# CR123A and rechargeable substitutes



## HKJ (Jul 26, 2013)

[size=+3]CR123A and rechargeable substitutes[/size]







This article will be looking at CR123 batteries and some recharge batteries that are supposed to be replacements for CR123 batteries.

The CR123 battery was made for use in cameras, where the high current capacity was very useful for the flash and for the motor drive (Back in the film days). Surefire did like the battery size and introduced it in flashlights (Around 1988). This made small and bright flashlights possible.



[size=+2]Naming[/size]

The correct name is CR123A and this name might be because it is 2/3 of the A battery size (The A battery is not used anymore). Often the battery is only called CR123, sometimes only 123 or 123A. 
Rechargeable batteries that has about the same size is often called RCR123 or R123, this naming is done to signal that they can replace a CR123 (That is not always the case). Another name for that size batteries is 16340, first two digits is diameter and last 3 digits is length in 1/10mm (The diameter will often be 0.5mm more than the number specify, the length can be a couple of mm more). 17335 or 17345 can also be used for this size battery.

The 18350 battery is not really a replacement for CR123, it has to large a diameter, but when working with flashlights a few are large enough to fit a 18350. The 1 mm length difference (xx340 to xx350) will seldom be significant.



[size=+2]Performance comparison to other primary batteries[/size]

Lets compare performance of this battery to ordinary alkaline AA batteries:









To get roughly the same voltage, two AA cells are needed.
The size of CR123 is about 16.5 mm in diameter and 34 mm in length, the AA is 14 mm in diameter and 50 mm in length and a CR123 weight less than a single AA battery.

How does these batteries compare, when drawing power:






At 1A the CR123 has higher voltage (most of the time) and more capacity, making it much better for a high power flashlight than a couple of Alkaline AA batteries.

But the CR123 battery does not always win against Alkaline, at lower loads Alkaline AA has more capacity, but cannot match the voltage of CR123.






The CR123 cannot match the capacity of *two* AA, when using more modern AA batteries (Lithium and NiMH):

















The conclusion of the above curves must be that CR123 can easily match two Alkaline AA batteries, when used in a high power flashlight, but needs much less space. When Using more modern battery chemistries, the advantage of CR123 is more the size and voltage, not as much energy or power.



[size=+2]RCR123 and 16340[/size]

Making a rechargeable CR123 is just about impossible, none of the common battery chemistries has the same voltage. There are a couple of ways to handle that, none of them ideal, i.e. a RCR123 battery is *NEVER* a direct replacement, but will often work.

The 3 common ways to make a RCR123/16340 battery is:


Use a normal LiIon battery with LiCoO2 (ICR) or LiMn (IMR) chemistry in 16340 size, preferable with a protection circuit (This might make the battery to long). This battery will have 4.2 volt fresh of the charger and will be empty when the voltage is down to about 3 volt. This voltage does not match very well with CR123 that has a maximum voltage of 3.2 volt and is below 3 volt when loaded.
Use a normal LiIon battery in 16340 size, but add a diode in series with the battery. This will reduce the output voltage with about 0.6 to 0.7 volt. The voltage will be close to CR123, but still too high and the diode will heat the battery at high loads.
Use LiFePO4 (IFR) chemistry, this chemistry has a lower voltage than normal LiIon, but also less capacity. It does also survive over discharge better, i.e. protection circuit is not that important.

All of the 3 battery types above, does have different charger requirements:


These batteries can be charger on any regular LiIon charger, i.e. 4.2 volt max. and 3.6 or 3.7 volt nominal.
Due to the diode, the charger must supply higher voltage to get full capacity, but they can be charger with a regular LiIon charger.
This chemistry requires a 3.6 volt max. charger, they are usual marked 3 or 3.2 volt.

