If so, someone over at singletrack did a few sums and reckoned runtime would be about 40 minutes. Possibly a good candidate for a bit of homebrew 18650 battery pack shenanigans.
Just read the instructions you can set it to max or reduced power by partially holding in the on/off button time given on one set of batteries at max is 10hrs and at reduced running at 35-50% 14hrs.....only one way to find out.