No I didn’t change the driver, bike lights utilize 6V emitters, run from two 4.2V cells in series.
Guess I incorrectly assumed that because the OP’s flashlights were XM-L2 they were also 6V and run from a boost driver. Didn’t know there were any 3V XM-L2 emitters.
Well the 3V XHP50.2 would certainly be more efficient, just that the only ones available retail right now are 6500K.
Sofirn just released their SP33V3.0 in 5000K, says XHP50.2 so those emitters do exist in 3V… somewhere.
Problem is, even a 2:1 improvement in efficiency would hardly be that noticeable visually.
And a higher Vf might pull it out of regulation faster (and v/v), and/or be more limiting if DDed.
Me, I wouldn’t bother for such negligible gains.
As others have said, only if you swap the driver. The difference between the XML-2 and sst40 really only come into play over about 4.5 to 5A drive currents. Up to that the outputs are virtually identical. That goes for runtime as well. The XML-2 max drive current is around 6A, while the sst40 can be driven harder, safely up to 7.5 or 8A with good heatsinking. Even at 5A, that sst40 pushes 1700lm. The vf will be lower, and that’s how you can drive it hard. But, you need a good battery (sony vtc6, samsung 30q, or LG H2), and bypassed springs to get the most out of it. Not to mention good heatsinking as that sst40 cooks at high current. I had a pretty beefy zoomie host I ran one in on a fet and boy after a minute it got uncomfortable.
You can run a xhp50.2 3v off the sst40 driver as well. Less throw, but you can get 20% more output from the xhp50.2 at the same drive current as sst40.
The runtime is much better with 21700 and don’t need to mod the driver for a turbo mode.
Yea, I was thinking the same thing.
Thanks
For the most part, I think the days of “Hmm, everything else in this light sucks, but this’d make a great host” are gone.
I know I wasn’t in any itchin’ hurry to mod a light in a long time.
Are there high CRI XML2 emitters available anywhere?
Yes, I have a 3000K 90+ CRI XM-L2 in a couple of lights and the tint is very nice.
I have used that bin in a JetBeam infinitely variable rotary. I really like it. It will happily tide me over until the XML3 becomes available.
Thanks Sirstinky your post was very informative and helpful!
I’m also considering upgrading some older XM/XP lights with SST40 and xhp50.2 , but I’m okay with swapping drivers on some to get the increased output.
I noticed the newer high output SST-40 Convoy tube lights are running a 5A or 6A driver, opposed to the 2.8A (max) drivers they use for XML/XPL. Convoy sells several versions of 5A and 6A drivers, some with temp control. I’m considering their 6A driver w/ramping for smaller lights for increased output of an SST40 while still having regulation, and a MTN FET-DD for larger lights or hot rods with better heat sinking.
I actually had that driver until I upgraded to a Mtn. 17mm fet+1 because I couldn’t live with the firmware. Beware that it isn’t ramping, it’s stepped dimming with 2 other modes. It can do about 7A with a VTC6 and spring bypasses. At 7A that sst40 is 2000lm in high bins 5000k. No other single die emitter aside from the SBT90 can match it at that drive current (or heat production).
A bit more info on that convoy driver.
I’m a big fan of this driver. A lot of people don’t like the UI, but I don’t think it’s really very different from a “normal” clicky UI. It has 3 modes. The main difference is that it has what is essentially “short cycle memory” where when you are in any mode and you tap the switch it starts back at the first mode. So if you are in the first mode and want to go to the second mode, normally you would tap the switch once, but with short cycle memory you tap it twice.
The real advantage and uniqueness of the driver is its customizability. You can pick any regulated current you want, from 80mA to 8A, for the first 2 modes. The “ramping” is just used for this customization step. The third mode you can unfortunately only choose from a few different options including 1, 100, strobe, beacon, sos…
I am really liking them for bike lights where I can tune the exact current I want to get the highest brightness for my rides. For example I use 3A for 18650 lights and will use 4.5A for 21700 lights. All with the same driver without needing to stack/destack 7135s.
Thanks for the info, I haven’t really read through all the options but I had no idea the outputs were adjustable! So it doesn’t have ramping or stepless dimming, just 3 modes. That’s fine, and I like that the first mode can be 100%.
you need XML3
Barry, some time ago Cutter has said that XML3 was on the way and not much more. Do you have any more info?,
Luxeon V can do 2000 lumens at 7A and the tint is quite a bit nicer than the SST40.
Thanks, tint is a concern so I will look into this.
I remember someone mentioned XML3 were announced a few months ago.
If you have more info, please let us BLF members know !
Hope it’s not a flip-chip with hideous angular tint-shift like the G3…