’t tell when the laptop would shut down on battery power and it could happen at anything below 50%. The hours and minutes left was also way out. When I thought I had an hour or more left, it would shut down. Usually at the most inconvenient moment.
Laptop battery calibration
When the battery meter in the taskbar becomes this bad, you need to calibrate the battery. What this means is setting the meter to show the maximum charge as 100% and the minimum as 0%. If the laptop shuts down at 25%, we need to reset the meter to reflect that it has only 5% charge and not 25%.
Battery calibration does not affect how long the laptop lasts on a charge or how much charge a battery can hold, which degrades over time anyway.
All it does is make the display of the charge level and time remaining more accurate. Knowing that there is only half an hour left enables you to finish your work, find the charger or send the email you have been meaning to send, but not got around to.
There are several ways to calibrate the battery in a laptop and you might need to try more than one to fix the battery meter display so that it is accurate.
Plug in the battery charger and fully charge the laptop. It needs to be at 100%.
Open the Control Panel and open Power Options. On the left, click Create a power plan. Select the plan that is closest to what you want to use. Name your plan and click Next.
Set the display to never turn off and the computer never to sleep when running on the battery
Make sure the plan is selected and then just use the computer as normal until the battery expires and the laptop shuts down. Plug the power cable in and power up the computer.
The battery should now be calibrated. You don’t need to stick with the power plan you created and others can be selected as and when needed.
Check the battery in an HP laptop
Some computers have built in diagnostics that can be used to check the hardware components. For example, turn on an HP laptop or notebook computer and press the F2 key several times.
Instead of starting Windows, the HP PC Hardware Diagnostics UEFI utility appears. Use the up and down arrow keys to highlight Component Tests and press Enter to select it.
A component menu is displayed. Use up/down arrow keys to select Battery and press Enter.
Select Run once and press enter. A quick battery check is carried out and it says it takes two minutes, but it was more like 30 seconds on my computer.
If a problem with the battery is found, then the Battery Calibration test is performed. This could take up to four hours, so don’t run this test if you urgently need to use the computer to get some work done.
Afterwards, return to the main menu and quit to boot up to Windows as normal.
Reset the battery
Different computers use different methods to reset the battery or calibrate it. Another quick fix is to power off the laptop and then hold down the power button for 10 to 15 seconds.
If you have an old Lenovo laptop, plug in the power adapter and charge it up. Then go to Power Manager > Battery tab > Battery Maintenance. Click the Perform Reset button.
With a newer Lenovo laptop, run Energy Management and click the gear icon. Click the Start button next to Battery Gauge Reset. You need to connect to the mains power and close all applications before clicking the Continue button. It takes several hours to run, so be patient.
Another way to reset a laptop battery is to charge it to 100% and then run it until it shuts down. Repeat this three or four times.
Replace the driver with Device Manager
There is one more fix for battery calibration and I covered it in Dig deep into Windows power settings to extend laptop battery life.
There are lots of battery tips there, but briefly, open Device Manager, expand Batteries, right click Microsoft ACPI- and select Uninstall.
There are many more tips in that article and it is worth a read.