This could have a 3 or 6 cell battery so the results vary because of that.

Also, usage can alter the result by about a factor of 10. shows
with the 6 cell battery (which new!) had a range from 1 hour 12 minute to 5 hours and 25 minutes.

That's about a factor of 5.

So if that's a 3 cell battery you might see a range of half that.