So, overclocked, I had 130 minutes of power. And at the default speed I had 170 minutes. I’m considering trying an underclocked speed too, I guess 1.0 Ghz? Let me know, and I can use the same setup.
Here’s a chart for both overclocked (2.0) and default (1.5). I’m not sure why there is a faster dropoff at the start for the default speed. The only difference in my test was I turned the volume down immediately for the default, and I waited 5-10min for the overclock because I didn’t realize how annoying it was going to be. 
Otherwise, the task should have been the same.
And here’s the data. I converted the timestamps to minutes, for graphing purposes.
speed,voltage,battery,current,time
2.0GHz,4222000,100,3000,0
2.0GHz,3942000,98,1956000,5
2.0GHz,3920000,96,1970000,10
2.0GHz,3908000,95,1973000,15
2.0GHz,3902000,94,1990000,20
2.0GHz,3898000,93,1968000,25
2.0GHz,3886000,93,2004000,30
2.0GHz,3880000,92,1984000,35
2.0GHz,3867000,90,2006000,40
2.0GHz,3850000,89,2016000,45
2.0GHz,3830000,86,2034000,50
2.0GHz,3804000,84,2070000,55
2.0GHz,3780000,80,2052000,60
2.0GHz,3756000,77,2080000,65
2.0GHz,3733000,73,2096000,70
2.0GHz,3714000,70,2097000,75
2.0GHz,3694000,67,2112000,80
2.0GHz,3678000,64,2133000,85
2.0GHz,3661000,62,2103000,90
2.0GHz,3643000,58,2161000,95
2.0GHz,3623000,54,2151000,100
2.0GHz,3604000,50,2162000,105
2.0GHz,3582000,46,2180000,110
2.0GHz,3559000,39,2176000,115
2.0GHz,3536000,33,2213000,120
2.0GHz,3513000,27,2183000,125
2.0GHz,3488000,20,2210000,130
1.5GHz,4218000,100,8000,0
1.5GHz,3978000,92,1584000,5
1.5GHz,3955000,89,1651000,10
1.5GHz,3939000,88,1696000,15
1.5GHz,3932000,87,1697000,20
1.5GHz,3925000,86,1680000,25
1.5GHz,3919000,86,1702000,30
1.5GHz,3912000,85,1713000,35
1.5GHz,3906000,84,1712000,40
1.5GHz,3897000,83,1716000,45
1.5GHz,3885000,81,1712000,50
1.5GHz,3866000,79,1718000,55
1.5GHz,3845000,75,1747000,60
1.5GHz,3828000,72,1746000,65
1.5GHz,3806000,69,1750000,70
1.5GHz,3785000,65,1762000,75
1.5GHz,3765000,62,1777000,80
1.5GHz,3747000,58,1793000,85
1.5GHz,3727000,54,1824000,90
1.5GHz,3712000,51,1814000,95
1.5GHz,3697000,48,1799000,100
1.5GHz,3681000,45,1829000,105
1.5GHz,3667000,40,1824000,110
1.5GHz,3648000,35,1844000,115
1.5GHz,3633000,30,1826000,120
1.5GHz,3614000,25,1846000,125
1.5GHz,3593000,20,1875000,130
1.5GHz,3572000,16,1874000,135
1.5GHz,3554000,14,1890000,140
1.5GHz,3535000,12,1892000,145
1.5GHz,3512000,8,1904000,150
1.5GHz,3492000,6,1924000,155
1.5GHz,3474000,5,1943000,160
1.5GHz,3458000,4,1920000,165
1.5GHz,3439000,3,1954000,170
I might still try these settings I linked to, especially since it sounds like it worked, and they were able to still run web browsers with youtube, etc. So their device was still usable. Hmm.
