R17670 (2x123 size) Question

[ltiu]

Did I miss something?

I got a R17670 (2x123 size) so that I won't have to bother with loading 2x 123 into my 2x 123 flashlight.

But then I realized, the R17670 (2x123 size) is actually just 3.7v and not 2x 3.7v = 7.2v which is what you would get with 2x 123.

My question now is:

What's the point of the R17670 (2x123 size)?

Do we actually have flashlights that uses this type of battery and be as bright as 2x 123 even with the voltage cut in half?

Thanks.

 

[Marduke]

There are plenty of flashlights that are happy using that wide voltage range. The point of using it is because it contains much more energy than 2xRCR123's

The Fenix P3D and T1 come to mind.

There are also a number of P60 LED dropins on DX which are designed to take specifically that voltage to run on either 17670 or 18650 cells in place of 2xCR123's or 2xRCR123's

 

[mdocod]

there are a number of 3.7V lamp assemblies on the market for use in common tactical flashlights. Ideally speaking, an 18650 compatible flashlight is much more practical and worthwhile. 30% more runtime than a 17670 and only a hair larger.

 

[ltiu]

Follow-up questions:


1) More energy?

The AW 17670 has:

3.7v x 1600 mAh = 5920 milliwatts

The AW RCR123A has:

3.7v X 2 X 750 mAh = 5550 milliwatts

NOT BY MUCH!


2) Other flashlights?

The 17670 does not fit into my P3D Q5. I tried to get it in and it gets stuck.

 

[ltiu]

there are a number of 3.7V lamp assemblies on the market for use in common tactical flashlights. Ideally speaking, an 18650 compatible flashlight is much more practical and worthwhile. 30% more runtime than a 17670 and only a hair larger.

Sorry, what is a "18650". Is it a 2x CR123 size as well but just a bit longer with the same circumference? Will it fit into a P3D and SureFire 6P?

 

[GRoLED]

An 18650 is a LiIon rechargeable battery, 18mm in dia and 65mm long (so a bit shorter and greater diameter)

The '0' at the end indicates it's round. The same convention holds for 17670's, 18500's, 17500's etc.

Generally the diameter of the 18XX0 means that you struggle to get them into a CR123 based light (as is sometimes the case with 17XX0's) for reference the dims of a CR123 16mm dia x 34mm lg, i.e 16340.

I'm sure there are other reference tables around, but off the top of my head AW's sales thread has a lot of good information to start on battery size:

http://www.cpfmarketplace.com/mp/showthread.php?t=173892

Covers AA, 1/2 AA etc etc.

Hope that helps

(And yes, my L4 for one runs like a charm on my 17670's)

 

[dulridge]

I see Groled types faster than I do..

Sorry, what is a "18650". Is it a 2x CR123 size as well but just a bit longer with the same circumference? Will it fit into a P3D and SureFire 6P?

Nope. The first two digits are the battery diameter, the 3rd and 4th its length. The "0" at the end means it is a cylindrical cell )I think)

So a 17670 cell is 17mm diameter and 67mm long.

An 18650 is shorter and fatter, it is 18mm in diameter and 65mm long.

Many lights designed for 2xCR123 (16340) will take 17670's but will not take 18650 cells (e.g., surefire lights)

My P3D takes a 17670 as a snug fit - as in you can hear air sucking when you shake it out of the light - it is not going to fall out. There is no way an 18650 is ever going to fit in there, an unprotected 17670 only just fits.

The 2mm length difference is not a big deal, most lights will happily cope with that.

I doubt a protected 17670 will fit at all as they are a fraction thicker due to the conductive strip running from the anode to the protection circuit which necessarily makes the cell fatter.

Don't have or want a 6p so no idea but AFAIK no standard Surefire body will accommodate an 18650.

 

[Marduke]

Follow-up questions:


1) More energy?

The AW 17670 has:

3.7v x 1600 mAh = 5920 milliwatts

The AW RCR123A has:

3.7v X 2 X 750 mAh = 5550 milliwatts

NOT BY MUCH!


2) Other flashlights?

The 17670 does not fit into my P3D Q5. I tried to get it in and it gets stuck.

But also one cell is much safer than two, and easier to use.
Also, the P3D is brand dependent for 17670's. Some fit, some won't. For example, for the most part, old AW's won't, but new ones will. It's close enough that the specific wrapper on the cell makes a difference between brands.

