Max output of XL-T6 with 1x 18650?

Hi guys, I just ordered a flashlight which fasttech claims to be 1000lm. then this guy says the max output is 975 lumens on a XML-T6, I goggled a little but found mixed answers, some say yes some say no. If it is really 900-1000lm that means the driver is set to 3A, won't that be an issue for that small host? It is powered by 1x 18650. TL;DR: can this flashlight easily reach 900+lumens without any or little issues while being powered by 1x 18650? Thanks

I believe at 3 amps the LED can be driven to slightly over 1000 lumens. OTF lumens are probably around 850-900 lumens.

Technically I guess you can overdrive the emitter as long as you can cool it. But in a small 18650 light that would be hard to do. The flashlight would have to have a decent size head.

The XML T6 can definately be driven to 1000 lm. However, the life of the emitter will be affected, heat will be an issue and battery life may be less than desired with 1X18650. You should probably go with the Panasonic 3100 or 3400 mAh 18650.

I have serious doubts that 1000 lumens OTF is realistically obtainable with a single 18650 using an XM-L T6. Most lights in that category seem to top out at about 750 lumens. There are a variety issues.
The driver isn't 100% efficient, so in order to get to 1000 lumens OTF you need to dissipate 12-15 watts, and that's tough to do for any length of time in small flashlight and tough to draw that level of continuous power from a single 18650. Even if you can , the run time at that level from a single 3100 mAh 18650 is likely to be on the order of 40 minutes. Even then it would probably be necessary to reduce the output within a few minutes to prevent the LED from being 'cooked'. Essentially all small high ouput LED flashlights incorporate thermal management to 'step down' the output in order to provide reasonable LED life.


I know that with a Crelant 7G6GS with a pair of CR123A and an XM-L U3, you can get a little better than 700 luments OTF. I'd rate the prospects of 1000 OTF lumens from an XM-L T6 and a single 18650 battery as nil and 900 lumens is very suspect. When it comes to rating output from flashlights, once you get away from the established names, there is a lot of wishful thinking, and much of it is well beyond the realistic limits of the LED, Battery and heat sink capability. At this point XM-L T6's are well 'behind the curve'.

Even with an XM-L2 U2 with a single 18650, 1000 lumens OTF is just barely possible, and I don't know any of the 'big names' that offer such a capability. That suggests to me that it isn't easily accomplished, otherwise it would be offered for sale. If it looks to good to be true, odds are it IS to good to be true. So if you are expecting to get 1000 lumens or even 900 lumens for more than a few minutes at a time out of an XM-L T6 with single 18650 in a small body, disappointment is virturally guaranteed.