What lights benefit from RCR123 cells

madecov

Flashlight Enthusiast
Joined
Feb 16, 2003
Messages
2,151
Location
Houston, Texas
I own several newer lights and was wondering what lights would benefit from the above listed cells.

I'm leaning towards my Quark X 123^2 tactical XML since 18650 cells don't fit the Quark body.

Other lights I own are the

O-Light M21X
EagleTac T20C2 MKII (XML)
Klarus XT-11 (not recommended to use RCR cells)
Fenix TK-21 (not recommended to use RCR cells)
Klarus XT-2C
Klarus XT-1C
Sunwayman T20-C

I do run all of the above on 18650 batteries by Redilast and AW (except the Quark).
 

shane45_1911

Enlightened
Joined
Apr 28, 2009
Messages
594
Location
Ontario, Canada
Spend some time over in the battery sub-forum. It is generally ill-advised to run 2 x RCR123's in the same light in case one discharges faster than the other to the point of reverse polarity. The danger occurs when you go to recharge to over-discharged one - POOF. Don't rely on a protection circuit for peace of mind.

Also, many lights cannot handle the increased voltage that RCR's put (4.2V, or 8.4V if you are running two) versus the 3V (or 6V with 2) that a primary CR123 battery puts out.

A single 18650 as you mentioned (or 17670) is much safer to use. YMMV.
 

Jrubin

Newly Enlightened
Joined
Sep 29, 2011
Messages
134
Location
Alaska
Spend some time over in the battery sub-forum. It is generally ill-advised to run 2 x RCR123's in the same light in case one discharges faster than the other to the point of reverse polarity. The danger occurs when you go to recharge to over-discharged one - POOF. Don't rely on a protection circuit for peace of mind.

Also, many lights cannot handle the increased voltage that RCR's put (4.2V, or 8.4V if you are running two) versus the 3V (or 6V with 2) that a primary CR123 battery puts out.

A single 18650 as you mentioned (or 17670) is much safer to use. YMMV.

That is great info,I should have known about two rcr's being an issue...hmm I guess it's 17670 for me now
 

jjohnson34

Newly Enlightened
Joined
Nov 5, 2011
Messages
101
I've used the same set of RCR123's in my Surefire 6P for 8+ years now. No problems ever. Still work perfect. Lenmar brand. Bought at batteries plus 8 or so years ago
 

ico

Enlightened
Joined
Aug 1, 2011
Messages
554
Location
Philippines
The danger occurs when you go to recharge to over-discharged one - POOF. Don't rely on a protection circuit for peace of mind.

By "POOF", do you mean the battery dies or an explosion might occur?
I'm planning on using 2 RCR's in my quark turbo X 123² since it can handle up to 9v. Most say they use a 17670 on theirs but 4sevens does not recommend on using a 17670. Only 2 primaries or 2xRCR123's.
 

shane45_1911

Enlightened
Joined
Apr 28, 2009
Messages
594
Location
Ontario, Canada
By "POOF", do you mean the battery dies or an explosion might occur?
I'm planning on using 2 RCR's in my quark turbo X 123² since it can handle up to 9v. Most say they use a 17670 on theirs but 4sevens does not recommend on using a 17670. Only 2 primaries or 2xRCR123's.

When you recharge a battery that has been over-discharged, it may indeed explode or "vent with flame".

I don't have time to look at 4Sevens site right now, but do they really recommend using 2 RCR123's? If so, now I have ANOTHER reason to avoid their products. (Unless they mean IMR 123's? Li-Ion batteries should not be used in pairs IMO, except for very limited runtimes. The risk is not worth it.)

The ONLY reason for not using a 17670 is if you need greater than 4.2V for full brightness. Using 2 primaries (2 x 3V = 6V) is a better option if you need more voltage, but a 17670 will work just fine in any light that uses 2 primary CR123 cells.
 
Last edited:

shane45_1911

Enlightened
Joined
Apr 28, 2009
Messages
594
Location
Ontario, Canada
The only reason that 17670 cells are not supported is because they may not provide enough voltage (4.2V) to give max brightness in whatever light we are talking about. There is nothing unsafe or dangerous about using a 17670 instead of 2 CR123s - just lower voltage.

