RCRs the same size as CR123As

[Beacon of Light]

I went to a gun show over the weekend and bought a laser for my gun that uses 2 CR123As and I intended to use the Ultrafire RCR123 880mAhs that I bought specifically for my Novatac EDC85 that didn't work, and everything would be good. I stuck the cells in the laser and they were so snug I had a slight heart attack when they didn't come out. So my request is what are RCRs that have the same diameter of CR123s? I had no idea there wasn't a standard in regards to general battery size with CR123a and RCR123s.

I never wanted to get into CR123/RCR123s from the get go and now I am seeing the exact reason why I avoided it like the plague. I haven't even gotten to the 3.0v - 3.6 volt discrepancy yet even.

 

[ampdude]

The AW IMR16340 cells are the same diameter as standard CR123a's.

The protection circuit on the RCR cells is usually what makes them fatter in diameter and too snug for certain lights/lasers. The IMR cells don't require a protection circuit.

 

[Armed_Forces]

I'm amazed that you have been hear for 5 friggin' years/900+ posts and are just now finding this out???

..don't even get me started on that username!


Here's another shocker:
You better make sure that laser can handle 8.4 volts because Li-Ion and lithium primaries are different voltages!

 

[Beacon of Light]

Yeah I have been here for 5 years but only until a month ago I decided to venture into CR123 cells. Probably my biggest regret since there isn't a standard in regards to size/diameter. 8.4 volts? 2 3v cells would be 6v, where are you getting 8.4 volts? Even the 3.6v cells would be 7.2 volts. Unless there is some x factor I don't see how even that would go from 7.2 to 8.4 volts. Edumacate me please.

 

[HKJ]

8.4 volts? 2 3v cells would be 6v, where are you getting 8.4 volts? Even the 3.6v cells would be 7.2 volts. Unless there is some x factor I don't see how even that would go from 7.2 to 8.4 volts. Edumacate me please.

LiIon is 4.2 volt fresh of the charger, when they get loaded the voltage will drop, how much depends on the load and the charge condition.
They are marked 3.6 or 3.7 volt because that is a good estimate of the average working voltage.

 

[Armed_Forces]

I know all this battery stuff can be confusing but having the ability to use rechargeables is worth a little pain with the learning curve in my opinion.


When you see a voltage listed for a battery that is what's referred to as its "nominal value". The voltage of the cell when fully charged will always be higher than this and it all depends on the chemistry of the cell. Without going overboard with all this an RCR123 hot off the charger is 4.2 volts. x2= 8.4 volts.

Most consumer electronics are designed to operate within a fairly narrow voltage range based on the battery/ies to be used. The user manual will usually tell you whether or not you can use rechargeables. Sometimes it gives you a range of input voltage in the specs where you can get a rough idea if nothing is mentioned in the manual. Failing that there's always the try it/hope & pray method. :laughing:

..or give the manufacturer a call.


Best of luck on this!

 

[Beacon of Light]

The manual states CR123As. It doesn't say NOT to use RCRs, so I am assuming they are behind the times and don't even realize people will want/need to use RCRs. Hell they don't even state the nominal voltage not to exceed and I am only going by the supplied batteries it came with, which were Panasonic CR123A 3.0v primaries.

I had to pull teeth to find a laser that worked off of CR123s even as most were button cell/watch battery types and I'll be damned to have to use primary cells on any electronic device in this day and age.

 

[Beacon of Light]

Ok so if a 3.6v off the charger is 4.2v, is there a way to run a 2xCR123 type device with 1xCR123 cell and a dummy cell at the 4.2v and still expect it to work?

 

[HKJ]

Ok so if a 3.6v off the charger is 4.2v, is there a way to run a 2xCR123 type device with 1xCR123 cell and a dummy cell at the 4.2v and still expect it to work?

That depends on the device, some might work, some will not.

But there are a few other LiIon battery options:
LiFePO4 is only 3.2 volt (3.6 volt of the charger)
Regulated LiIon is also closer to 3 volt, but might have a peak at turn on.

Both types requires a dedicated charger, not a regular LiIon charger.

