Can 3 x Cree XM-L T6s output 4000 Lumens on 2 x 18650 Li-ions, or is this China bull?

I have just seen a flashlight for sale in China that states with 3 x XM-L T6s on 2 x 18650 Li-ions that it punches out 4000 lumens.

This does not add up to me.

I have an Apex 5 x XM-L T6 light and it is only rated at 3000 lumens but when put side by side against my 2000 lumen Skyray King it looks hardly any more brighter.

Is this a Chinese marketing tricks at work again or could this be possible given the laws of LED outputs?

How can you believe any specification that Chinese manufacturers claim anymore?

What is the maximum lumen limits for running 3 or 5 XM-L T6s on any amount of batteries?





CHEERS

what light is it? and what are the emitters driven at?

4000 lumens from 3xmls - they would each have to be driven at somewhere around 4-4.5 amps each which i doubt

Oztorchfreak said:

I have just seen a flashlight for sale in China that states

Click to expand...

The correct response to this input is, "it's false."

jmpaul320 said:

what light is it? and what are the emitters driven at?

4000 lumens from 3xmls - they would each have to be driven at somewhere around 4-4.5 amps each which i doubt

Click to expand...

It is a SKY RAY 3T6 M8 3xT6 Cree XM-L T6 Stainless steel 4000 Lumen 5-Mode Led Flashlight.

This is similar to the "1600" lumen single XM-L lights, or the 18w LED lights back when Luxeons were king., or the current XX Candlepower spot lights. Just big false numbers to attract unsuspecting shoppers.

An XM-L directly soldered to a copper heatsink can hit 1500 lumen at 6 A, so to get 4000 lumen out the front, the optics have to transmit at least 88.9% of the light from the LED to out the front, could be doable with really efficient reflectors or TIR optics.

Realistically, the light probably hits 1000-2000 lumen out the front depending on the actual LED bins being used and how hard the LEDs are driven.

yeah. 3 XML skyrays are all around 2000 real lumen. anything higher is marketing hype, or
they are lost in translation about Lux or candlepower but write it down as lumens

I have a king that is around 2000, but depending on the website I see it on, it is advertised anywhere from
5000, 4500, 4000, 3500, 3000, 2500 lumens.

The chances of any marketing claim for that light being anywhere near accurate are about zero.

Are they emitter lumens, or out the front OTF lumens which are lower due to reflector and lens losses?
An XM-L emitter, even in the latest U2 bin, at 3 amps has a max output of 975 emitter lumens.
If it was driven above 3 amps, it may produce more emitter lumens.
So, with three emitters, we are looking at 2925 emitter lumens on an U2 bin at 3 amps each.
The T6 bin is 7% less than that total of 2925 emitter lumens.

It is possible that a triple XM-L T6 is outputting 4000 emitter lumens, which is more than 30% greater than the normal maximum, by being "overdriven" past Cree's recommended 3 amps each, but this is very unlikely.
If it came from a specialist builder like Saabluster etc, who uses expensive and superb heat sinking with copper heat sinks and thermal paste etc, then this is very possible...

5 Amps to an XML soldered to copper will get you over 1400 lumens OTE. So it is possible if they're talking OTE Lumens. I have a Skyray Triple coming, and my Vinhnguyen copper soldered LED's have arrived. I have a Vinhnguyen P60 drop-in that's driven at 4.8 Amps and the thing rocks! My intention is 4000 OTE and about 3300 OTF. I seriously doubt the China light you are referring to went to the trouble/expense of copper/soldered LED's. But yea, it is possible.

There is no way they are getting 4k from 3 XMLs, Its a total puff of hot air!

99% of the Chinese lights are made as cheaply as possible. This means what ever bin emitter they can get ( I think some even lie about the bin) so maybe T6 at best. They are NOT soldering emitters to copper. The wire in them is usually thin and cheap so often times the emitters are not even driven to a full 3A

Based on my experience ( building XM-L flashlights using top bin emitters from a reputable source and then having them tested in a calibrated sphere) I'd say best case scenario a cheap Chinese light with 3 XM-Ls will test at 1800 lumens.

I googled that light and clicked the first link that came up. It said 4000 lumens right in the title. Then I saw a little box under the picture that said "Error report", so I clicked it. Then it asked me where the error was so I told them. Its in the description where you said that flashlight puts out 4000 lumens. LOL!!!!