The surprising part of the HC30 is not stated Low Voltage Protection...but if I remember it starts stepping down (Not sure have not had time to work with mine yet)
Djozz - I think all of the manufacturers are going to go back to a AA/14500 offering. I know that one competing manufacturer has just made one and that another is considering so Nitecore hopefully will follow suit. They can still get 500-600+ lumens out of a 14500 nowadays.
BTW...these dogbone headlamps are relatively easy to mod...LED's and/or drivers
I bought it from FastTech, along with some 10, 25 and 45 degrees ones.
I’ve tested them in multiple lights and found that 45° is really useful indoor !
I don’t think you can physically get a 100 degree TIR, the specs are for HALF the angle of spread (ie a 20 degree optic will give you a 40 degree cone).
I switch the led for a warmer last year, change it for a XM-L2 4D. This is how it looked inside. Maybe you have fixed it by now. There is more pics if some one needs.