 

[Beacon of Light]

The AW IMR16340 cells are the same diameter as standard CR123a's.

The protection circuit on the RCR cells is usually what makes them fatter in diameter and too snug for certain lights/lasers. The IMR cells don't require a protection circuit.

So that makes these unprotected then?

 

[Beacon of Light]

So since the manual doesn't state I cannot use RCRs would one assume it will go poof if I do?

 

[Beacon of Light]

The other question is can I rundown the freshly charged batteries in a device that can work with the higher voltage until it drops down to the nominal voltage so then it is within the narrow spec needed to use in another device (laser) safely? Can the voltage be checked with a regular voltmeter?

 

[Ragiska]

The other question is can I rundown the freshly charged batteries in a device that can work with the higher voltage until it drops down to the nominal voltage so then it is within the narrow spec needed to use in another device (laser) safely? Can the voltage be checked with a regular voltmeter?

sure, if you want it to explode on recharge after being drained that low.

 

[Beacon of Light]

sure, if you want it to explode on recharge after being drained that low.

ok that sounds dangerous. I thought if I understand correctly, that a 3.7v cell will charge up to 4.2 hot off the charger. My Novatac can use this cell at this voltage safely. I also understood that quickly after being used under a load, that 4.2v cell will drop rapidly to the nominal 3.7v and stay fairly flat at that voltage until it drops and then needing recharging.

I did state I was using protected cells so I thought that was the purpose of avoiding any kind of explosion.

 

[Ragiska]

low loads will often bypass the protection circuit and it will not engage. operating in a moon mode can easily drain a cell far below safe levels. the protection circuit is designed to trigger under load, and then the voltage rebounds to safe levels. when drained under low load, there is no voltage rebound. the protection circuit can do nothing to protect you from charging an overdischarged cell, and a cheap charger will not sense the problem and charge it at too high of an initial current and it will explode.

 

[Beacon of Light]

I think you're missing my point here. I am saying I'd use the hot off the charger 4.2v battery in my Novatacs just for a few hours or whatever it took to get them down to 3.6/3.7v (after checking them on my DMM) and THEN use them in my laser. What's wrong with that?

 

[Ragiska]

I think you're missing my point here. I am saying I'd use the hot off the charger 4.2v battery in my Novatacs just for a few hours or whatever it took to get them down to 3.6/3.7v (after checking them on my DMM) and THEN use them in my laser. What's wrong with that?

3.6v open circuit is DEAD. further use in your laser will take them BEYOND DEAD, and subsequent charging could easily result in your battery doing what is called "rapid disassembly"

 

[Beacon of Light]

3.6v is dead? What am I missing here? 3.6 is what they are rated to run at nominally for most of their charge life and you are saying at 3.6v they are dead and risk blowing up if recharging them if they drop to 3.6v? I read if it's like 2.2 volts or lower then it may be way too discharged to be used again.

 

[Beacon of Light]

Also this thread is getting a bit off topic, my main concern is getting RCRs to FIT this laser at the moment. Which RCRs will fit and be 3.0v and will work with my Ultrafire WF-138 charger (Tenergy RCR900mAh and RCR750 state to ONLY USE THEIR CHARGER ) and will be able to work togetherr in series (another issue I read in which some RCRs in series can trip the protection circuit as it will see the 2xRCR123s as only 1 battery and short circuit). Thanks.

 

[Popsiclestix]

I believe AW's protected 16340 fits anywhere a CR123 will (as well as the IMR).

The battery industry has decided to label primaries @ their open-circuit voltage while labeling rechargables at their nominal (read: working) voltage, leading to ridiculous confusion.

CR123 are labeled at their open-circuit voltage of 3V. They typically sag to 2.5V under load after a few minutes.

RCR123 are labeled at their working voltage. They have an open-circuit voltage of 4.2V and typically sag to 3.7V after a few minutes.

2x CR123 = 6V open-circuit. 5V in typical load application.

2x RCR123 @ = 8.4V open-circuit. 7.2V in typical load application. 6V is dead. Very dead.

From what I can tell, you don't have much choice except to pop in those batteries and see if they'll fry your laser or not.