A friend of mine showed me the Wurkkos HD20, so I immediately ordered the HD15, as the smaller version with 18650 sounded more fit. Seemed like the exact thing to have around the house or when travelling and seeing the many positive reviews, I quickly ordered one. So here are my thoughts on it.
The good parts of the light are pretty obvious and I will not spend much time about it. Here is what I think makes it great:
It’s bright, but can be dim and last a loong time.
Good color rendering index makes stuff look natural.
Charges from USB-C
Good-ish battery life.
The user interface is horrible
How hard can it be, it’s a button. Yes, a button that controls the flashlight towards one of 26 modes: you have 3 possible light sources (either one or both LEDs) that can operate in 5 continuous light levels and 3 blink levels, so 24 modes of light. Then you have the lock function and the check battery function.
Again, i repeat: there are 26 functions, all accessible through 1 button. It takes a bit of effort to learn it and it’s guaranteed you will forget after some times when you don’t use it. Access from one state to another also takes time, as you might need to apply different commands and wait for it to change iteratively from one to the next.
I asked my girlfriend to try and figure it out and after 5 minutes of erratic clicks she still could not find all the functions or understand how to consistently change settings. Good luck getting your grandma to understand how to use it. Flashlights should not be this difficult to use.
Poor thermal regulation
It has Advanced Temperature Regulation (ATR), which seems to work (poorly) in boost mode and not at all in high mode. Turn it on on high, leave it still for a few minutes and then it is burning hot when I wanted to grab it: 53.8°C on the body and 63°C on the head. This 53°C will burn your skin. Here is a thermal image:
Realistically speaking, the battery can handle it, the LEDs might be able to take it, but the flashlight is too small to dissipate as much power as it is trying to dissipate in High mode.
It lasts 2-3 times less than claimed
It’s unregulated, which means that as the battery gets lower, the light gets dimmer. The manufacturer uses this to their advantage and counts battery life until it goes to 10% of the initial level. But if I buy a light that is supposed to produce 400 lumens, I am not happy with 40. So i did my own measurements and counted the time until the light goes to 70% of the initial values. Here are my results:
-High wide – 1h 14 minutes – 2 times less than advertised
-High narrow – 1h 29 minutes – 2.7 times less than advertised
-High both – 54 minutes – 2 times less than advertised
-Medium both – 3 h 15 minutes – 2.2 times less than advertised
-Medium wide – 5h 05 minutes – 2.5 times less than advertised
-Medium narrow – 5h 40 minutes – 2.3 times less than advertised.
By all means, the real durations are quite good, it’s just that the manufacturer measures in a way that I consider sneaky and unusable which makes the durations overestimated 2-3 times. This review has charts where you can see similar data.
Too few light steps
Yes, after complaining that it is difficult to use because it has a lot of functions, my next complaint is that there are too few light levels. The lowest level, moonlight lasts about 100 times more than high (disregarding the turbo for now), but it is only 3 steps away. My other headlamps have a continuous variation of light intensity when I press and hold the button, which allows for a better control to reach right to the desired level.
In practice, I often find the High mode too bright and the Medium as not bright enough.
Update may 2023: now i can confirm that the light self discharges in about 3 months. This is really bad, because it will cause the light to be unavailable if unused for a long time.
Here are a few things that are rather neutral from my perspective:
The 1 m drop resistance for a headlamp seems insufficient, to 2m drop resistance would be better.
It pulls a lot of current when charging, has no regard for what type of charger you connect it to, it will pull 2.2A. If the port can’t handle it… tough luck.
I tried running with it, it’s not that heavy for not so fast running. Probably helped by the third headband. Still, i would recommend something else for running.
How it could be better
- A few more buttons to divide the functions. Four would be best: one for power on/off, one to change which LED is on, one to make it brighter, one to make it dimmer. This would be very intuitive.
- Proper thermal regulation. The handle should never reach more than 40C, independent on how it is used or external conditions, otherwise the metal body can burn the skin.
- Make it regulated so it keeps the same intensity for a long time.
- Better heat dissipation: make it out of plastic, except a bigger part of the head which is aluminum for heat dissipation.
- Turbo mode is on for a fixed 30 seconds, then drops to high and stays there. No more thermal cycling.