A little bit more about real tests. The traditional expedition of the speleo club Perovo in the area of the Arabica massif(Abkhazia) to the Verevkina cave has just ended. Verevkina cave is the deepest(2212 meters.) cave of the world for almost a year.
In this expedition I used Panda 3 as the main light on the helmet. Just before expedition I replaced stock xpg3 by 351D 4000K 90cri it makes light much more pleasant, and much wider.
My task in this expedition was the topography of the so-called bottom labyrinth - an extensive network of subhorizontal courses beginning at a depth of 2100 m.
The path to this depth takes 3-4 days for 10-12 running hours ( with a load of ~ 30kg) along the vertical part of the cave. Characteristic forms of relief are vertical pit (up to 150 m deep with and without waterfalls) and short meanders between them of different widths.
Work on the rope takes most of ascend\descend time
Stops for overnight taces place in underground camps at depth 600m, 1300m, 2100m.
The most interesting part of cave starts at 2100m, where the modern cave, apparently, cuts a branched network of ancient siphon pipes. Now the known length is approx. 7-8km. This part consists of "pipes" with diameters of up to 16 m, siphons, half-siphons, halls, small vertical pit.
Work in the cave lasted 14 days, 7 for way down and up and 7 for topography.
Now about the flashlight.
The first question was fixing of the headlamp on the helmet. The rubberized strap was well held and did not slip over the plastic helmets.
This, along with the standard rubber band is enough for fastening, for 2 weeks did not fall down at all.
After 2 week in undergroung the only headlamp damage is scratches on anodisation.
Buttons are too small , sometimes it is hard to find them into gloves.
PWM at 15kHz is almost invisible, it can be seen on falling water..
Ipx8 is fine. Panda3 holds pressure drop ,100% humidity, dripping water.
The second mode of the flood light was enough for comfortable work with a rope at ascend\descend.
Quick access to the maximum mode of spot allows to view the rope far away. Vertical pit with depth about 40-50m can be enlighted by spot light.
During ascend(descend) I used only one 18650.
Situation in the topography of the bottom parts, was different. One need to inspect everything for good topography. The sizes of the pipes are different, according to this, the modes of headlamp were often switched. I mostly uses 2nd and 3rd modes in all possible combinations, and the maximum of spot.
(Siphon pipe. Depth is 2150m from the entrance)
In this case I change 18650 every day. In total I spend 8x 18650 for expedition (new GA).
I very like this headlam, during 99% of the time I did not recall about its existence)