# The A-AA - an alkaline AA battery vampire



## PCC (Mar 8, 2014)

A-AA = Alkaline AA

There was some discussion recently about battery vampires and the concern about alkaline battery leakage. The thought then occurred to me that a plastic light with just two simple brass contacts would be able to handle a leaking alkaline cell and could easily be cleaned and returned to service. This is a build log for that light.

The light engine that I'm using for this project is the now discontinued Nite Ize 3-LED drop-in module for the Mini-Mag. One of the nice things about this drop-in is that it will drain a single battery down to a really low voltage, low enough to have that battery leak.

The body if the light is made from extruded acrylic rod that I had bought for a project that fell through. Since it was paid for I might as well use it.

First order of business, chuck the acrylic rod into the lathe, drill the end with a center drill and place a live center on it to try to prevent the rod from flexing. After that turn the outside down to even out the casting marks:






I decided to polish the body with some fine steel wool followed by further polishing with a cloth. Then I cut ribs I to the now smooth body to give me something. To hold onto:





The end was turned down to a smaller diameter and threaded 20TPI for a tail cap:





Then the boring part begins:





After the boring is done a single groove was cut into the side of the body for its entire length except for the threaded end. The body is then parted off. A bit of masking tape is used to protect the body as I work on the other end of the body. First, the end is bored out then more 20TPI threads are cut into it:















Next comes the tail cap. Chuck a piece of brass into the lathe and drill a hole for a spring then size it as well as cutting an O-ring groove into it:















At this point I was getting tired and didn't take pictures of the next two pieces that I had made. They're the tail cap as well an acrylic piece that holds the brass plunger. Here's the completed tail cap along with the body. The brass plunger is spring loaded to compensate for different battery lengths. 






Next comes the head. Using acrylic, I made a piece that threads onto the body's internal threads. The outside is of a larger diameter, which I'll come to regret later. In this picture, it is being bored for the light engine:





The brass rod is then chucked into the lathe again and this time I'm making the positive contact:





There's a small O-ring between the brass contact and the acrylic piece to seal it from alkali getting into the head:





The drop-in goes into the next piece and that piece threads into the head to provide continuity for the negative side:




















This is how it goes together:





Next, the outer head needs to be made. This was a piece of scrap 7075 I had laying around. Just like making the body, chuck it up, clean it up, bore it out, thread it:




















A lens is needed so I cut down a polycarbonate lens that I had cut too small for another project. It started off at 26mm and ended up at 20mm:





Everything needed to complete this light has been machined so it's just a matter of assembly:















IT'S ALIVE!


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## skyfire (Mar 8, 2014)

love it! it looks great!
thanks for taking the time, and sharing it with us!


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## PCC (Mar 8, 2014)

Thanks! I have some ideas for variant two of this light. The tail cap was a lot more complicated than it needed to be. Next time I'll put the spring loaded plunger in the head and the tail will just be a simple screw in bolt with an O-ring seal.


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## jonwkng (Mar 9, 2014)

Hi, *PCC*!

Thanks for sharing the detailed build process of your light. Like I commented in the other thread that you showed the light, the acrylic body that you can see the AA cell in is a nice touch. Nice build! :thumbsup:


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## TMedina (Mar 9, 2014)

Whoa - that is definitely pretty awesome.


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## gunga (Mar 9, 2014)

Very, very cool


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## mcorp (Mar 9, 2014)

Wow that's one sweet build!!:twothumbs


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## nein166 (Mar 9, 2014)

I gotta put something like this together for the joule thief night lights I use, yours looks great.


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## RI Chevy (Mar 9, 2014)

Awesome work there! But not all of us have a lathe and the metal stock at our disposal.


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## PCC (Mar 9, 2014)

Thanks, guys!


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## HarryN (Mar 13, 2014)

Nice job - always fun to see a real home built. Now we will need to schedule a local GT so you can bring it.

It kind of funny if you think about it.

(joke) Question - what do you do if your flashlights get ruined by alkaline batteries:

a) Normal answer - Use energizer Li cells
b) PCC answer - Build an amazing custom plastic body light.


