Surefire LFP 123A lithium-phosphate rechargeable batteries

Whats the deal?

Sorry for noob question but the subtle nuances of the whole battery thing is more than I'd like to do PhD type research into, I figured I'd take the lazy way out and ask you gentlemen.

I currently have about a dozen or so CR123a lights and would LOVE it if I could start using rechargeables, my first non surefire light is the Nitecore TM-11 with which I bought 4 panasonic 18650's and am very happy to have them. I would love to get rechargeables for all of my lights now and have been looking at getting some more 18650's and also some 16340's or (rcr123a's). My questions are I've noticed they all seem to have varying voltages/Wh's etc., are they at least semi-interchangeable? For instance could I put 1 18650 in say a surefire L2 instead of 2 CR123a's? or 2 16340's instead?

Are there any charts or comparisons that I could reference so I know which batteries are best to stock up on, which ones I COULD use, which ones could potentially do harm to my lights? etc, etc, etc???

thanks so much!
-Adam

Ps, feel free to blast me for my laziness and/or ignorance, as long as someone answers me

It's all in the battery section, e.g: http://www.candlepowerforums.com/vb/showthread.php?330236-2012-Battery-test-review-summary

For what is and isn't compatible with individual lights you will have to do some quick google searching. The Surefire 3.0v rechargeables are interchangeable with their primary cr123 cells and so a safe option recommended by surefire and compatible with all their lights as a direct replacement. However, in many lights you will get more power from other chemistries/cell sizes. Remember though that most surefire lights will not fit 18650s so you would need RCR123s which if traditional 4.2v max ones may be too high voltage for some to take, or 17670s/16650s which in most will run fine, but others may be too low a voltage to maintain flat regulation.

Thanks Red, it's just all so confusing, I wish we could go back to simpler days of batteries, where basically if it fit, it worked...lol...

I was just basically wondering whether the new surefire batteries were worth buying or I could get away with just stocking up on the CR123's, I hate the idea of having 10 different battery types for 10 different lights, makes things so much more unpleasant...

I just grabbed 50 Energizer primary 123's from battery junction for $60 plus shipping.
Rechargables are nice and all but sometimes you need to stash away primary cells just in case ...........

Ok, well as long as you don't have any single cell lights you can just get some protected 17670s (AWs are probably most consistent/reliable quality) or some 'Sanyo UR16650ZT' (search that) from intl-outdoor if you want an easier fit and slightly more capacity at the cost of protection circuitry. These should charge in an 18650 charger (I recommend the Xtar WP2 II) and can be used in the TM11. If you only have these two cell types then it really is a case of if it fits in the light you can use it safely.

If you list the lights you want to use RCRs in though I'm sure someone can give you a better recommendation.

Ok, for those incan lights you are going to have to stick pretty close to the designed voltage ranges I think. Also the M6 battery carrier is designed to only allow CR123 sized cells. So I would have to recommend Surefire's recommended 'K2' energy brand LFP rechargeables for those, 3.0v LFP cells will also be safest (no heat issues) for the RRT-01 too. 18650s are the best way to go for the TM11 for maximum capacity, though the LFP RCR123s could be used in a pinch too. You could get a 17670 for a bit more capacity than 2x LFP cells in the L2 (about 5.7wh for the 17670 compared to about 3.6wh for 2x LFP cells) but it probably isn't worth the hassle, even though it could be charged in the 18650 charger which I assume you have already.

Basically, to keep it simple just get some of surefires recommended (or other brand if you wanted to save a few $) LFP (LiFePo4) cells like you were planning to originally. Stick with 18650s for the TM11 and maybe consider 17670s for the L2 and any other 2 cell LED surefires you may have, but 2x LFP cells are fine for these too if you don't think it's worth the hassle.

For reference here are some estimated wh values for what you have and may consider.

Panasonic 3100 18650: 11.2
Surefire Primary CR123: 4.4
Surefire/K2 LFP RCR123: 1.8
AW 17670: 5.7

You see Li-ion (non-LFP) have in general higher capacity with the 18650 format being the most efficient size to power ratio out there due to the massive amount of R&D put into that size's development. This makes 18650s by far the best choice for the TM11 with such high current draw. For your other lights however most will need an equivalent to the original primaries they were designed for, apart from 2 cell LED ones which can be replaced with 4.2v max li-ions in most cases as the LED vf is below the working voltage of a li-ion anyway (but only with ones that will fit in the tube!).

What's up with Surefire selling Chinese rechargable batteries when they say to only use US batteries?

Raptor Factor said:

What's up with Surefire selling Chinese rechargable batteries when they say to only use US batteries?

