Nebo 12K

The Nebo 12K has a rather unusual type of light source. Unlike 99% of flashlights on the market, it’s using a COB (chip on board), and is enormous compared to a ‘normal’ LED.

It sits behind a huge (plano) convex lens, which is not protected. Meaning, that the convex lens is exposed and can be damaged. And most zoomable flashlight use this same setup. But adding a glass lens for protection in front can be great. It’s much easier to replace a standard protection lens than finding the right convex lens, with the right size and angle.

The bezel has no glue and can be removed by hand. No need to have any special tools. This will give you access to the convex lens, which is held in place by the bezel and a thick o-ring. Once removed, you get access to the COB LED. An easily removable retaining ring keeps the light source in position. You’d have to unsolder the wires to remove the light source as a whole. Haven’t done that.

LED measurements

I set the light to high mode and used the widest beam. I then measured the center of the beam at a distance of about 70-80centimeters. I used the Opple Light Master 3 for this, which gave me the following readings:

• Light temperatures in CCT: 6207K
• Ra (CRI): 68.9

The beam temperature is what we call Cool white, with a low color rendering index.

I tested it again, but now zoomed in (tightest beam), and got the following:

• Light temperatures in CCT: 6106K
• Ra (CRI): 68.7

You can see that both measurements were very close in terms of CCT and CRI.

The beam is just a wall of light, without a prominent hot spot. And although pretty cool white, it’s not that bad in person, unless you want to observe plants from up close.

In the images below, you can see that Turbo has no PWM/flicker, but High mode has (although not visible by eye), and Low also has (also not visible, because it looks that it’s each row of LEDs in the COB that turn on/off.

• Length: 280 mm / 11 ”
• Length zoomed: 296 mm / 11.654″
• Head diameter widest: 63.9 mm / 2.51 ”
• Tailcap diameter widest: 36.5 mm / 1.438 ”

Weight: 

• Empty: 601.2 g / 21.21 oz
• With batterypack: 797 g / 28.12 oz

Long flashlights comparison

Size compared to other Nebo flashlights: Nebo Galileo 1000, Nebo Slyde King 2K, Nebo 12K, Nebo Luxtreme SL100

Next compared to other flashlights, from left to right: Nebo 12K, Maxtoch L2K, Maglite 3D, Astrolux FT03.

All 4 Nebo lights I’m currently testing use unique user interfaces. None is the same, which is quite interesting.

Available modes: 4

• Turbo,High, Medium, Low
• Main menu cycle: High, Medium, Low, Off..(Off is part of the menu, which is rather strange)

From OFF:

• Single-click: High
• Double click: Strobe
• Triple-click: nothing
• Press and hold: Low

From ON:

• If starting from High single-click <8sec: cycle to Medium – Low – Off
• If starting from Low single-click: <8sec: cycle to Medium – High – Off
• (If you wait longer than 8 seconds, a click will turn the light off (also strange)
• Double click: Strobe
• Triple-click: nothing, will just turn the light off
• Press and hold: ramps up to Turbo

Shortcuts:

• To Turbo: long-press from any mode.. not accessible from Off
• To Low: Long-press from Off
• To Strobe: double-click from On and Off

Mode memory:

• No, but you can get instant access to Low, High and Strobe

Blinky modes menu:

• Yes, strobe. Accessible with a double click

Low battery warning:

• Not really

Lock-out mode:

• No

PWM:

• Not very visible, but there is, according to the Opple Light Master data. Nothing to really worry about.

Firmware / UI Conclusion:

It’s unusual that you have OFF as part of the menu. Click High, click Med, click Low, click Off..
That’s weird for a flashaholic like myself. Also, when the light is on for more than 8 seconds, the next click will be off, instead of the next mode. That’s a little unpredictable when you are used to other UIs.

Fortunately, Turbo is still accessible after 8 seconds with a long-press

I’d rather have a long press for Off than Off being part of the menu.

The 12K doesn’t come with a normal battery, but rather a dual-26650 lithium-ion battery, with a capacity of 5,000mAh each, and because they are connected in series, have a Voltage of up to 8.4V (while maintaining a total capacity of 5000mAh). They fit snug, and there’s no rattling.

Note:

The battery pack looks special (and it probably is a little more than just 2 batteries connected) you can replace it with 2*26650 batteries, as long as they are button tops. I tried, and it works. They even charged with the built-in charging system.

But it’s not recommended because it could possibly void your warranty.

After charging the battery inside the light, I measured it at 8.37V. So this means that each battery is at about 4.185 volts. That’s pretty good and pretty high. Some other brands have a lower finishing voltage to be on the safe side, at the cost of peak performance.

Charging goes with the included USB-A to USB-C cable, and I measured a max charging current of 2.1A at 4.98V, so about 10.5Watt.

I tried to use a USB-C to USB-C cable with my USB-C power adapter, but that didn’t work. I also tried the USB-C port on my desktop, and it charged the light just fine, at the same current as of the USB-A to USB-C cable. During charging, the backlit switch breathes. This means that the light will fade in and out. It turns solid green when the charge has finished.

