is there no hope for protected rechargables for the latest version U2?

since the latest batch of SF U2 has smaller bodies, has anyone successfully use protected rechargables with it?

or is it now 100% non rechargables for the SF U2?

:huh2:

I'd guess you could still use a 17670 cell just fine. You won't have as much capacity as you do with an 18650, though.

You could also find someone with a lathe to bore it out for you, but you'll lose the chemcoat on the inside of the tube.

Ty_Bower said:

I'd guess you could still use a 17670 cell just fine. You won't have as much capacity as you do with an 18650, though.

You could also find someone with a lathe to bore it out for you, but you'll lose the chemcoat on the inside of the tube.

Click to expand...

hi Ty_Bower,

no boring

how much lumen output will the 17670 have?

Miracle said:

hi Ty_Bower,

no boring

how much lumen output will the 17670 have?

Click to expand...

The cells don't have "lumen output", but perhaps you are talking about their rated capacity. If you look at AW's sales thread for rechargeable LiIon cells, you will find:

- Protected 18650 ( 2200mAH ) ---- $12.00 each
- Protected 17670 ( 1600mAH ) ---- $10.00 each

So basically, the 18650 cells have about 38% more energy stored (for a 20% increase in price you get 38% more capacity - a bargain in my eyes), which will give you noticeably longer runtimes. In my humble opinion, given this dramatic increase, boring a new U2 to allow 18650 protected cells is a "must" in my book

Will

Has anybody bored out there U2 to accept the 18650's? Has it been done successfully?

Miracle said:

since the latest batch of SF U2 has smaller bodies

Click to expand...

uhm... do they really have a smaller inside diameter, or are you referring to the plastic sleeve inside the batterytube??

The plastic sleeve can be removed to accept 18650 size li-ions...

If they really made the batterytube smaller... that would make the U2 a bit less attractive to buy... They should fix the know issues like tailcap, lint and beam problems before 'fixing' the rechargeable 'problem'...

as far as i know there isnt a tailcap issue.... once you pull up the tabs, it will work just fine. There may be some lube issues with the tailcap, but those are uncommon.

-david

I'm using 17670s on my newer u2 and am satisfied. It lasts just as long as primaries on the highest setting... on the lowest it lasts about 30 hours vs 40 for primaries. There are runtime charts on 17670s somewhere but I lost the link. You don't really need protected since supposedly the u2 cuts off before overdischarging the cells.

May, the newest incarnation doesn't have the plastic sleeve anymore; the battery tube ID is smaller, not allowing the use of 18650's.

Tailcap and lint problems have been taken care of (unless you buy older stock, of course).

Boring the tube... :thinking:

i really wouldnt worry about not being able to fit 18650s... the graph with pila 168s is just about as good as with primaries. :

http://www.obaq.tv/cpf/?page=SureFire_U2

-david

Ah, that's the link I was looking for. Two 17670's (AKA 168S) with a DSD charger and you are good to go, it's still a very nice setup.

cheapo said:

i really wouldnt worry about not being able to fit 18650s... the graph with pila 168s is just about as good as with primaries. :

http://www.obaq.tv/cpf/?page=SureFire_U2

-david

Click to expand...

True, but even longer runtimes with the 18650 cell

This is just one of the many, many accounts of long runtimes of the U2 with the 18650 cell here in the forums

The U2 is a fantastic light, but it is trully "perfect" with the 18650 cell.

Will

Stop rubbing it in! :mecry:

thankz for all the info.

can some kind souls please confirm that the latest version of the U2 'will' accept 17670?

with the 17670 will it still give out 60+ lumens?

:huh2:

greenLED said:

May, the newest incarnation doesn't have the plastic sleeve anymore; the battery tube ID is smaller, not allowing the use of 18650's.

Click to expand...

sigh... what is this world coming to....

Yes, it will accept them.

wquiles said:

So basically, the 18650 cells have about 38% more energy stored (for a 20% increase in price you get 38% more capacity - a bargain in my eyes), which will give you noticeably longer runtimes. In my humble opinion, given this dramatic increase, boring a new U2 to allow 18650 protected cells is a "must" in my book

Will

Click to expand...

but... Since the 17670 will give you similar runtime to the Primary 123as, I wouldn't make this a requirement or deal breaker.

If the new U2s have the same emitter as that I just got in a new KL4 ( which is right there with the Wbin I put in the U2), I'd be more than happy. The KL4 is right at the heels of the U2 and that is amazing since it is driven at ~860ma and the KL4 are supposedly in the 660ma range (I haven't tested one so...)

Bore out the U2. All of my C/M/Z series are bored out to take 18650's which can be had with 2400mAH capacities. 17670's have 1600mAH so going from 17670 to 18650 is a 50 percent increase. I'm not sure why Surefire does not want anyone to use 18650's which is too bad because they now pack more energy in a single 18650 than two CR123's :shrug:

whoa

i did a search and found this....

the U2 has better throw and is brighter then the Kroma?

will this also be the case with the final version of the Kroma?

:wow:

i thought the Kroma uses a LuxIII and not a LuxV like in the U2?

anyway they are both quite different... the U2 has multiple light levels but is more utiliatrian. Kroma definitely has more functionality & possiblities for various uses

anyhoo it'd seem that the old 18650 accepting U2s just increased in worth