CR123/RCR123 v. 18650; Pro's & Con's?

[Adirondack47]

Good Morning All-

Ive got an SF G2 & 6P that are about to start sporting new R2 lamps(DX SKU.11836) and an E2D which will soon be playing host to an LF 150lm lamp module from LF.

Im wondering what the advantages or disadvantages would be in running cr123/rcr123's vs. running 18650's in these lights?

I already have a mittful of UltraFire protected rcr123's and a DSD2 charger but im also interested in finding out if switching to 18650's would be beneficial for runtime/brightness/throw etc?

I have a rudimentary understanding of voltage/amperage etc but dont really grasp the "whole picture" if you will, when it comes right down to making a black & white comparison of each battery setup.

Any input is, as always, greatly appreciated

 

[ab1ht]

Good question. I asked the same thing in another thread.

As a noob, I don't know much. But I'll tell you what I know; it won't take long...

One benefit of the 18650 is that it's a single cell. If two cells (e.g. 2xCR123) are used together, you have to make sure they are as closely matched as possible in terms of charge. Otherwise, there is the potential for

I look forward to other helpful insights.

 

[Adirondack47]

BTT for the Thursday afternoon crowd

 

[RobertM]

Good Morning All-

Ive got an SF G2 & 6P that are about to start sporting new R2 lamps(DX SKU.11836) and an E2D which will soon be playing host to an LF 150lm lamp module from LF.

Im wondering what the advantages or disadvantages would be in running cr123/rcr123's vs. running 18650's in these lights?

I already have a mittful of UltraFire protected rcr123's and a DSD2 charger but im also interested in finding out if switching to 18650's would be beneficial for runtime/brightness/throw etc?

I have a rudimentary understanding of voltage/amperage etc but dont really grasp the "whole picture" if you will, when it comes right down to making a black & white comparison of each battery setup.

Any input is, as always, greatly appreciated

First up, and most importantly, 18650 cells won't fit in your G2 or 6P. They are too wide (17670 will generally fit though).

Second, 2x RCR123 DO NOT equal 2x CR123 cells. Whenever you use rechargeable Li-ion, be sure the voltage spec of the flashlight/drop-in will work with 3.7v (1x RCR123) or 7.4v (2x RCR123). 2x CR123 are ~4.8-5.5v depending on how hard they are being driven.

Since the drop-in you have from DX says it supports input voltages of 3.7V~18V, you could run any of the following in your G2/6P: 2xCR123, 2xRCR123, 1x17670.

Just as a general comparison, RCR123's will give you rechargeable capabilities, but they have less energy density than CR123 primary cells (reduced runtime). For your DX drop-in, I'd use either 2xCR123 or 1x17670.

-Robert

 

[Adirondack47]

Thank you for the clarification RobertM- much appreciated. Im assuming that I could run my E2D with a single 17670 as well?

Is there a certain brand of 17670's (among those for sale at DX) out there that are highly regarded?

 

[bxstylez]

AW protected rechargeable cells are highly regarded!

ie: AW 17670

.

 

[bxstylez]

in regards to using a single 17670 cell in a E2D.... are you planning to put in lumens factory HO-E1R or EO-E1R lamp assembly in it?

i would drop in 2x AW's IMR-16340 cells (also known as RCR123's, still rechargeable, red wrapping, different/safe chemistry, can be discharged at higher rates at the expense of energy capacity) and run the IMR cells with LF IMR-E2 lamp assembly, for a blinding 350 lumens WOW-light

.

 

[Gatsby]

And you may want to double check if a 17670 will fit in your E2 body ... they fit in my 6PL just fine but the E2s are a lot slimmer...

I admit that I get a little bit nervous with 2xRCR123s - you really do need to be quite careful about matching their charges. I'm thinking of picking up a few LiFePo 3.0v cells for 2 cell applications. But I admit that if I can run an 18650 or 17670 I generally do it.

 

[kramer5150]

Good Morning All-

Ive got an SF G2 & 6P that are about to start sporting new R2 lamps(DX SKU.11836) and an E2D which will soon be playing host to an LF 150lm lamp module from LF.

Im wondering what the advantages or disadvantages would be in running cr123/rcr123's vs. running 18650's in these lights?

I already have a mittful of UltraFire protected rcr123's and a DSD2 charger but im also interested in finding out if switching to 18650's would be beneficial for runtime/brightness/throw etc?

I have a rudimentary understanding of voltage/amperage etc but dont really grasp the "whole picture" if you will, when it comes right down to making a black & white comparison of each battery setup.

Any input is, as always, greatly appreciated

General comments:
It really depends on the light. Very few regulated 2x16340/CR123 lights are equally bright or regulated off an 18650 at 4.2V. There are only 5 that I am aware of, P100C2, T100C2, Lumapower encore and maybe the Fenix TK12 (I have seen conflicting user reports/measurements).

A well designed/regulated 18650 only light can be just as bright as an equally well designed 2x16340.

Pros to a 2xCR123/16340 setup:
-Recharge times are less
-Slightly smaller body size
-Maybe slightly more light models to choose from
-Two different cell chemistries are possible in the same light

Pros to an 18650 setup
-Longer run times with high capacity 18650
-Easier field reloads and easier to manage spent cells (one big versus two small)
-Safer when used at higher drive currents. Don't quote me on this but most if not all reported Lithium explosions are from dual cell lights.