Following my story I was asked in a private message questions about the lights I build so I thought it might be worth sharing here as well.
For some lights, I build the casing myself and for others I use casings of old caving lights. I am only using simple hand tools that most people have at home.
All lights are "cave proof" and were tested is caves all over the world.
Each light have Two Cree XM-L2 emitters and TIR optics so the maximum potential output is about 2400 lumen but I only enable 1000 lumen on turbo mode.
For the Spot beam I am using 10-15 degrees lens and for for the flood beam 90 degrees or even a bare LED.
The driver has 8 AMC7135 current regulators for each channel and it runs my own Firmware. The Firmware features are:
Low battery warning.
Low battery protection.
Battery check mode.
Automatic step down from bright modes to prevent over heating.
Automatic lock off to prevent accidental turn on in the bag.
3 uA leakage while off.
And more..
I believe all these features are really important for cavers but unfortunately not all brands offer these functions.
I have posted detailed instructions online on how to build these light and have an GitHub repository with all my firmware code so if you are interested, you can build yourself a caving light