Ultra lied brightly, but unfortunately in the description

Handling / General:
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Handling the lamp I find very pleasant. It weighs 307g incl. Batteries. It can be very easily attached to the helmet. By easily adjustable belts it also keeps very well.
The pressure switch is mounted on top of the LEDs and thus easily läst find and use.
The batteries are in the battery compartment, which is at the rear end of the bands. The battery compartment is closed by a rubber membrane stable. This serves as a rubber coating around the lamp a better grip on the head / helmet to offer.
The LEDs are slightly warm after prolonged use. But they are still easily touchable. The battery compartment (rear) mounted a red indicator LED. This dieht additionally as tail light. Although it is not very bright, but a nice idea.

Luminosity / coverage:
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Compared with the light of my Fiat Punto with low beam headlamp is bright and I thought that was really impressive. The single LED in the middle is fokusierend and provides a more point-shaped beam. Both LEDs have a broad set outer reflector. Since you can operate the LEDs in various combinations, and the illumination is adjustable.
More Details measured below.

Mounting:
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I use the lamp to go in the winter evenings after work ride with my horse. If I am then the evening with us in the winter after 18 o'clock in the forest and ride it's really dark. Therefore, I needed a headlamp, which can be mounted on a helmet and also so light illuminates, that my horse still looks as good in canter, that he shall not enter into any potholes. And that meets the lamp with flying colors!
Through the rubber coating of the headlamp it still holds even with larger movement very well on the helmet.
Only through the (relatively) far above housing the LEDs, the lamp is a little bit top-heavy. Took me but not really been disturbed. I also have my way in light rain and I can not see any problems with the lamp.

Battery life:
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The (main) battery life with the included batteries at full power for 45 minutes. After the 45 minutes, the lamp will slow a bit darker, but they can continue to use. And even after 6 hours it lights still (But then no longer brighter than a flashlight app on mobile ;-)). For a longer duration, I have worried me more batteries. These also have the advantage that they last longer.

Upload:
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For me only one adapter on USB came with. This fits into any standard USB port of computer or power adapter. In order to load works as expected good. Only a suitable power supply is missing. But although most of people have indeed inzwischenzeit to satisfy in the drawer.
On the side of the headlamp is a small round plug on the adapter cable. I'm not sure whether the Ladelektronik is in the USB cable or in the headlamp. Beautiful it would have been if a USB jack would have been on the headlamp, then you would not have the problem of lost special USB adapter cable.
But I think for me, the problem is more likely to keep within limits, because I'm just going home invite my spare battery with an external charger, and then replace the battery always box. So that is charged via these adapters obsolete.

So and now to the discrepancy between description and reality:

Battery:
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The easiest way to check the batteries were. Just start in a LiPo battery charger (in this case a Foxnovo F-4S) and capacitance measurement. In this case, unfortunately it turned out everything that the battery has only 1200mAh instead of 2000mAh specified.
Protected / not protected? That is the question. The batteries are indeed labeled as protected, but after I had the flashlight turned on one night was the battery voltage only 2.4V which is actually below the expected voltage shutdown. I have here the experiment terminated, to avoid damaging the battery.
I have therefore in the batteries a little looking around and tried and have become able to find the following batteries:

These are "only" given as 2500mAh, but they also deliver these.

LEDs:
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My first attempt to determine the brightness of the LEDs in the lamp I made a light meter and somehow I did not come to the expected values. As I
Then I chose a different (purely mathematical) approach. The headlamp was 45 minutes full power at 2 * 1200mAh battery capacity. This results in a power consumption of 3.2A gesammt. What at 3.7V power of 11.84 watts of power. Here no losses in the electronics are still counting.
If now the promise of 5000Lumen [lm] stipulates a 422 would be the lumens / watt. Mir is no LED on the market known who would do that. Even good (purchasable) LEDs have currently only about 110 lumens / watt. And even the laboratory prototypes in Cree also only 303 lumens / watt. This also explains why I did not come with my measurements to the expected values.

Luminosity measurements:
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To realisitsch compare the luminosity with other lamps I've been thinking it's probably easiest at 1m distance (distance between the LED) to measure the luminous flux and the light out area (diameter). I have to firstly used a calibrated light meter. But I have also measured with an Android app "Lux Meter" and am on comparable values ​​(The uncalibrated app shows about 10% -15% more). It can be seen 2 concentric circles illuminated. The inside is always the lighter in addition you can still see a darker outer ring.
The interesting for me lamps are equipped with circular reflectors. The lamps produce all a (relatively) narrow cone of light. By specifying the resulting cone of light (measured as diameter) and the measured light intensity in the lamps can then be quite easily compare with each other.
As all previously measured lamps aufwiessen maximum of 2 concentric rings of different brightness I have these designated by the inside and outside and this documented with its measured diameter and lux value. The measured outside the outer circle of light was always far less than 10% of other measured values. However, since from experience the measurement inaccuracies were 10% more likely in the area I have neglected this.
I am concerned at the light evaluation is not a 100% measurement. In my experience, the reality and the manufacturer's instructions for flashlights differ so far apart that it is more of an order of magnitude, and not to individual percent.

So here the readings:

In stage 1 (Only middle LED):
Interior 17cm with 7000 lux, 800 lux outside 120cm

Level 2 (the 2 outer LEDs):
Interior 30cm with 4200Lux, outside 80cm

Level 3 (all 3 LEDs):
Interior 15cm with 9000 lux outside, 120cm