Yes, driving the single spot at 38A, but reducing after some seconds then to ~32A.

I implemented this reducing mechanism for all channels: The very high power is reduced slowly to a level that is safe to operate.

Further, power is reduced if battery voltage drops too low and also with temperature rising.

But due to the 3kg heavy-metal, it can take multiple 100W, or even >1kW rather long.....

And main reason to build it: The building/design itself. Wanted to see what ist possible.

But I certainly also use it: I go out with the dog in the dark (no longer dark now ), and sometimes do some Jogging/Running in the dark.

Yes, there is a ATxmega128A4U MCU controlling everything (polling buttons, LED converter, charge converter, balancing, display, temp-sensors, ....).

I will do some more measurements (Candela) in the next days, but until now it seemed to be that at least for short time operation brightness reaches max at 38A (~560.000 cd for the center sport; ~520cd coming from the four SBT90.2 behind the 30mm TIRs).

Batteries are arranged 4s3p, resulting in 16.4V full voltage and 4+4+2.6 Ah capacity (measured around 150Wh energy; implemented and automatic battery calibration cycle, so that display now shows items like "runtime left").

There are always two 40T and one VTC5A in parallel, and then these four blocks are in series. So each parallel block is balanced as one cell. I had to choose this battery combination to have enough space available for the electronics. Initially I wanted to use 4x 40T in parallel with 70C LiPo, but due to savety and expected life span I went for save cells only. The pack is now capable of doing around 1.5kW for several seconds, and it does around 1.8kW in Flash Combat Mode. Plenty of runtime with 150Wh....

@Photon Master: interesting cells, good amount of energy per volume. But already now the battery pack delivers enough power to very quickly heat up both the lamp head (>1 kW being dissipated here on ALL_FULL button), and also the DC/DC converter (LED driver) section. Although efficiency being at ~93%, that still means ~100W peak power being dissipated on the driver PCB.

I checked that my chosen principle of conducting the heat originating from the MOSFET, the power-diode (boost converter) and the Induktors to the backside of the PCB, and then to the aluminium of the lamp body. Put a dense array of vias underneath the components, being filled with tin this conducts pretty good (PCB is only 0.8mm thick). Not suited for automated assembly, but for manual work good.

Originally I hab planned to go for 4x LiPo in parallel with 4x 40T, but for safety and reliability reason I then changed to save cells only. The LiPo initially chosen would have offered endless power: 357A continues, 714A short term current, meaning ~ 5000W continues power 

https://www.stefansliposhop.de/akkus/sls-speed/sls-speed-limited-edition-5100mah-4s-14-8v-70-140c::1927.html

But I made some bad experience using LiPo, lost a big lamp ~10 years ago due to LiPo cell fault:

https://www.candlepowerforums.com/vb/showthread.php?221261-Handheld-500W-LED-Power-finally-finished-(Beamshots-added)

@vit55: "Bleah, THOR mjolnir"....what does that mean? Interesting that you mention Mjölnir, that is exactly the name I chose for my device. Will engrave that later into the metal on several locations. I thought of this name because especially the tactical flash-combat mode is very impressive: Use currently around 1800W total power for flashing (2000W  would be possible, can be unleashed later per SW update), not measure yet, but should be >120.000 Lumen during flashes. So the name "Mjölnir" came into my mind....

Will do some beamshots and/or video clip one weather conditions here are better, currently we have continues rain....

@Th558: Thanks for asking this, did some measurements: You were right, the sweet spot for short term (some seconds) seems to be at ~34A; Changes SW now to begin at 34A, then drop down to ~30A over some seconds. I just implemented the 38A hardware-wise, to have enough headroom to max out the sweet spot per SW.

@CNCman: Thanks for the welcome words. Yes, several 100€ accumulated for material, beginning with the SBT90.2 being rather expensive. But that is ok, I will not build such a big one every year....took me already many hours of development and building time...

Thanks for the nice words

Maybe some words regarding usefulness:

When I began this project I set me as design targets:

• I want to build a LED light with > 1000W power, but still being in somewhat "normal" (big)flashlight factor
• I want to build a useful light, not only aiming at the "wow" factor when using it the first times

Form my previous builds I knew how useful a pure floodlight component is, especially when walking of running in the woods. You can move around the lamp a bit without loosing good sight on the items just in front of you.

My smaller builds had pure flood LEDs without any optics, and then a single spot, being as tight as possible for the chosen lamp size.

Using this combination, I was already very satisfied with flexibility I could achieve.

But I sometime missed something between the tight spot and the pure flood, to light up the path 10-20m in fron of you.

Now, looking at the spot: I made some experiments and fun builds aiming at very tight and intense spots. But although being very impressive and fun to play around with (light sword...), it is not really useful to light up only such a small spot at a far target.

For many of the "light sword" lights you must use binoculars in parallel with the light to make use of it. This becomes even more critical when moving (running or walking), because then the tight light ray bounces a lot and it is even harder to see something in the distance.

With this background I decided that for my big lamp I want the following:

• Lamp head should not be bigger that ~10x10cm (actually it is 10.4 X 11.4 cm)
• Array of big LEDs without optics for pure flood -> 8x XP70.2 
• Something between flood and spot, for 10-20m range -> 8x XHP50.2 in 20mm reflectors
• Spot in the range 4....8 degree FWHM, fitting in the head, and leaving space for the mid-range elements
  • 1x SBT90.2 in 62mm TIR (LLC56N) giving ~6° FWHM and ~600kCd
  • best space usage made me add 4x SBT90.2 in 30mm TIR (LLC05N7) with ~12° FWHM and additional 500kCd; very nice to light up not only a small spot in the distance, but instead significant area

This setup resulted for me in very good flexibility, offering useful, tight spot, and impressive amount of flood and mid-range lighting.

But at this point, let me put this question here in the community:

Do some of you really have use-cases for the super-long throwers, as they are also being offered these day a commercial products like for example Astrolux MF05 or similar?

I agree, as said above, very fun to play around with, but for real world usage not that often matching an opportunity.

As I just wrote about potential of battery:

This happens when one capacitor accidentally got mechanically damaged, then failing after some days:

Nearly finished repairing this, but the effect would have been significant worse if I had the 700A peak capable LiPo had in the design.....