Use AA, CR123, RCR, and more in one light with simple mod

With all the recent performance increases that have become available to us in the realm of LED flashlights, I thought I would share something I have made up.

I'm not sure if this has been done before.
I'm a fan of AA batteries (alkaline, Nimh, lithium) whatever the chemistry, but I also like my CR123 flashlights.
I guess I have a fascination with using whatever you have on hand to do the job you need done.
Where I live AA batteries rule and are easily the most readily available type of cells.
I always buy my CR123's online and have them shipped from the US.
Why just the other day I saw a well known retailer selling clamshell packets of Duracell CR123's(2x) for AU$35. What a joke!!

I know that I can easily scrounge AA's new or used wherever I may be.
This is certainly the same reason why I first purchased a Malkoff M30 to run in a 3 cell surefire on 2AA cells.
Still my favourite combination.

Lately I have been pondering the pros of single cell flashlights.
Mainly for me its the fact that you only have one battery to change out.
Meaning if you are in a certain situation you only need to find one battery to get your torch working again.
For me namely an AA cell is the more likely find.
This said I do enjoy a good pocket rocket and wanted a way to enjoy various chemistries in my flashlight without the need for separate parts that screw on, or spacers that slide in and have to be removed or installed whenever loading a different cell type than was previously in the flashlight.
So the plan for me was to come up with a way of using the following cells in a flashlight and only ever needing that flashlight and not having to carry any other "parts" around with me.

With my first design it is possible to use:

CR123
RCR123
AA(any chemistry)
14500

The second design was changed to allow use of all the above cells plus 17500 and 18500 Li-ion.

CR123
RCR123
AA(any chemistry)
14500
17500
18500

For demonstration and to prove to myself that I could get this idea to work I used my favourite design....the Surefire P series.(though the light in the pics is actually a solarforce)

The parts I used to make the device are what I could find in the garage in the spare parts box etc What you see used in the design is what I could find to make it work...not make it look pretty.

All you need to have is the correct drop in specifically built to operate from say ~0.8v-4.2v.
The design would operate in any 2 x CR123 tube flashlight so long as the electronics are optimized for the target voltage range. And the tube can fit the cells.
For example a Quark AA head on a Quark 2x123 body. I believe also that fenix have certain lego capabilities ..even mixed with Quarks.
Most of you are probably aware of the latest rendition of the Fenix LD10 that puts out around 170 lumens off 1AA cell. Happy days!!!!

Any way here goes. I will mainly try to let the pictures speak..........sorry about the cellphone pics.

In this pic I actually took the picture before I had cut the vinyl pipe down to the correct length. In actual fact it needs to be the same length as a CR123 cell.

Still I think it illustrates the principle just fine. With the pipe cut to length there is still plenty of space for the AA to slide in with ample support. I have actually tinkered with this again since taking the photo's as the spring was a little too long. The whole unit is now the same length as 2 x CR123.


note. this is the AA, CR123, RCR, 14500 compatible device.

The spring setup inside has also now been heat shrink wrapped for electrical reliability.

This following pics show the beginnings of the second protoype and why it was neccessary to shrink wrap the centre spring/piston to ensure electrical isolation and reliability.
.


The larger spring you can see is a perfect fit for an AA battery and (trust me) a perfect fit inside my SF 6P or other equivalent 2x CR123 lights



In this design the larger spring is actually almost 2XCR123 cells in length. This acheives several things.
1. long enough to firmly hold AA size cells in center of tube
2. ensures a single CR123 cell is held in the optimum postion. ie. the CR123 cell will squash the spring down just enough for a snug fit and not prevent it making a circuit with the center spring.
3. will squash down enough to accomodate 17500 or 18500.(it needs to reduce to 1/2 a CR123 in length.
.


Once installed in the flashlight the end result is my Surefire 6P or other host with a 0.8-4.2v dropin can now use any of the above cells without adding or changing anything else on the light.

