Luminus SBT-90 gen2 5700K tested (SBT-90-WDS-F72-SA600 SA-H4, from Neal)

Today I received one of the scarcely available Luminus SBT-90.2 leds from nealsgadgets, and tested it for voltage and output.

It is a single die 3V led with a large die area (3x3mm) that combines high output with high luminance, which makes high output and far throwing flashlights possible. Luminus is slow with datasheets, I do not think there is one yet for the gen2 version. Edit: JaredM posted a link to the datasheet that I could not find:

GEN2 datasheet

For the test I used a 20mm diameter MT-Noctigon that is not a perfect fit but will not limit the performance of this led.

The reflow was not without problems. I started with too little solder paste so the thermal pad was not completely covered with solder and the led did not sit flat enough on the board. I removed the led, added more solder paste and reflowed again. Now all was good.

Here is the led at 1mA current, showing the very uniform luminance of the die, this led will create nice beams!

The output test was done like most of my emitter tests over the last years. I described it in detail in my XP-L test (found via my sigline), with the minor difference, that should not matter significantly for the results, that I used my Integrating sphere no. II instead of no. I.
In summary: 1) just one led of each type was tested, reflowed on a DTPcopper board 2) I used my large version II integrating sphere with high quality luxmeter, 3) the output numbers and voltages were measured with the led close to ‘steady state’ for each current, so warmed up and settled (I take a minute before each current increase), you should be able to get these numbers in a well heatsinked flashlight. Mind that these are output numbers of the bare led; in a flashlight there will be losses from light obstructions, lens and optic, 4) output is in ‘djozz-lumen’ defined as 1/550 of the output of my Sunwayman D40A on high setting, which I hope is close to the real lumen (recent comparisons show that it is actually between 7 and 11% high), but at least is consistent over all my previous emitter tests done in integrating spheres, so all my output data over the past years can be directly compared.

*again, mind that the djozz-lumen is probably somewhere between 7 and 11% high compared to the real lumen.

*this is a very high output led running at 66W at 20A, my other tests with leds with this high output suggested that the heatsinking of my rig limits the output a bit when at max. But in an actual flashlight build it will probably no different.

*at high currents, the voltage drop over the ledwires becomes significant, for the ledwires (length and type) that I always use for led-tests I measure a drop of 21mV at 10A current. So at 20A and two ledwires that is 84mV so almost 0.1V. If I was thorough, I could substract that error from the measured numbers and get you the correct voltage at the solder-joint. But I am not that thorough.

*my power supply goes up to 20A, so higher currents were not tested. As you can see in the chart, the max was not reached at 20A, but it seems also not far from max. It would be nice if someone with a PS that goes higher than 20A could test the behaviour at higher currents.

*I did keep the led at 20A for 15 minutes and it stayed rather happy at that current, the output drop over 15 minutes was about 1%. Directly after switching the led off I measured the temperature of the led with a ir-thermometer and measured 45 degC. But it would have been a bit higher because a led is not a matt black object.

Conclusion: this is a power-hungry led with at maximum power a great output (and thus great luminance given the only 9mm2 die) but at 20A not great efficiency, 72lm/W (but who cares about that :slight_smile: ). Edit: the 175lm/W at 1A is much better.


Edit Jan26, some tint information in post#22

1 Thank

Great test! I was really curious about this LED.
Thanks a lot djozz!

Thanks :+1:

Thanks. This LED is a beast!

What’s the color like? Based on the sbt-90 gen 1 info, if the binning is similar it seems like it might be a bit green.

Thanks a lot djozz. May I get some raw data please?

Thanks a lot, good to know.

Definitely the Uber-Boss led.

At last :+1:

Thanks for the great test

regards Xandre

The second batch NI40 I got from Neal had a nice tint. As you can see in the picture below the FT03S is more yellow/green at all levels. Also seen a picture on a Chinese forum which shows the same thing. Not sure if this has anything to do with the reflector/lens. Probably just the batch of LEDs.

I will do some tint measurements too, had no time for that yesterday, maybe this evening. But if the tint is not properly specified, depends on from who you got it, and then the led is sold out there anyway, apart from satisfying some curiosity it is not data that is very useful.

Lost on the tint lottery with my K30-GT. In actual use it’s obviously not quite as noticeable as when white wall hunting, but I do still wish it was less green. Despite the tint, I really do love the beam profile on this light.

I removed the window/lens from my 5th SBT-90.2 and put it in a light, very impressive, any plans to do the same for scientific purposes… :wink:

Ehm, not really, my “science” is still on a ration for the next 12 years (wife,child) and I have plans for this led :slight_smile:

So what is the impression of removing the window?

Tint is usually better with the AR window removed. I’ve been taking em off SBT-70’s for years now.

How tight is that black frame that the window sits on? In my mod I’m planning to ream the reflector so that it fits precisely around the frame. But it must not be sheared off the first time that I drop the light and the reflector applies sideways force on it.

It could just be the best performing SBT-90.2 I have tried so far….I don’t know? But here is what I got….

a. Warmed up the tint a bit…

b. Went from 358kcd to 408kcd (Original FT03 SST-40 GB Light)

c. Went from 5000lm to 5780lm at T/O (after I checked the throw so it was still pretty warm and battery drained a bit)

Sounds good. It looks like an uncoated window so I would expect maybe 5% loss from it, so the gain is a bit higher than you would expect from just the window.

Any comments on how rigid that black frame was?

It is glued on fairly well. I used a Feather platinum coated blade and worked my way around the LED pad, slicing at the seal little by little and being careful not to power thru and cut the bond wires…or slice off a hunk of finger…the blades a super thin and sharp, just keep the blade on the LED pad just under the steel frame of the lens…


Are these available for purchase to the public yet? If so who is carrying them?

Wendy…she has 45mm MCPCB’s also…

. Shenzhen Lantend Electronic Co., Ltd | Room228, Block B,Wanyuan Business Building,Chuangye Road 71 Area, Baoan district, Shenzhen city of China

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. Neal of Neal’s Gadget’s had some too…