# RCR123A 3.0V or 3.7V



## dusty99 (Jan 8, 2013)

I have an Eagletac D25C and like the modes the way they are now, and to not worry about the heat generated with longer runtimes using a RCR123a 3.7V, but I'd like to run rechargeables. Any thoughts about the 3.0V versions? Since the ones I've seen online seem to be 3.7V batteries with internal regulation, can I charge them with my XTAR 4.2V charger?

Thanks!


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## LilKevin715 (Jan 8, 2013)

http://batteryuniversity.com/learn/article/types_of_lithium_ion

LiPo aka Lithium Phosphate has a working voltage of 3.0-3.3v, with a fully charged voltage of 3.6v. You didn't state what model Xtar charger you have... only the MP2 can charge LiPo cells. All the other xtar chargers are designed to charge LiNiCo or LiCo aka Lithium Cobalt cells (3.7v working, 4.2v fully charged).


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## Shadowww (Jan 8, 2013)

Please don't mistake LiPo (Lithium-Ion Polymer) and LiFePO4 (Lithium Iron Phosphate) cells.
3.0V / 3.2V cells are LiFePO4, not LiPo.


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## LilKevin715 (Jan 8, 2013)

My bad, I knew I forgot something:thinking:


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## dusty99 (Jan 8, 2013)

Thanks, but I'm not considering LiPo or LiFeP04 batteries. The ones I'm looking at are evidently 3.7V Li-Ions that run at 3-3.2V. Tenergy and others make them. Here's a seller's description:



You must use the 3.0V RCR123A Li-Ion 900mAh battery charger linked below to charge these batteries.
Please do not use other charger, including any 3.6V Li-Ion bttery charger, which can not full charge the 3.0V Li-Ion batteries.
We do not recommend this setup for any SureFire flashlights, or other brands of incandescent (halogen, kyrton, xenon, etc) flashlights which have a bulb rated 7.2V and under.
We typically do NOT recommend these for any bulb flashlights - use them at your own risk in these types of devices.
Despite the voltage regulation at it takes the voltage regulation ~12 milliseconds to activate. The batteries will charge to 4.2 Volts before being regulated. Inserting the batteries into your device immediately after removing them from the charger could possibly damage your device! *They work GREAT for most LED flashlights!*

Given the description of the description of the circuitry, and the fact that they charge to 4.2V, I'm not clear why I can't charge them on the same charger I can use for 3.7V RCR123s. Anyone have any experience with these?


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## Shadowww (Jan 9, 2013)

Why aren't you considering LiFePO4?

3.7V Li-Ion's with voltage-dropping diodes are generally complete crap.


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## dusty99 (Jan 9, 2013)

Thanks, that helps. I bet I can't use my RCR123 4.2V charger, though....


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## Shadowww (Jan 9, 2013)

You can't, but you can't use normal 4.2V on "3.0V" Li-Ion's either, because they need 4.5V to charge.


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## Changchung (Jan 9, 2013)

I think that the OP is confused about the explanition that he receive from surefire, they toll him that he cant use regular RCR123 because their are so high in voltage 4,20v full charged or fresh this is because he recomend use 3.20volts rechargables, LiFePO4 or similar and those batteries cant be charger in any regular li-ion charger.


Sent from my phone with camera with flash and internet on it...


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## dusty99 (Jan 9, 2013)

No confusion (at least I don't think). I was trying to work around the fact that my Eagletac D25C changes modes a bit and has a stated 5-min. "turbo" limit w/RCR123 3.7V batteries.


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## Changchung (Jan 9, 2013)

dusty99 said:


> I have an Eagletac D25C and like the modes the way they are now, and to not worry about the heat generated with longer runtimes using a RCR123a 3.7V, but I'd like to run rechargeables. Any thoughts about the 3.0V versions? Since the ones I've seen online seem to be 3.7V batteries with internal regulation, can I charge them with my XTAR 4.2V charger?
> 
> Thanks!





dusty99 said:


> No confusion (at least I don't think). I was trying to work around the fact that my Eagletac D25C changes modes a bit and has a stated 5-min. "turbo" limit w/RCR123 3.7V batteries.



Sorry, but I dont see that in any of your past posts, you are asking if you can use rechargables in your light, your light cant run 4,20v rechargables because you can blow the Led or driver or everything, you can use lipo or similar, those rechargables had less voltage than regular rechargables, 3,2v I think that is clear because the others post. That is the answer what you receive from the costumer service or this is what you post before.


Sent from my phone with camera with flash and internet on it...


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## VidPro (Jan 10, 2013)

I use a few of the "regulated" type of 123 li-ion cells, because they can have a tiny bit more total capacity over the li-fe kind at normal discharges.
Because of the voltage slop of the "regulation" , they have to be charged "special" . They can be put on the cheap li-ion charger and terminate , but they do not charge up fully *at all *without the higher voltage designed for a regulated "3.0V" li-ion battery. 

