Why do you want the Battery out of the laptop in the first place?... The laptop runs on the Battery not on the Charger, so you can't run it on the Adapter ONLY.
It's: Charger => Battery => Laptop
Not: Charger => XXXX => Laptop
The charger converts 110-125 AC volts to 19+ DC Volts and with those 19V it charges the battery up to 12 V or slightly higher, and on the voltage the laptop runs, not on 19+ volts.