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## Icarus (Mar 13, 2014)

Very nice! :thumbsup:


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## PCC (Mar 13, 2014)

HarryN said:


> Nice job - always fun to see a real home built. Now we will need to schedule a local GT so you can bring it.
> 
> It kind of funny if you think about it.
> 
> ...


Yeah, I'm just crazy like that. LOL!


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## MRsDNF (Mar 13, 2014)

What an extraordinary effort on an even more extraordinary light. Thanks for all the pictures PCC. You have done a fine job building this light. What did you use to put the groove on the outside of the tube?


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## RI Chevy (Mar 13, 2014)

It is a very unique light!


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## Kestrel (Mar 13, 2014)

Love the transparent body. :thumbsup:

So if I understand things correctly, that light can take P60-dropins ... ? :devil:


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## SchwarzeWolke (Mar 13, 2014)

Really nice and now I'm thinking of doing some vampire...


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## PCC (Mar 13, 2014)

MRsDNF said:


> What an extraordinary effort on an even more extraordinary light. Thanks for all the pictures PCC. You have done a fine job building this light. What did you use to put the groove on the outside of the tube?


I used my threading cutter and just cut straight in for about five thou per groove.




Kestrel said:


> Love the transparent body. :thumbsup:
> 
> So if I understand things correctly, that light can take P60-dropins ... ? :devil:



P60? Maybe V3 or V4 of this light, but, not this one. Speaking of which, I'm thinking of V2 which will be a complete redo of this light and V3 will be a completely new light using a wquiles Joule Thief board.


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## Kestrel (Mar 13, 2014)

PCC said:


> [...] P60? Maybe V3 or V4 of this light, but, not this one. Speaking of which, I'm thinking of V2 which will be a complete redo of this light and V3 will be a completely new light using a wquiles Joule Thief board.


I see now, the aluminum insert reminded me of the P60 dropin form factor but now I see that it's not exactly the same. Still pretty cool.


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## Darvis (Mar 13, 2014)

Excellent build PCC!!!


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## PCC (Mar 13, 2014)

Thanks again!


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## Mr Floppy (Mar 14, 2014)

I was playing around with 3D printers and ABS plastic bodies and the driver scavenged from a solar garden light but this is much nicer. For a start, you have threads! 3D printing and fine threads don't work too well, plus my models aren't great. 

I might have to steal your idea with the groove for the wire to negative. I designed a hole for the wire but it is a bugger trying to thread the wire through as the 3D printer isn't as fine as it could be. Could make the walls thicker I guess, or use a better 3D printing service. 

If haven't thought of it already, D cells!


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## bigchelis (Mar 14, 2014)

Dang PCC, that idea is freaking cool. We need a night hike soon in the bay for sure. I need to check that out in person.

Great job as always.

If the tailcap was just a twistie plastic one, the threads would never corode to accidentally turn on right? So, it would make for a good small twistie. I been throwing away dozens of AA's from misc camping equipment. In hindsight I should have save them for you 


bigC


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## PCC (Mar 14, 2014)

Mr Floppy said:


> I was playing around with 3D printers and ABS plastic bodies and the driver scavenged from a solar garden light but this is much nicer. For a start, you have threads! 3D printing and fine threads don't work too well, plus my models aren't great.
> 
> I might have to steal your idea with the groove for the wire to negative. I designed a hole for the wire but it is a bugger trying to thread the wire through as the 3D printer isn't as fine as it could be. Could make the walls thicker I guess, or use a better 3D printing service.
> 
> If haven't thought of it already, D cells!


Hmm, my nephew just bought a 3D printer and we haven't tried making anything with it, yet (he's coming over today with it to break it in). My original plan was to have him make the bodies using his printer, but, it took too long to get to him and I ran out of patience waiting. I cut the threads at 20TPI for this light thinking that the coarser threads will hold up better to constant use.

No problem using the idea for the external wire. The original design for this light was to use a dumbbell shaped piece of brass plate that would be bent how the copper wire is shaped. That idea changed when I couldn't find my brass plate. 

D cells - haven't given it any thought because I don't have any alkaline cells other than AA, AAA, AAAA (removed from 9V batteries) and 9V batteries. If anyone wants one I guess I could oblige...



bigchelis said:


> Dang PCC, that idea is freaking cool. We need a night hike soon in the bay for sure. I need to check that out in person.
> 
> Great job as always.
> 
> ...


