Trying to push 30A through springs is a very, very difficult task.
Honestly, I have to say Nitecore was both lazy, greedy, and impatient in this regard.
Why? While they are right in regards that the springs would oxidize, they didn’t tell why…
Well, at 30A, any normal spring would melt pretty much instantly.
Here’s the thought process Nitecore probably had:
1. Let’s use gold plated steel springs. Oh no, they failed at 6A.
2. Let’s use gold plated dual steel springs. Oh no, they failed at 9A.
2. Let’s use dual phosphor bronze springs. Oh no again, they failed at 18A of continuous use.
4. Well, nothing on the market actually exists that can handle the load of a 100-120W light running off of a single cell.
Let’s put a 10A cell in a 30A flashlight and weld nickel plated copper strips instead.
If the engineers, or rather, Nitecore, actually put in effort into designing adequate contacts, they should’ve just looked at BLF and see what members cooked up in spring design.
They could’ve used dual gold plated BeCu C17500 springs, and they would’ve worked quite well if they had waited for a 25-30A cell.
Why do people always think conventional? You just need not the spring to conduct the current!
just use the spring to push the contact against the battery, you could use the same sort of contact like for spotwelding just with a bit raised button
Or use a springless contact. Like DQG.
In a constant-length light that doesn’t need daily cell swaps (like that Nitecore) one could use a contact screw.
BTW I haven’t seen that Lumintop contact. Looks like a professionally done spring bypass.
I have zero interest in this Cu/Ti E07 after being totally disappointed in the D4 Cu/Ti. The D4 gets blaz'n hot in a couple seconds - pretty useless unless you got thermal protective gloves to operate the thing with. Sure, copper is great for thermal transfer, but there's gotta be a better way to use it, like wrapped in aluminum maybe, I dunno....