If anyone is interested,
I will try to get some more pics of the finished device up and posted when i have time

Interesting idea.

The thing is, though, is that there are darn few low-voltage P60 dropins that perform well with 2xAA @ ~2.4v as far as I know:

(some of the 2xAA data below is from Bigchelis here)
Dereelight Javelin XP-G (0.9-4.2v): ~250 lumens OTF
SolarForce 'R2' (0.9-4.2v): ~100 lumens OTF (56 lumens on 1xAA)
Malkoff M30 X(P?)-E (1.5-5.5v): ~110-120 lumens
Nailbender XP-G (1.2-4.2v from his thread): (latest low-voltage driver hasn't been measured for OTF yet as far as I know)

Even though some of these drivers are rated to operate down to 0.8v, I wonder what they actually do with only 1.2v?

I'd love to have an XP-G with that Fenix driver that can do 100+ lumens OTF from 1xAA @ 1.2v so that could be used in a P60 drop-in, but unfortunately I don't know if we're there yet?

I still say that a SF C3 with a pair of XP-G LED drop-ins (w/ a standard voltage driver & a low-voltage boost driver) is still the ticket for the ultimate in flexibility:
2xAA @ ~250 lumens from the low-voltage drop-in (as a backup unit).
2x 17/8500 & 3x CR123 @ ~300 lumens from the high-voltage drop-in.

The only thing that setup lacks is 1xAA capability, but no biggie IMO. :shrug:
(Plus the SF C3 is somewhat longer than your handier 6P configuration above.)

Interesting thread though, your groundbreaking C3/M30/2xAA thread started a lot of good fun on CPF I'm sure. As we get better drivers and lower Vf LED's, what you're doing could be very useful (& fun - but that goes without saying).

Very nice. I have been working on a design of my own similar to this for a few years now but I have achieved it in a different way. Hopefully my way will be integrated into a custom light at some point.

Thanks for the replys guys.

I had a feeling I'd see you here first Kestrel :twothumbs
I believe you are right about the lack of P60 dropins that perform well off 1AA. We are not quite there yet ...but soon...soon
The emitters, drivers, and even the humble AA primary chemistries are evolving.(NiZn AA cells)
That ~250Lumens dropin sounds very nice!! I still use my M30 in that regard.....have not bought a new P60 dropin for over a year now:mecry:
Just been sitting back and watching.

I guess we could buy LD10's and open them up to use the drivers in our own custom P60 dropins:laughing:.

Maybe another custom insert that lets us use a Fenix/Quark head as a P60 dropin:thinking:

A surefire 6P/C2/Z2/G2 is a large light to run off 1AA. This said I still like it.....it really fits in the hand well, and is a tank.

My plan was to use the Quark 1AA head and the CR123 x2 body. This would make it a fairly compact light considering its capabilities.
I think I will purchase the parts from 4Sevens next chance.

Does anyone know if there are any CR123 x 2 bodies (fenix or quark) that will fit mechanically with the Fenix LD series heads ?????
I would love to know!!

I am going to try and source/ make parts to make some units up more professionally....rather than the bush mechanic job I did with these.


Hey Carrot......I will certainly be keeping an eye out for your custom light. It sounds like my kind of light!!

Rat6P, I have wanted the ability to use both CR123 or AA or any number of interesting chemistries in these form factors for awhile now and I found that there were no satisfactory solutions. I really do not care for swapping bodies on the go or even at all, and the one light I could find that addresses this "need" (the Gerber Omnivore) is quite uninteresting.

I have been searching around for a partner to make my idea(s) a reality (I have contacted a few major flashlight manufacturers, many who were not interested due to the "difficulty" in its creation) and I think I have finally found one. Whether that results in a complete light or simply a body for an existing light is not really up to me, but I will certainly make noise about it when it happens.

Found what looks like an almost perfect solution.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=708-1396-ND

Most of the dimensions seem correct and it should slide into a 2xcr123 tube.
It's possible that with a little cutting and some modification this would do the job perfectly.