Thanks, bigC. Yes, you are correct, the plastic should hold up well to leaking alkali from alkaline batteries. Wait until I make V2 or V3 of this light. This one, V1, has it's issues and isn't ready for prime time.


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## RI Chevy (Mar 14, 2014)

It would be really cool if you could figure out a way to get the host to light up seeing that it is made of clear plastic! :thumbsup:


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## PCC (Mar 14, 2014)

I had actually thought about that but didn't want to deal with the glare of the light itself glowing.


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## RI Chevy (Mar 14, 2014)

Maybe a nice colored LED?


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## Mr Floppy (Mar 16, 2014)

PCC said:


> Hmm, my nephew just bought a 3D printer and we haven't tried making anything with it, yet (he's coming over today with it to break it in). My original plan was to have him make the bodies using his printer, but, it took too long to get to him and I ran out of patience waiting. I cut the threads at 20TPI for this light thinking that the coarser threads will hold up better to constant use.



It certainly opens up lots of options for various body shapes, and with your lathe, threads are not a problem. The way I designed mine, it is basically notches on a disc and a small turn to lock but it's not tight. Not very nice at all unlike your build.

What's the cost of your build? 3D printing isn't cheap. I used to use the cheap plastic Dorcy frostbrites as disposable hosts but when you get a leak in one of those, even then it was annoying after the effort of making it. That's when I decided to try 3D printing to isolate the driver and head, and to make lanterns instead as carrying one of those things when it leaks in your pocket is worse.


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## PCC (Mar 16, 2014)

I'm guessing I have around $15 in that thing. The module cost was the most and the rest was either scrap or very inexpensive.


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## Bimmerboy (Mar 29, 2014)

This thing is PCC (Pretty Cracking Cool)!! Oh, wait... that name's been taken. :devil:

Looking forward to the revisions, and if I may ask... will they be available for sale?

I'll gladly change the name of the dog mod if you call this the Personal Catastrophe Candle... lol.


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## PCC (Mar 29, 2014)

This first one will be redone as I'm not entirely happy with the way it turned out. V2 will be more compact and might have some GITD elements in it. V3 will use a different light engine altogether. Might be a few months out, though, as I've got something to make this coming month that has a deadline associated with it.


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## RI Chevy (Mar 30, 2014)

I'll take the 2nd one!


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## Bullzeyebill (Mar 30, 2014)

I'll back up #2. LOL. Actually, I would buy one of these, if you are inclined to make some for sale.

Bill


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## gunga (Mar 30, 2014)

Me too!


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## archimedes (Mar 30, 2014)

Yep, I'd like to buy one of these ....


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## PCC (Mar 30, 2014)

Hmm, didn't anticipate there being demand for these. I'll put up an ad for them when I'm ready to make them.


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## RI Chevy (Mar 30, 2014)

Excellent! :thumbsup:


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## Mr Floppy (Mar 31, 2014)

Not everyone has the Niteize 3-LED dropin but the E01 head is a pretty good substitute. You can use it whole and totally encased in the head of the host, sort of like this






It's my alien in the body, the E01 head in a cheapie AA light from Fasttech. I removed the reflector and "pill" and used a PCB board and spring to make the bridge from the body to the E01 contacts. It relies on the spring to keep the contact together but a well designed, tight fitting head would do a better job. I was trying to fashion something like that from 3D printing but have yet to get it right.


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## gunga (Mar 31, 2014)

Ooh. I like that idea too...


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## PCC (Apr 1, 2014)

I've decided to move forward to what I've been referring to as V3 of this light. It's going to use the wquiles Joule Thief board, XM-L2 (lower Vf for more draining power) and a 17mm reflector.


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## gunga (Apr 1, 2014)

Neutral XML2 I hope?


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## bshanahan14rulz (Apr 1, 2014)

Is there already gathered, information about how our high power LEDs perform at ultra low drive currents? i.e. do different LEDs have different thresholds for on, or do they all light up to some extent with tiny amounts of current? I've got a drawer full of used AAs. Not sure why, but I could claim that this is why, and build one of these battery vampires


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## dealgrabber2002 (Apr 1, 2014)

Oh, i am a sucker for AA and joule thief... I want one!