And I still strongly disagree with their recommendation of using 2 RCR123s. You cannot control discharge rates and 2 cells rarely have the same starting capacity. One will discharge faster than the other, and if you reach the point where one still has capacity and the other one is exhausted, you WILL over-discharge the spent one. And bad things will happen when you try to recharge it. POOF.
 

shane45_1911

Enlightened
Joined
Apr 28, 2009
Messages
594
Location
Ontario, Canada
Don't a lot of lights use multiple Li-io cells though? Such as multiple 18650's and the like. Is it really that risky?

Depends what chemistry we are talking about. IMR rechargeables are safer to use in pairs. Li-Ion, not so much.

Again, the danger is not so much in using them (especially if you keep your runtimes under the capacity of the batteries themselves). The danger is in recharging - especially if you are not sure how far you have drained the batteries. Protection circuits SHOULD work to prevent overdischarge, but I don't rely on them to prevent reverse polarity/over-discharge. If you try to recharge a battery that was drained to the point of reverse polarity, bad things may happen.

YMMV. IMO. Etc. etc.
 

Chicken Drumstick

Flashlight Enthusiast
Joined
Dec 9, 2011
Messages
1,651
Location
UK
shane, thanks for the info. As you've probably guessed I'm quite new to this, so sorry about all the questions.

Just so I can get it clear in my head. The review of the TM11 looks liked it used a Redilast Protected 18650 as that is what it is photographed with. I believe these are ICR's not IMR's? The review also doesn't seem to mention that you need IMR cells specifically.

So I thought I'd look at the Nitecore web site and found this:

http://nitecore.com/images/201109/TM11.pdf

Where it says:

"Do not use lithium batteries without a protected circuit board.

This product does not support 18650 rechargeable Li-ion
batteries without protection circuit board as the battery length will
be too short to be used."


Which seems clear enough, however I then looked at these: http://www.ledfiretorches.co.uk/aw-imr-18650-rechargeable-safe-chemistry-batteries.html

Where it says:

"AW IMR 18650 rechargeable battery x 1. Safe chemistry means no risk of venting with flame or explosion. Ideal for use in multiple cell applications

Please note that due to their inherant safety, AW IMR cells don't have a protection circuit built in. "



So my question is:

1. Can you Protected IMR cells?
2. If not, then it would seem the Flashlight sellers/makers are forcing and recommending you use Protected ICR's.


Thanks again.
 

shane45_1911

Enlightened
Joined
Apr 28, 2009
Messages
594
Location
Ontario, Canada
LOL, no worries with the questions - that's how we learn...myself included.

To answer your last 2 questions...

1) No, IMR cells do not need any protection circuitry - they are inherently safer by nature of their chemical composition.
2) You have stumbled upon the "one size does NOT fit all" battery sizing anomoly. A protection curcuit does indeed add length to any given battery and may be too long in some applications. The reverse is also true that a battery without protection may be too short. Not all 18650s are the same length.

I would suggest heading over to the battery sub-forum and read and read and read and then ask more questions and read and read and read again. Good folks there are more knowledgeable than I am about batteries and can probably answer any question you may have - and make you think of a hundred more. Have fun!
 
Last edited:

rambo180

Enlightened
Joined
Apr 1, 2012
Messages
374
Location
Australia
LOL, no worries with the questions - that's how we learn...myself included.

To answer your last 2 questions...

1) No, IMR cells do not need any protection curcuitry - they are inherently safer by nature of their chemical composition.
2) You have stumbled upon the "one size does NOT fit all" battery sizing anomoly. A protection curcuit does indeed add length to any given battery and may be too long in some applications. The reverse is also true that a battery without protection may be too short. Not all 18650s are the same length.

I would suggest heading over to the battery sub-forum and read and read and read and then ask more questions and read and read and read again. Good folks there are more knowledgeable than I am about batteries and can probably answer any question you may have - and make you think of a hundred more. Have fun!

sorry to take the focus off batteries. would you say the m21x and the xt11 have comparable throw, or if the m21x wins, does the xt11 still have good throw for an 18650? thankyou!!
 

TEEJ

Flashaholic
Joined
Jan 12, 2012
Messages
7,490
Location
NJ
sorry to take the focus off batteries. would you say the m21x and the xt11 have comparable throw, or if the m21x wins, does the xt11 still have good throw for an 18650? thankyou!!

The XT11 is not as throwy as the M21X. The XT11 has a strong floody beam, the M21X has a tighter beam.

The XT11 drops to 70% on drop down, the M21X drops to 60%, but the XT11's 600 lumens is based upon using an 18650, and the M21X is based on using 2 123's...

AT PF18 we measured the XT11 with two RCR123's as pumping out 850 lumens.

:D
 
Top