Power bank feature

The power bank feature can be a lifesaver. It will charge any device, as long as you have the correct USB cable with you. I charged my phone, and it showed a peak charge current of 1.5A but settled at around 1.18A. I also tried to charge a flashlight (the Nebo Slyde King 2K) and it charged at about 500mA. That’s just a bit lower than the 700mA, the Slyde King can take from a standard USB power adapter. I know, it’s kind of useless to charge a flashlight with a flashlight… lol

Lumen measurements:

All output numbers are relative to my homemade Integrating Sphere. It is set up with an Extech SDL400 Lux Meter for measurements including a Kenko PRO1D ND-16 filter. The base measurement is done with a Convoy S2+ that has been tested at 255 lumens.

For Amp readings, I use a Fluke 77III DMM. For higher amps I now use a Fluke 325 True RMS clamp meter. For microamps, I use a cheap DMM with an easy-to-use micro amp setting.

I used the included batteries, and measured only High and Turbo with my clamp meter. I used the widest beam setting.

I calculated the loss in light when the flashlight was zoomed in. This was about 40-45%, even at a so-called 2x zoom. But the zoom wasn’t really zooming to be honest. I’ll soon show the pictures and measurements.

My measurements were pretty close. As you may have seen, the output starts to slowly increase from turn on. The 30-seconds measurements in Low, Medium, and High are higher than at turn on.

Turbo was able to reach above 12,000 lumens, directly after charging the battery, and cooling down the light with a fan, before testing.

You should always keep in mind that the highest outputs of these lumenmonsters are dependent on many variables. Just to name a few:

• When the battery was charged (It provides most power, directly after it finished charging. If you wait a few days or a few weeks, it won’t be able to reach the highest possible output)
• Ambient temperature (putting a high power flashlight in front of a fan for a couple of minutes before gives the best results (I normally don’t do this, but sometimes, when I need to do multiple tests, I use a fan between the tests).
• Flashlight temperature. If the flashlight is warm, or even hot, it won’t reach its maximum output
• Battery state: older batteries, and used batteries, can provide less power at peak

Parasitic drain:

• 80 µA
  • This is pretty good

Nebo 12K runtime test (battery life)

The runtime test was done with the 50cm integrating sphere, including the Kenko Pro1D ND-16 filter and Extech SDL400 data logging Lux Meter.

It’s hard to measure Turbo mode correctly because you need to hold the switch to ramp to Turbo, but it also drops directly, so the time interval of the Lux meter (at 5 seconds) is not the best to see the actual peak performance.

Within 40 seconds was Turbo reduced to an output of 6600 lumens, and then slowly decreases output till it reaches 1150 lumens within 7 minutes. After 10 minutes it produced 1135 lumens. After 1 hour it’s 950 lumens.
The total runtime according to ANSI FL1 standards is 10% of 11631 lumens, which is already reached within 10 minutes. But as you can see, in normal life, that doesn’t mean the output finished being useful. At 5h05min it finally turned off.

High mode started at around 6360 lumens and slowly increase before it started dropping. After 6 minutes the output is down to 1600 lumens. Then at 22min there is another drop to 1000 lumens. At the 5h17min mark, the last measured output was 217 lumens before it turned off.

Medium mode: Turned off at 5h45min

Low mode: finished at 23h34min. The last measured output was 21 lumens before it turned off.

Throw Measurement

Measurements were taken indoors at 30seconds (unless shown as: at turn on) with a professional Hagner E4-X Lux Meter. Numbers were taken 30 seconds after turn on.

Just before the 30 seconds mark, Turbo starts dropping … so it’s hard to get the exact measurement at 30 seconds. Because for Turbo mode, you have to turn the light on (in High) and ramp it up, which could reach Turbo just 1 second earlier or later.

Anyway, here are the numbers;

The table needs some explanation. I used the number of meters in the Spec column because that’s what Nebo shares. So you need to compare Specs with the column Meters.

When it says Zoomed, it means that I focused the beam as much as possible. Nebo calls it 2x zoom, but as you can see, that doesn’t make sense. It’s not reaching 2 times as far, nor does the candela double (double the candela, doesn’t mean it reaches 2 times farther. You need 4 times the candela to reach 2 times farther). If you look at High mode, the candela went from 6,625 to 8,550, which is about 30% increase in candela. In terms of distance, let’s take High mode again: 163 meters vs 185 meters = 13% increase. So I don’t know where the 2X focus comes from.

I measured Turbo 4 times. (zoomed in and zoomed out, and at turn on and after 30 seconds) just to give you a better overview.

For the following beamshots I used a Canon EOS 5D Mk2 and a 50mm lens. manual settings: ISO1600, 1/4sec , F4, 5000K

The shed is about 65 meters / 71 yards away, and the reflective fence 200 meters from the camera.

You see that the zoom feature doesn’t make much of a difference. In my opinion, they could have left the zoom feature out.

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