Hi @azer, since you are running only windows, its easy to calibrate the battery. Follow the below steps.
In cmd ran as Administrator, type the following
powercfg -setdcvalueindex SCHEME_CURRENT SUB_BATTERY BATACTIONCRIT 0
Now go to Control Panel\Hardware and Sound\Power Options
Click on plan settings of your power plan. Make sure the critical battery action is selected as Do nothing.
Then discharge the tablet completely.Better do nothing when the battery reaches 1%. When battery dies,charge it for 8hrs without turning on.