So
basically they shouldnt blow-up or fail on a regular charger , i have done it many times, but you will not get crud for capacity , or you would not charge the internal cell any usefull ammount

The reason you wouldnt use these on a high powered incan light, is because the extra voltage slop is being tossed out as waste right there on the top of the cell, and the regulation probably could not handle amps.


The 4 different things for the 123 battery hole, makes understanding it all a royal pain in the butt. 

Primary
You got the primary, which is what most of the lights are made FOR and by and designed around, it has good capacity and cannot be reused.

Li-Ion
You got a standard "unregulated" li-ion cells which are higher voltages than many of the light designs, and "protected" versions of those. They have fair capacity. Charges on a standard li-ion charger as long as the current of that charger can go low enough. Flashlights that say "Do not use li-ion" rechargable cells will run hotter higher and possibly fail due to the higher voltage (currents via those voltages).

Regulated Li-ion
You got the regulated li-ion , which attempts to simulate a primary voltage, so the lights designed only for primary will not be slammed. The voltage slop makes it very hard to understand. The delay time on the regulation is so quick it is not really an issue. It Wastes some of its power in regulation, the internal cell though (before waste) can have li-ion capacity. On the other side of the regulation, is a li-ion cell. It Will not charge properly with li-ion charger, must have charger designed for (or switched to) regulated cells.

Li-Fe
The Li-Fe type cell, the chemistry of the cell itself is at a lower voltage. Lower total capacity, higher current capability, cannot be charged "properly" on li-ion charger without li-fe type setting.


Between the li-Fe which is a sorta 3v type battery, and the regulated 3v type, the charging on these is TOTALLY different voltage. Which means that somewhere out there is a charger that says 3v and another with a 3v switch , and they are not the same at all. Another fun thing to add to the mess.

I have attempted to explain it all correct in other threads, and it just makes a big huge Mess  Probably it is best to understand them One at a Time. In this situation, the answer is NO, your really going to have to get one, measure , test measure, to really understand it first hand. 

The chargers for the different rechargable styles are completly different in these situations. Charging a li-fe or a li-ion in a charger with the higher voltage for a regulated cell would be disaster. 

Because i only use a few regulated cell items, I just use a bench power supply to charge them manually, that also means less errors putting things on the wrong charger, or switched the wrong way, because i have to set everything for it.


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## dusty99 (Jan 10, 2013)

Thanks for the helpful recap. Just to be clear, the D25C _can_ run on a 3.7V cell according to Eagletac, but supposedly it drops a "medium" mode and there is a warning about no more than 5 min. on turbo. I may just try a regular 3.7V 16340 for awhile and not use turbo.


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## cyclesport (Jan 10, 2013)

dusty99 said:


> Thanks for the helpful recap. Just to be clear, the D25C _can_ run on a 3.7V cell according to Eagletac, but supposedly it drops a "medium" mode and there is a warning about no more than 5 min. on turbo. I may just try a regular 3.7V 16340 for awhile and not use turbo.



The D25C does drop medium mode using 3.7v Li-ion's, goes out of regulation into direct drive, essentially giving you...moonlight/low-turbo-turbo (cycled twice) then disco. So your assumption that you just won't use turbo only leaves you w/moonlight and low and flashing modes. 

The D25C is a very efficient light and (owning two of the XM-L U2 versions), it's one of the few lights in which I don't mind using CR123 primaries. You get such a long run time, especially if you're using mostly the lower modes, that the cost of using primaries is insignificant and you maintain all output modes and thermal regulation. That said, I still use 16340s in these lights most of the time since moonlight and low will take care of most things for which one needs light, and turbo will run plenty long enough w/o damage or too much heat when you need huge amounts of light...but yes it will get quite warm starting at the 30sec mark. This light is more robust than you might imagine after reading ET's scary disclaimers. You just can't run this light for protracted lengths of time on turbo, really not a big deal for EDC duty.


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## dusty99 (Jan 11, 2013)

Thanks, CS. Just to clarify, ET makes it sound like the D25C goes to moon-low-high-high w/ 3.7V then still has a higher "turbo" when the head is tightened all the way. Are you saying that tightening the head doesn't bump up output over the two "highs" w/ loosened head?


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## cyclesport (Jan 11, 2013)

dusty99 said:


> Thanks, CS. Just to clarify, ET makes it sound like the D25C goes to moon-low-high-high w/ 3.7V then still has a higher "turbo" when the head is tightened all the way. Are you saying that tightening the head doesn't bump up output over the two "highs" w/ loosened head?



That's right...tightening the head does nothing to increase output on either one of my D25Cs beyond the (former) Medium-High modes using 16340 li-ions...because at 3.7v, M-H-Turbo are all at max in direct drive.

*Disclaimer: I'm only talking about 2012 D25C lights...ET is currently in the process of updating their drivers starting w/the Ti lights so its possible a 2013 version may behave differently, read: more modes w/16340's.