 

[ltiu]

But also one cell is much safer than two, and easier to use.
Also, the P3D is brand dependent for 17670's. Some fit, some won't. For example, for the most part, old AW's won't, but new ones will. It's close enough that the specific wrapper on the cell makes a difference between brands.

My new AW 17670 won't fit into my 3 month old P3D Q5. It is tight and it won't slide in on it's own and I am not pushing it in.

 

[Marduke]

My new AW 17670 won't fit into my 3 month old P3D Q5. It is tight and it won't slide in on it's own and I am not pushing it in.

Have you tried putting it in from the other end?

As long as it doesn't tear the wrapper, it doesn't do any harm to push it in gently.

 

[mdocod]

1) More energy?

The AW 17670 has:

3.7v x 1600 mAh = 5920 milliwatts

The AW RCR123A has:

3.7v X 2 X 750 mAh = 5550 milliwatts

NOT BY MUCH!

actually...

https://www.candlepowerforums.com/threads/117117

RCR123s= ~2WH each
17670s= ~6WH each.

17670 has about 50% more WH than 2xRCR123

 

[SilverFox]

Hello Mdocod,

Keep in mind that when you have 2 cells in series the voltage doubles. This also effects the Wh value...

Tom

 

[mdocod]

6wh/4wh = 50% more

 

[SilverFox]

Hello Mdocod,

Oops, what was I thinking... You are correct.

Tom

 

[Fenris]

.

 

[ltiu]

actually...

https://www.candlepowerforums.com/threads/117117

RCR123s= ~2WH each
17670s= ~6WH each.

17670 has about 50% more WH than 2xRCR123

I'm sorry, where in the link did you get the "~6Wh each" and how did you arrive at the 50% value?

I cannot find it there in any of the graphs.


17670 is 3.7v x 1600 mAh = 5920 mWH
RCR123 is 3.7v x 2 x 750 mAh = 5550 mWH


Yes, about 10% more, but not 50% as you mentioned.

 

[merlocka]

I'm sorry, where in the link did you get the "~6Wh each" and how did you arrive at the 50% value?

I cannot find it there in any of the graphs.


17670 is 3.7v x 1600 mAh = 5920 mWH
RCR123 is 3.7v x 2 x 750 mAh = 5550 mWH


Yes, about 10% more, but not 50% as you mentioned.

The thread he posted shows the output curves of various cells vs current draw rate. Depending on the application, and the amount of current the cell has to supply, you can get very different performance from the cells. Using the label value isn't the best way to compare capacities.

If you look at the AW RCR123A (a very common cell here at CPF), you see that for a .5A draw rate, the cell provides ~2Wh, and about 1.3Wh for a 1A draw rate. Other RCR123A's get up to 2Wh at 1A draw rate.

If you look at the Pila 600S (which is comparable to a 17670 cell), you see that for a 1A draw you get 6Wh.

So, if you do the math at 1A, you have 6Wh for a 17670 vs 2 x 1.3Wh = 2.6Wh (at the low end) or 2 x 2Wh = 4Wh (at the high end).

As far as the actual benefits, it all depends on the application. The use of a single 18650 or 17670 in a 2 CR123A LED light is quite popular because although the maximum output may be a bit lower, you often end up with a considerable runtime increase. Many call this effect "guilt-free lumens".

Take a look at this thread for example. It includes some run-time plots which compare output/runtime of CR123 vs RCR123 vs 18650:

https://www.candlepowerforums.com/threads/182724

Let me know if this helps.

 

[mdocod]

thank you for explaining that merlocka

That is exactly right. the 600S is Pilas designation for a 17670 cell.
I compared the 6WH it delivered into a 1A load to the 2WH that the RCR123s are sortof averaging into a 0.5A load. The comparison is fair and valid since a ~7.4V battery of 2xRCR123s delivering 0.5A is the same wattage output as a single 3.7V cell delivering 1A. So by comparing the capacity of the 17670@1A to the [email protected] we can say that a 17670 has 50% more capacity than a pair of RCR123s.

 

[Ace12]

I have been considering getting 17670 rechargable for a while now, for my Argo HP. What Brand do you guys reccomend and where can I buy them?

 

[mdocod]

Ace12, that's an excellent plan, I run my Argo on 17670s almost exclusively. I almost always recommend AW brand cells as they have great capacity and consistency from cell to cell, and also are constructed better than most other protected cells. They are slightly pricier than the "cheap" stuff out there but I am a firm believer that they are the best value. You can get them here:

http://www.cpfmarketplace.com/mp/showthread.php?t=173892