# What is the max achievable lumens from a CREE XM-L T6 LED?



## Surefyr (Mar 26, 2012)

Hi! I am new to technical things here about flashlights. But can anyone explain, how a Four Sevens Minix 123 produces 210 OTF Lumens using a single CR123 cell and CREE XM-L T6 LED combo (manufacturer advices not to use rechargeable RCRs which are 3+ Volts), whereas a Ultrafire CREE XM-L T6 does 900+ Lumens out of a Single 18650 cell (3.7 Volts). Both uses the same CREE XM-L T6 LED. Does it mean the XM-L T6 LEDS are able to produce more Lumens if driven harder? If so, how much is the max Lumens that can be achieved with a Single XM-L T6 LED without damage to the lamp?


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## flashflood (Mar 26, 2012)

Surefyr said:


> Hi! I am new to technical things here about flashlights. But can anyone explain, how a Four Sevens Minix 123 produces 210 OTF Lumens using a single CR123 cell and CREE XM-L T6 LED combo (manufacturer advices not to use rechargeable RCRs which are 3+ Volts), whereas a Ultrafire CREE XM-L T6 does 900+ Lumens out of a Single 18650 cell (3.7 Volts). Both uses the same CREE XM-L T6 LED. Does it mean the XM-L T6 LEDS are able to produce more Lumens if driven harder? If so, how much is the max Lumens that can be achieved with a Single XM-L T6 LED without damage to the lamp?



Yes. Max output is about 1,000 lumens at 3.2A. You can actually drive it even harder, if you can cool it, but with rapidly diminishing returns.


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## jorn (Mar 26, 2012)

> If so, how much is the max Lumens that can be achieved with a Single XM-L T6 LED without damage to the lamp?


 Depends on how big the light is. Small lights like the quark minis, cant cool the led if it's driven at max. Tempratures rises and the lumens drop. 

The ultrafire don't got 900+ lumens, they claim its 900+. Big difference. Normally a xm-l is about 6-700 real lumens out the front (after the reflector and lense have eaten some of the lumens)..


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## texas cop (Mar 26, 2012)

The electronics "Driver" on the led are set to run on certain voltages commonly used are 2.5-4.2, 3-6, 3.5-9 this is done to try to get the best efficient use out of the power supply. If the lights says only 3volt cr123 stick to it, 4.2 volt rcr123 might kill the led or the driver.


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## yifu (Mar 26, 2012)

Here's a test on the XML that Saalbuster (maker of DEFT) did last year. Maximum output is around 1400 lumens at 6A but without a good thermal pathway you wont be able to maintain it. A TIR optic is about double the optical efficiency of a normal reflector (non electroformed or rhodium plated) so you can expect 900+ lumens OTF with 3.5A or so.


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## yifu (Mar 26, 2012)

Also i've had experience running a MiniX123 with an IMR16340. In a ceiling bounce, using a lux meter, it clocked in at around 500 OTF lumens at turn on. But heat and runtime would be issues. You don't need any mods to do this, just get an AW IMR16340 over at the marketplace(which is down right now). This would likely void your warranty.


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## jorn (Mar 26, 2012)

I also use the mini-x with 16340's . Use both Imr and normal protected aw 16340's, cant see any difference in output. It does void the warranty, and you can fry the led if you run it in high for too long. It's alot of light from a tiny light.


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## 127.0.0.1 (Mar 26, 2012)

max lumens is ~975 cree xml t6


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## andreavda (Apr 1, 2014)

127.0.0.1 said:


> max lumens is ~975 cree xml t6



funny because that's exactly what this seller says
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=221397379825&ssPageName=ADME:X:RTQ:US:1123

I guess that's because the seller is from Japan, if he was from China he probably would have said 3000 lumens xD

well that's quite a lot, it would set me back a lot more, maybe 5 times more, if I wanted to get a proper 900 lumen front light.


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## ven (Apr 1, 2014)

From the chart shown above,if driven at 1.7A as in advert, it would be around 650lm,actual OTF( out the front) would be less


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