My laptop is HP Pavilion au620tx and it is not charging over 13 and sometime 16 percent.
I tried updating microsoft ac adapter and microsoft ACPI. I reinstall both the drivers but nothing happens. So i tried calibrating the battery using F2 and it says AC adapter required to calibrate the battery. I am not able to understand what is the problem and battery is non-removable.
Help will be appreciated.
Battery should be removable you will just need to take the bottom of the case off to get to it. First thing to do here is replace the battery and see if that helps. Did you check the power options to make sure you did not set the battery to stop charging after that %? Power options offer custom settings like that to help with battery life.
Laptop batteries stop charging properly if you never use them. If you keep it (or any battery powered item for that matter) plugged in for power even after the battery is fully charged, eventually the battery will stop taking a charge and eventually the device itself will likely stop working. Get a new battery, charge it to full, unplug and use the thing with the battery alone. Once it drops its charge to about 10%, plug it in and charge it to full again.
Some devices have a trickle charge function that protects this from happening but it is generally a good idea to let the battery do its job and use the power cord to recharge rather than using it as an alternative to the battery.