With led flashlights there is also another "problem", the led needs between 3 and 3.7 volt. A flashlight designed for a single CR123 needs a control circuit that can increase voltage (boost), this means that any battery with more than that voltage will prevent the boost regulator from regulating. Flashlights designed for this usual list two different lumen values, one for CR123 and one for LiIon. When the boost regulator is bypassed, due to the battery voltage, the current will depend on the actual battery voltage, this can overheat the led, especially with a new and good battery. To avoid this, only run the light a few second at full power, when using a recently charged 4.2 volt battery.
Some lights has a buck/boost regulator, i.e. they can both increase and decrease battery voltage, in this case there will not be any heat problems.



[size=+1]ICR (LiCoO2) and IMR (LiMn)[/size]






The voltage from this chemistry is way above the voltage from CR123, i.e. do not use these batteries, except on equipment designed for this higher voltage. Protected batteries are often longer than CR123, but there are exceptions (Like AW). The 18350 has a larger diameter.

The capacity is much lower than the CR123, even the 18350 battery has lower capacity (But more energy, due to the higher voltage).

When using these batteries in CR123 flashlight the brightness will usual be higher and the runtime even shorter than the lower capacity suggest.


















[size=+1]ICR (LiCoO2) with diode[/size]






I have only included one battery in this category, I could not find others, probably due to wrong specifications.
Soshine does also have wrong specifications: It says charge voltage is 3.6 volt, where it must be higher to get full capacity. I did my test with 4.2 volt charger voltage (3.6 volt nominal) and this means that I did not get the full capacity or *voltage*.

This battery is without protection, this makes the size very close to the CR123 size, but it is a problem if the battery is discharged completely.

With the low charge voltage the battery is a fairly good replacement for a CR123 battery, but with much lower capacity.


















[size=+1]IFR (LiFePO4)[/size]






IFR batteries has around 3.2 volt, and lower capacity than ICR batteries. These batteries will be around 3.2 volt, even when loaded, where CR123 drops below 3 volt.

These batteries is without protection and the size is very close to a CR123 battery.

Notice that the Ultrafire battery is marked ICR, but it is a IFR battery.


















[size=+2]Substitutes for multiple CR123[/size]

For lights using multiple CR123, the obvious substitute would be more RCR123 batteries, but that is usual a bad idea. To avoid over discharge and reverse charge, the batteries *must* be protected, this means ICR batteries with up to 4.2 volt. I.e. the voltage will be significantly higher (Check the specifications for the light, if it is allowed).
There are some other substitutes that can sometimes be used:



[size=+1]Two CR123 in series[/size]






The length of two CR123 is close to a xx650 battery with protection. The xx650 battery has considerable lower voltage than two CR123 batteries, but many lights will work with it, often with a slightly reduced brightness (this gives longer runtime). Because the voltage of the LiIon battery is lower, it is always safe to do a test.






The 16650 battery is usual the best choice, except if the light has a large diameter tube, then the 18650 is much better.









[size=+1]3. CR123 in series[/size]






The length of two xx500 batteries is very close to 3xCR123.






As can be seen on the curves the voltage are also very close, i.e. as long as the batteries fit, it will work.






Two xx500 batteries cannot match 3xCR123 in capacity or energy, but are not that far behind.



[size=+2]Conclusion[/size]

There is no easy solution for rechargeable CR123, in each case it is necessary to investigate the equipment for what types can be used.


1 CR123: The solution with most capacity is protected ICR 16340 batteries and the easiest solution is IFR batteries.
2 CR123: If possible use a xx650 battery, alternate possibility is 2x protected ICR 16340.
3 CR123: If possible use 2x xx500 batteries, alternate possibility is 3x protected ICR 16340.

In all of the above cases there can be size and voltage issues.



[size=+2]Battery reviews[/size]

[size=+1]AA rechargeable[/size]
Eneloop AA HR-3UTGB 1900mAh (White)
Eneloop AA HR-3UWXB 2450mAh (Black)

[size=+1]ICR[/size]
Xtar 18350 900mAh (Black)
AW 16340 ICR123 750mAh (Black)
TrustFire TF16340 880mAh (Flame)
Efest IMR16340 V2 550mAh (red)


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## LightWalker (Jul 26, 2013)

A very interesting review, thanks for posting.


