The LT1 can run on four, three, two or even a single 18650 cell on all modes. ( though as expected running on lest cells will shorten the run times consecutively in all output settings. (roughly based on subtracting 25% for each cell also minus about 5% when on a single cell. - DBSARlightAny good options that run on a single or at most two 18650s? I realize the Sofirn BLF LT1 can run on less but if I recall the manual states it doesn't recommend it cause of voltage issues.