Battery lasts only 90 to 100 minutes, is this normal?

[Tausendberg]

https://www.vive.com/eu/accessory/xr-battery-cradle/

According to this, the battery lasts "up to 2 hours" but in my case, pcvr streaming 200 mbps Ultra graphics, I only get about 90 to 100 minutes.

My Focus 3 will go over 120 minutes every time. 

Is this normal behavior or do I have a bad battery?

[Tausendberg]

I just tested it with a stopwatch app, just to be really certain, 

and from the moment I turned on the xr elite and saw the white light go on in the front til I ran it down to 3%, it took exactly 92 minutes and 30 seconds. 

Do I need to make a warranty claim or is this normal? 

If it's normal then, I'm fine with using one of my external batteries, I just need to know what to expect.