shouldn't the current be lower when the bulb is operating at a higher efficiency (voltage)???

if this chart (http://www.myra-simon.com/bike/lights.html#overvolting) is correct, the power req'd should be about 25w... which would result in 1.74A. So 2 hrs seems well within reach. I am a little concerned with overvolting 20% without any voltage regulation though... although i've read conflicting opinions on whether the soft starting will actually lengthen bulb life significantly. i guess we'll find out!