I have a handful of nichia gs 5mm leds in my spare parts box so I trimmed one and popped in in an old minimag I had laying around. Drilled the reflector to fit but otherwise no mods. Put in some 2-3 year old store brand batteries and started a runtime test. From the get go not as bright as a nite ize conversion but pretty equal to my photon. We are now 90hrs in and subjectively I’d say it’s down to 50% of initial brightness. Very impressed so far! Definitely a great BOB or hurricane option.