finally got around to putting a cree Q5 in one of these lanterns. It measures 440ma on high and about 80ma on low. I proceeded to swap out the R5 resistor for a ~70 ohm resistor and now off of used duracell alkalines at 5.85v (4 batteries) it draws about 250-260ma on high and 28ma on low so runtime on high should nearly double with on low it should be triple. I am finding that using the solder wick trick to bridge the cree emitter contacts to the circuit board is the easiest for me to do. I was considering using a lower low but decided that about 80 hours runtime on low at the light level should be just fine and I estimate perhaps 8-10 hours on high from 4-6 (at 440ma).