I plan to order an Efest 10440 (3.7V) battery for one of my BLF-348 lights. However, the Nichia 219 emitter appear to be rated for a maximum voltage of 3.3V.
The great review by mhanlen in this thread suggests it’s OK to run the BLF-348 on 3.7V, aside from some flickering when the light dims to protect itself from overheating. For those of you who own previous batches, is that also your experience with 10440 batteries?
If so, this makes me wonder whether I can run another Nichia 219 light (my Lumintop IYP365, with a tube designed for two AAA batteries) on one 3.7V 10440 and a spacer…