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## archimedes (Jul 26, 2013)

HKJ said:


> ....first two digits is diameter and last 3 digits is length in 1/10mm (The diameter will often be 0.5mm more than the number specify, the length can be a couple of mm more)....



This always cracks me up ... specified to the tenth of a millimeter "plus or minus a couple of mm" 

I have also seen some references state that the final "0" indicates a round cell 

Nice review, with rather useful information and graphs / charts.


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## carrot (Jul 26, 2013)

A fantastic overview. Thanks for all your hard work.


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## HKJ (Jul 26, 2013)

archimedes said:


> This always cracks me up ... specified to the tenth of a millimeter "plus or minus a couple of mm"



The problem is the protection circuit and the added button top, the bare cell will be within a few 1/10 of millimetre.




archimedes said:


> I have also seen some references state that the final "0" indicates a round cell




They have not checked the standard (I believe it is IEC), they says R is for round and the 3 digits is the lengths.


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## archimedes (Jul 26, 2013)

HKJ said:


> The problem is the protection circuit and the added button top, the bare cell will be within a few 1/10 of millimetre.
> 
> They have not checked the standard (I believe it is IEC), they says R is for round and the 3 digits is the lengths.



Yeah, I realize that the protection circuit is what adds to the size, but it still strikes me as odd ... when the final dimension is what's sorta important in making sure these batteries actually _fit_ into a device 

I have found even unprotected cells can vary significantly from the "standard".

Yes, IEC uses "R" to denote round cell (IEC 60086-1, 60086-3).


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## HKJ (Jul 26, 2013)

archimedes said:


> I have found even unprotected cells can vary significantly from the "standard".



Button top? The top is often added later and will add length to the cell.


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## archimedes (Jul 26, 2013)

HKJ said:


> Button top? The top is often added later and will add length to the cell.



Sure ... and labels, wrappers, stickers, etc, etc.

I realize that battery manufacturers are more interested in the internal cell, but my point was just that end users (and those who design devices powered by batteries), might appreciate more precise _external_ size information and/or standardization.

I guess that is what springs are for ...


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## WilsonCQB1911 (Jul 26, 2013)

Really appreciate this write up.


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## tobrien (Jul 26, 2013)

great work as usual!


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## reppans (Jul 26, 2013)

Love your batt tests HKJ... Thanks. 

Wondering if you have ever tested a TI 3V lithium primary CRAA/14505. Between this cell and 14500s (which you have shown to have greater capacity than 16340s), it seems the current trend toward broad voltage AA/14500 lights could be the best of both worlds. 

(Unfortunately, the supply of AA-sized 3v and 1.7v Lithium Primaries is extremely captive and limited.)


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## HKJ (Jul 27, 2013)

reppans said:


> Wondering if you have ever tested a TI 3V lithium primary CRAA/14505.



No and it is difficult for me to get lithium batteries from the US


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## jasonck08 (Jul 27, 2013)

I remember a while ago I was given some RCR123 with diodes to test. It came with a charger that put out about 4.5v.

I think that soshine cell is designed to be charged at this high voltage so the diode will drop the voltage to around 4.2v.


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## HKJ (Jul 27, 2013)

jasonck08 said:


> I remember a while ago I was given some RCR123 with diodes to test. It came with a charger that put out about 4.5v.
> 
> I think that soshine cell is designed to be charged at this high voltage so the diode will drop the voltage to around 4.2v.



I agree, but as long as it is sold without any special charger and Soshine write 3.6 volt on their website, I will not test it at higher charge voltage.


