Surefire U2 - Missing 3 of 6 Power Levels

The light has been a workhorse. I've EDC for the better part of 4 or 5 (or 10, memory fails me) years and have used it fishing, camping, you name it, it's probably been with me experiencing the potential life an EDC light is expected of . I've had the original Luxeon V emitter gone through two iterations. Once with a Seoul P4 and lastly with a Cree XML. Looking back, it may not have been a wise choice putting those emitters, but I've yearned for more power. I don't recall exactly when, but shortly after its first transplant, it lost a couple power levels. It may have went from levels 1 through 6 to something like 1, 3, 4, 5, 6 to finally 1, 3, 5. It munched on 18650 most of its life.

Have you folks experience the same agony of a loved one losing such bodily functions and is there a remedy in her future? I am willing to do whatever it takes to keep her with me.

Were additional modifications made to the voltage/current? If not, don't count 'er out yet. Here's my diagnosis -

I believe the Luxeon V is a 6 Vf emitter whereas the Seoul P4 and Cree XM-L are 3 Vf emitters, this may account for why the loss of levels (and crazy brightness from way over driven emitters).

Assuming there hasn't been any damage done to the driver/electronics, try dropping one of the new Cree XHP-50's in there and you should have (a) more lumens and (b) all 6-levels back.

Good luck.

I replaced the Luxeon V in my U2 a few years ago with an XML and it work ok... shortly after the XHP50s release I installed one and the world is great! I run it on 18650s without issues. [emoji106]🏻[emoji106]🏻[emoji106]🏻

I have tried two 18350s... two lower levels and then full boogie!!! Not measured the output but it competes with my Oveready v5 drop in on afterburner. [emoji15]

I know I've probably used up all my luck with those few experiments so it is only fed 18650s or if need be the occasional CR123s these days.

[emoji41]

PC light is correct. The Lux V is a 6v emitter and the Seoul and XML are 3v emitters and that may have something to do with the levels.

The XPH-50 is the best 6v emitter choice at this time IMO.

I was also thinking of putting an XHP50! I hope the loss of power levels isn't to do with the Hall effect sensors. That part of the light is sealed and I don't think I can get at it. No mods were made to the drivers.

I'm quite surprised the XML had lasted this long to be honest. She sure is bright though :thumbsup:

Nitroz is a first rate modder of U2's, but wanted to mention to other possible owners of the venerable SureFire U2 that Oveready has an adapter that will allow P60 dropins to function with the U2 body. That opens a lot of options. $38

KITROBASKIN said:

Nitroz is a first rate modder of U2's, but wanted to mention to other possible owners of the venerable SureFire U2 that Oveready has an adapter that will allow P60 dropins to function with the U2 body. That opens a lot of options. $38

Click to expand...

I have and use the adapter with an Oveready/Torchlab v5 drop in on my U2 body. It's a great way to use the really nice U2 body and clip and crank out lots of lumens. Switching between the U2 head and the adapter is a wonderful option. Just upgrade the tail cap to a McClicky compatible one. [emoji106]🏻[emoji106]🏻[emoji106]🏻

KITROBASKIN said:

Nitroz is a first rate modder of U2's, but wanted to mention to other possible owners of the venerable SureFire U2 that Oveready has an adapter that will allow P60 dropins to function with the U2 body. That opens a lot of options. $38

Click to expand...

I've been out of the scene for some time and not familiar with the lingo. A search didn't show the adapter for the U2. Can you point me in the right direction?

In any case, have anyone here able to take apart a U2 head completely? Like right down to the drivers. I'm wondering whether it is serviceable.....

Nitroz may have the most experience accessing the U2 innards.

oveready.com
then parts, I believe, then adapters. If you go powerful, take U2v5's advice and go with a switch that can handle more amperage.

Oh god, what have I gotten myself into.... I spent the better half of last night on the forum learning about new lights and mods I can do to the U2 :duh2:

Now I've got the itch to mod the L1 and L2 also....

Good Times

These are such iconic, sturdy flashlights. They deserve a new lease on life.