Wouldn't an xp-e2 be better for low power light?


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## Bullzeyebill (Apr 1, 2014)

Let's let the Master do his thing.

Bill


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## PCC (Apr 1, 2014)

bshanahan14rulz said:


> Is there already gathered, information about how our high power LEDs perform at ultra low drive currents? i.e. do different LEDs have different thresholds for on, or do they all light up to some extent with tiny amounts of current? I've got a drawer full of used AAs. Not sure why, but I could claim that this is why, and build one of these battery vampires



Thats a question I've been trying to figure out for a while now.



dealgrabber2002 said:


> Oh, i am a sucker for AA and joule thief... I want one!
> 
> Wouldn't an xp-e2 be better for low power light?



I'm guessing that the only real way to answer this question is to build one and do some testing.



Bullzeyebill said:


> Let's let the Master do his thing.
> 
> Bill


LOL! Master? Hardly! I'm just an enthusiast like you folks are. I'm just crazy enough to buy and learn to use a lathe to allow my creative alter ego have some fun


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## dealgrabber2002 (Apr 15, 2014)

Any updates?


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## PCC (Apr 15, 2014)

I'm on a staycation* in two days. I am going to be working on this during that time. Should be done in about a week. It'll take longer than normal because I need to extensively document the build.

*staycation = stay at home vacation


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## RI Chevy (Apr 15, 2014)

LOL  :laughing:


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## HarryN (Apr 18, 2014)

In the past I did some testing on very low drive currents for power LEDs. Maybe it still applies, maybe not.

Vf - As expected, lower currents often lead to lower effective Vf. The LED mfgs have worked to make their LEDs less Vf sensitive, so this effect might be less today.

Red shift - The phos is usually formulated to produce a specific spectra under a specific blue light excitation level. Again, the mfgs have gotten better at reducing this sensitivity, but the common effect in the past was for low currents to produce some "red shifting" of the spectra.

Lifetime - power led run at low drive currents - it gets difficult to even measure the lifetime increase because it is so long.

Isn't it funny what projects capture the imagination ? Have fun with your light build and try to not destroy your life in the process.


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## Bimmerboy (Apr 18, 2014)

PCC said:


> I'm on a staycation* in two days. I am going to be working on this during that time. Should be done in about a week. It'll take longer than normal because I need to extensively document the build.


So long as it's fun, and only if you even want to sell these in the first place!

Either way, I'm enjoying the build log, and hope you are too. Thanks, PCC.


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## PCC (Apr 18, 2014)

No problem with making a few for members here. It's all good. I should be getting this going tomorrow.


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## gunga (Apr 18, 2014)

Ooooh. Waiting...


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## RI Chevy (Apr 19, 2014)




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## PCC (Apr 19, 2014)

It's begun...


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## gunga (Apr 19, 2014)

Sheesh. Looks great already!


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## dealgrabber2002 (Apr 19, 2014)

What emitter will you test out first?


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## PCC (Apr 19, 2014)

XP-E R4 because I already have two and I'm hoping that the smaller die works better with low input current. The XP-G2 has a lower Vf, though. I'll have to do some experimentation to see how things go. Worst comes to worst I'll throw a red XP-E in there.


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## dealgrabber2002 (Apr 27, 2014)

Xp-e is good


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## dealgrabber2002 (May 4, 2014)

Reading another thread reminded me of this one. How are things going with this project?


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## PCC (May 4, 2014)

Stalled. Things are busy both on the home front as well as work leaving me with just enough time to unwind at the end of the day and not much else. I guess you could say that I need to unwind in front of the lathe...


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## dealgrabber2002 (Aug 4, 2014)

Any updates? I completely forgot about this thread.


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## RI Chevy (Aug 4, 2014)




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## pimaxc (Aug 5, 2014)

Awesome build, count me in as one of the people that want one if you ever decide to make a bunch.


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## PCC (Aug 24, 2014)

Sorry, been out of it lately and this project has been shelved. I might just build the one I started and that's about it.


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## dealgrabber2002 (Aug 25, 2014)

sorry to hear that.


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