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## dusty99 (Jan 11, 2013)

Thanks, that's helpful. Mine is a 2012. I think you're correct about this being a pretty cheap light to run on primaries. My thinking was that I have a 1x18650 light and another on the way, and they will both run a bit brighter on 2x16340s, so I would pick up a half dozen of those and be set for multiple lights, but its not a necessity (esp. with CR123s a buck apiece over the internet). I really like the D25C clicky - great modes (the "low modes" option moonlight is perfect), great size for any pocket (I removed the clip), and actually 5-6 grams _lighter_ than my 1xAA T10 or L10 w/batteries.


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## loquutis79 (Mar 25, 2013)

So it would be nice if someone actually answered the actual question.

Can we run the D25C Ti on rechargable li-ion 3.0 volt batteries and maintain all the light levels. I'm pretty sure that was the question. I want to know that also, having just bought the same 2012 version of the light.


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## dusty99 (Mar 25, 2013)

I think the official answer turned out to be "yes" for 3v Li-Ion & 3v LiFePO4, but runtimes will be shorter than with primaries. What I think you're asking about, 3.6 (4.2)v RCR123s, from what EagleTac said, will only maintain all modes with the most recent D25C Ti that has the new driver. Hopefully this will trickle down to the standard aluminum D25Cs in the near future. It's not clear to me when the updated driver was incorporated, so your 2012 Ti may only have the two modes.



loquutis79 said:


> So it would be nice if someone actually answered the actual question.
> 
> Can we run the D25C Ti on rechargable li-ion 3.0 volt batteries and maintain all the light levels. I'm pretty sure that was the question. I want to know that also, having just bought the same 2012 version of the light.


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## Colonel Sanders (Mar 25, 2013)

loquutis79 said:


> So it would be nice if someone actually answered the actual question.
> 
> Can we run the D25C Ti on rechargable li-ion 3.0 volt batteries and maintain all the light levels. I'm pretty sure that was the question. I want to know that also, having just bought the same 2012 version of the light.



It seems to me that the original question was about charging 3.0s rather than if they could be used in the D25c and maintain levels.

"Any thoughts about the 3.0V versions? Since the ones I've seen online seem to be 3.7V batteries with internal regulation, *can I charge them with my XTAR 4.2V charger?*"

And the answer is no, not if you want them to charge properly.


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## loquutis79 (Mar 25, 2013)

Tenergy lists a 3.0 volt li-ion. This is the one I am curious about. Would that not function the same as a 3 volt primary? 
Sorry if I sounded rude.


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## Grmnracing (Mar 25, 2013)

I know people are running the 3.0v with no problems. Unprotected, you better keep an eye on the voltage drop. I believe 2.2v was the number not to drop past. 

The Li-Ion should be protected if memory recalls. 

Steven


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## loquutis79 (Mar 26, 2013)

So what I'm looking for, is there anyone out there using the EXACT battery I am thinking of. Tenergy 3.0 volt li-ion 16340. I don't want to take a chance with "maybes" and "should work" and blow up my brand new light, if you know what I mean.


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## AnAppleSnail (Mar 26, 2013)

It sounds like most people are steering clear of these. It's kind of a kludge-ey fix, using a 0.6v dropping diode to decrease cell voltage. That means the LiCo (3.6v nominal 4.2v peak common li-ion chemistry) cell output ranges from 3.4v fresh to 2.8v super-dead. And requires a special charger. And wastes about 1/5th of the cell's power as heat...right next to the cell. Most people shy away from heating li-ions like that.


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## Colonel Sanders (Mar 26, 2013)

AnAppleSnail said:


> It sounds like most people are steering clear of these. It's kind of a kludge-ey fix, using a 0.6v dropping diode to decrease cell voltage. That means the LiCo (3.6v nominal 4.2v peak common li-ion chemistry) cell output ranges from 3.4v fresh to 2.8v super-dead. And requires a special charger. And wastes about 1/5th of the cell's power as heat...right next to the cell. Most people shy away from heating li-ions like that.



I agree 100%. I have on order a light that strictly uses 3.2v or less (Aeon). It's designed specifically for primaries. If I decide to use rechargeable cells with this light, they will be LiFePO4. That's a very good and safe chemistry with excellent load handling, voltage stability, and life expectancy (number of cycles.)

In my thinking, why screw around with a hack job LiCo when you have the option of LiFePO4?


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## loquutis79 (Mar 27, 2013)

Which isn't protected


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## Colonel Sanders (Mar 27, 2013)

loquutis79 said:


> Which isn't protected



LiFePO4s don't come with protection because they are inherently far safer than LiCo or even IMR cells. I guess the thinking is why add the extra resistance (less efficient), cost, and length if it's not necessary?


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## Dlight (Apr 10, 2013)

So I am researching the exact same topic. I was interested in trying the Tenergy 3.0v RCR123A in my new D25C, but would like something that funtions properly and will not damage the light. So are they ok to use in this light?


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