Battery life on enormous laptops like this is all but meaningless but, for the record, using the PC Mark 8 Home battery test this laptop lasted two hours and ten minutes. You might be able to squeeze closer to three hours out of it if you drop the screen brightness down and turn off any extraneous apps, but largely that’s your lot.
Meanwhile, if you’re considering gaming on battery power, you’ll struggle to get an hour. All of which is typical of machines like this.