My understanding is that by volume copper can hold approximately 60% more heat than aluminum. This means the copper takes longer to saturate with heat so in theory it might hold more before it overheats.
But on the other hand, copper also conducts heat far better than aluminum. This can be both good and bad when it comes to turbo modes.
It is good because the better heat conduction helps move heat away from the emitters and other electronics helping them to stay cool.
However, the temperature sensor that controls the thermal rampdown is located in the MCU on the driver board. A copper head may mean heat conducts from the shelf back to the driver board faster than an aluminum head. This could result in the light ramping down as fast or even faster than the aluminum version.
You can mostly override thermal rampdown with firmware settings. However, copper again shows a disadvantage. It conducts heat so well, instead of just the head of the light being too hot to touch, the body tube itself might become too hot to touch. The result is the limiting factor in turbo output changes from “protecting the electronics” to “protecting your hand”. It doesn’t necessarily help if the light is able to run on turbo without damaging the electronics, but you need an oven mitt to actually touch the light without burning yourself (and possibly risk the battery overheating and exploding).
Another thing: Copper conducts heat better and has more thermal capacity than aluminum. But you still need to get the heat out of the light. There are three mechanisms that makes this happen:
Emissivity - the hot metal emits the heat as infrared radiation. Shiny copper or aluminum has low emissivity (bad). Dark anodized aluminum and tarnished copper has high emissivity (good).
Convection - air circulating around the exposed pieces of metal takes away heat from the light.
Conduction - your hand absorbs some heat from the light.
I just noticed that there are different colors of LEDs available for the backlight on the switch. Does anybody have any pics? Would love to see the red…
Last time the site was suspended for others it worked for me on my phone but I also got the “Suspended” message when I tried a different Internet connection. It seems work fine on different connections now though…
dude… i couldn’t relate more! I just bought my first d4v2 in brass with osram w2… cost me $100. that was 3 weeks ago and now im probably buying the copper. and if Hank ever comes out with kr4 brass and copper i’m definitely buying one of those. And i am buying the k1 in green body. and i already have 5 emisar / noctigon lights. Hank is KILLING ME