with that monitor, the one i recommended should give you 70+ minutes run time, plus the battery should go 5 years useful life
cyberpower includes an interesting watt draw widget with available run time remaining, that gives a good "pulse" on the life of the battery - when you see run time dropping down to 15 or less minutes, you know it's time to replace the battery
here's a shot of the widget - i keep it active on the bottom right corner of my desktop -
https://imgur.com/a/HRHD2
the computer this widget is on is running a cyberpower CP1500PFCLCD UPS, the 1 hour 11 minute run time estimate basically reflects the computer is near idle except for web browsing. When i'm rendering a video and the cpu is at or near 100% usage or load, the estimated run time is 35-40 minutes
The UPS is also powering a 10 watt unmanaged switch and 4 security cameras (5 watts each) 24/7