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## light-wolff (Jul 27, 2013)

Been testing some RCR123 myself, including the dreaded LiCoO2+Diode cells.
I even ripped some apart to look what's inside and was surprised to even find an integrated circuit that seems to do some kind or overcharge protection by shunting current across the cell.
These "diode cells" are charged via a Schottky diode, and discharged via 1-3 parallel standard diodes.
That is, to charge the cell inside up to 4.2V, you have to apply 4.5V to the assembly because of the Schottky's forward voltage.

On the quest for good 3.2V RCR123A last year I purchased about everthing I could get on ebay and from FT. Some were LiFePO4 (ok), some werde "diode crippled LiCoO2" (not ok).

I soon refrained from testing diode cells because IMO they are good for nothing due to their poor performance under load. I still have 2 of these Soshines sitting in a drawer in their original wrapping, untested.
Adding to this, in none of the places where these batteries are offered did I find any useful information on how to charge them. Most shops offer these batteries without telling the customer what kind of charger to use, and don't even sell the required special charger.
What's the point in selling rechargeable batteries without any idea of how to charge them?

OTOH, I like LiFePO4 RCR123A. They can deliver 3A easily.
Only problem is to find good ones and not get diode cells.
I have some LiFePO4 discharge diagrams in my album in the German flashlight forum (taschenlampen-forum.de). (I hope the album link is ok, couldn't find info yet on CPF policy in this regard.)


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## HKJ (Jul 27, 2013)

light-wolff;4251783That is said:


> I would expect 4.4 volt, a low voltage Schottky diode has about 0.2 volt in drop.


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## candle lamp (Aug 21, 2013)

Thanks for the excellent test review. HKJ! Your reviews are very informative and helpful as usual. :thumbsup:


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## Tetsujin 140.6 (Oct 31, 2013)

Great post. Exactly the information I was looking for! Thanks.

Edit to Add:


Just made the following purchases to see what I can learn about the subject myself.


AW 750mAh 16340 (RCR123A) 3.7V Li-ion Battery with IC Protection
XTAR LIR123A 600mAh 16340 (RCR123A) 3.6V Li-ion Battery with IC
XTAR WP2s Li-ion Battery Charger with USB Output + Car Adapter


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## tripplec (Nov 9, 2013)

I am reading this with great interest in the quest to find a good safe(protected) RCR123 for the new Foursevens "ATOM AL" flashlight for use with the head kit. So far I have drawn a blank on chargers and batteries. I expect this is largely due to the rash differences in the batteries. RCR123 are nearly all different and without a viable standard. This makes me wonder if it is a go cell for the manufacture to even use or support for their lights. With all the battery types out there why even base a design on the CR123 knowing the avid user will look for a rechargeable equivalent. Foursevens I am told designed these ATOM's for higher voltage support but getting the best cell is a problem. Also the Non rechargeable cell is nearly twice the mA capacity of the rechargeable version. Runtime is hence compromised. I am shaking my head. Maybe I need straightening out. LOL


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## ChrisGarrett (Nov 9, 2013)

Volts are higher, capacity is less, but my SunWayMan V11R goes from 210LM up to 500LM on a Li-Ion RCR123/16340 and that's a big jump.

I don't know what you're paying for quality Panasonic CR123As up in Canada, but you can buy AW Li-Co and AW Li-Mn 16340 cells here in the States for $8 a piece and they'll last at least a couple/few years and hundreds of charges. 

If you're going to be somewhere where you'll be using the light a lot, get a little plastic battery case (size of a small Altoids tin) and buy a couple of spares. If you're just casually using the light, like I do when I'm out and about on the town, it's no problem.

If your light is a high current light (2A+,) like my V11R, get the red AW IMR 16340s.

