Hey,
Thanks for the input. Unfortunately 18350 will be a requirement as i’m building this torch to re-use my existing set of 18350’s. To be fair i’m not sure what to expect with 18350’s in terms of runtime. I guess 2 hours may be extremely unreasonable for any significant amount of brightness.
Ultimately because my limitation is an 18350 i will understand if this limits my top end for runtime. Interesting what you said about higher voltage causing higher heat. I’m not sure of the exact maths.
In this thread the guy is running stacked 18350’s he notes that running a single 18650 would yield better run time. Which confirms what you say.
However i’d be more interesting for the same amount of lumens. i.e. an XM with stacked batteries running slightly higher to match the lumens as XHP running slightly lower to achieve the same lumens. I’ve read that with stacked batteries i won’t have to worry about voltage drop which means the batteries aren’t stressed as much. I might end up building both to test.