A couiple of ideas -
- Since the TH20 also runs off of 14500. Lithium ION's are a couple of grams lighter than NiMH.
- If you want to stick with AA, the Manker E03H and Acebeam H40 both weigh a couple of grams less than the TH20.
- Otherwise, switching battery formats to a smaller AAA (the Manker E02H is nice) would be a change that could cut weight in half.
- I notice that Thrunite has a new 18350 model TH1 which is also a couple of grams less.
FWIW, one thing I've noticed is the difference balanced weighting makes. I've used headlamps with a separate battery pack (on back of headband) that "feel" less heavy because the batteries in back offset the lamp weight in front.