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Not sure if they're Chinese, but they're just filling a customer need. The world's worst kept secret is that Surefire's regulated lights will happily work with rechargable batteries. Surefire jsut hasn't supported them until now. Considering the amount of variances in size, voltages, and chemistry safety that's out there, I don't blame them. By choosing one brand using a safer chemistry, they can now give users a choice of rechargables without having to support the wide variations out there.

To Adam2670: according to Surefire's web page on the K2 batteries here:

http://www.surefire.com/2-pack-lfp123-rechargeable-batteries.html

The use of K2 LFP 123A's is restricted to their LED illumination products:

Rechargeable LFP 123A batteries are only to be used to power LED illumination
products (built to use 123A lithium batteries) and NOT those featuring
incandescent lamps. The initial elevated voltage of these rechargeable
batteries, immediately after charging, may cause the filament contained within
an incandescent lamp to break or "burn out."

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That pretty much means your M4 and M6 are not supported by Surefire to use these batteries.

[h=5]Where are these rechargeable LFP 123A batteries manufactured? - They are made to our specifications in China. http://www.surefire.com/faqs#rechargeable[/h]I guess it's not that big of a deal but you would have really thought Surefire would have gone american when they finally came out with some rechargable 123's. Are there even any american made rechargeable 123's?

I just with Surefire had them in stock! I called them yesterday and they said it would be about another month. Called every authorized dealer in driving distance and they act like they don't know what I'm talking about.

tonywalker23 said:

I just with Surefire had them in stock! I called them yesterday and they said it would be about another month. Called every authorized dealer in driving distance and they act like they don't know what I'm talking about.

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I had the same thing with distributors here. They told me that it wasn't a surefire product as such, and that they weren't being imported into the country yet. They then tried to sell me a Panasonic 18650 battery as an alternative.

I wonder if they would have warrantied the lx2 I bought from them if I tried to install the 18650 into it.

Anywhere to get these other than K2 or Surefire?
They are $6 each in both places and I was hoping for a better price..
I don't want another brand since Surefire has OK'd these for use in their flashlights and I don't want to risk the lifetime warranty.

Also, it say's they are good for 2000 cycles. Is that realistic?

Has anyone used AW's LFP123A batteries in Surefire lights?

I'm also interested in finding out if there is a rechargeable 123 type battery that outperforms the SF LFP123. I have an X300Ultra that runs two 123's side by side in series. I can't get anything else in there so want the best rechargeable 123 type possible, just not sure if SF's battery is it or if there is another that would be better.

I tried to find the SF LiFePO4's in stock but couldn't and stumbled across some Tenergy LiFePO4's at Amazon for a very good price with the charger. For the past couple of months they have worked well in the SF lights that wouldn't take AW RCR123's or in some cases an AW 17670.

However, like everyone else I would like to avoid carrying another charger.

I am curious if the Tenergy's are the same Chinese cell as the SF LFP's.

Adam2670 said:

Sorry for noob question but the subtle nuances of the whole battery thing is more than I'd like to do PhD type research into, I figured I'd take the lazy way out and ask you gentlemen.

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There are indeed some very learned dissertations in the 'Flashlight Electronics-Batteries Included' section of CPF.

No, they're not. K2 (Surefire's manufacturer for these) makes pretty high quality stuff.

write2dgray said:

No, they're not. K2 (Surefire's manufacturer for these) makes pretty high quality stuff.

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How do the K2 and Tenergy cells differ? Or, are you just assuming K2 would use a different Chinese cell since they make 'pretty high quality stuff'?

So far I've had good luck with the Tenergy LiFePO4's.

Tenergy LiFePO4 123A's claim "750mAh" and have minimum capacity 450mAh, but K2 Energy LFP123A's are 600mAh with minimum capacity 550mAh. Even if they do come from the same manufacturer, the cells aren't made to the same specifications.

I've never heard of K2 Energy before SureFire came out with the rechargeable kit, so I had looked into Tenergy LiFePO4 123A's. Based on the number of complaints about dead cells and reliability issues, I decided not to take the chance.

Robin24k said:

Tenergy LiFePO4 123A's claim "750mAh" and have minimum capacity 450mAh, but K2 Energy LFP123A's are 600mAh with minimum capacity 550mAh. Even if they do come from the same manufacturer, the cells aren't made to the same specifications.

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Not sure I would base that comparison solely on spec sheets posted by the marketing department from what we have seen of other product claims for flashlights and batteries. :devil:

Hopefully someone will get both batteries and test and take a close look at the construction under the label.

But, I hope you are right and the K2's are worth the extra money and we are not paying extra only for the K2/SF name.

Tenergy's brand has been in the public eye recently in an unfortunate product application :

http://www.newsmax.com/TheWire/battery-boston-marathon-bombing-tenergy/2013/04/18/id/500153