Chris


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## tripplec (Nov 9, 2013)

No idea what if would or could draw. There are only two brightness settings and 110LM is max. http://www.foursevens.com/products/AL-AE Anyway I was not aware a 16450 was size etc compatible with the CR123 or RCR123. My son expect to use it daily in the HVAC trade so rechargeable batterys are a must the SPARK SD52-CW is so so expensive. wow


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## ChrisGarrett (Nov 9, 2013)

tripplec said:


> No idea what if would or could draw. There are only two brightness settings and 110LM is max. http://www.foursevens.com/products/AL-AE Anyway I was not aware a 16450 was size etc compatible with the CR123 or RCR123. My son expect to use it daily in the HVAC trade so rechargeable batterys are a must the SPARK SD52-CW is so so expensive. wow



You can always take a DMM and put the positive lead on the top edge of the flashlight body and put the negative lead on the negative terminal of the battery, pressing down, so contact is made. You might have to lift up on one of the leads, to get the light to cycle through the various modes, if it's a multi-mode light.

Your meter would be set to read DC current (20A?) and you don't want to leave it on there for more than a few seconds.

This way, you can get an idea of current draw on the various modes. If you do this on a glass table top, you can see the brightness of each mode and get an idea of what mode you're measuring.

In your case, with 110LM max, you might get away with the AW Li-Co black 16340 cells.

RCR123 3.7v equals 16340 3.7v. Both descriptors are correct. There are 3.0v LiPo cells, that are the same size, so you need to me mindful of what's what.

Chris


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## tripplec (Nov 10, 2013)

Neither the ATOM AL or Spark SD52 have been purchased yet. The manufacturer does not indicate the draw. But based on the run time of the CR123 its certainly not very good, hence the current must be high on the Max setting. The low being 6LM it would not be used that much. Too low for most applications.


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## MarkRF (Sep 5, 2014)

HKJ said:


> [SIZE=+3]CR123A and rechargeable substitutes
> [/SIZE]
> [SIZE=+2]Conclusion[/SIZE]
> 
> ...


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## HKJ (Sep 5, 2014)

MarkRF said:


> Would the Panasonic Lithium CR123, which I currently use, be the best choice?
> Would I do better (brighter, longer lasting) with a 16340?
> If a 16340 would best fill my need, it looks like the AW 16340 ICR123 (black) is at the top lot the queue (but maybe I've misread your charts and remarks) with a possible nod to the (red).
> 
> I'd love a simple response - and if you think a rechargeable battery is the way to go, please be specific and also recommend a charger.



The list do support using 16340 batteries, this means you do not have to worry about what type batteries to use, it will work with all of them.

The CR123 contains most energy (Wh), this means it can deliver more light (Looking both at brightness and time) than a 16340 battery.
The way these lights are constructed usual means that they will be brighter with a 16340 battery, but when using this you will get a fairly short runtime.
The AW is a good 16340 battery, it has the same size as a CR123 battery and it is good quality, but it does not have the best capacity of the 16340 batteries (Keeppower has one that is slightly better).




MarkRF said:


> Assume money isn't really an issue and I don't use it heavily. I also rarely use it at full power - and when I do, it's usually for less than a minute.



With that description I would assume that more brightness is not very important and with low usage I would say stay with CR123 batteries.
If you decide to try 16340, a cheap charger is Xtar MC0, a very good charger is Xtar SP1 or Xtar XP4c and a "Top of the line" charger Xtar VP2. Because it is small batteries I will not recommend the Nitecore i4 charger.


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## ChrisGarrett (Sep 5, 2014)

MarkRF said:


> HKJ said:
> 
> 
> > I'm seeking the answer to (what I thought is) a simple question: What is the best battery for the new JetBeam RRT01-XML2?
> ...


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## N8N (Sep 5, 2014)

RRT-01 according to the datasheet is listed for use with either CR123A or RCR123A so those are the obvious two choices. I use Surefire for primaries simply because they're inexpensive and available locally; I have AWs for my Li-Ions using a Nitecore i4 V2 charger. I do have some LiFePO4s and a charger (Surefire = K2 Energy) but there is no advantage to using them in a RRT-01 if it can be fed RCRs. I only have them because my Streamlight Night Com UV doesn't play nice with RCRs and I only use primaries for backup cells.


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## xevious (Jul 23, 2019)

*DELETE*

DELETE


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