# Can anyone make a 24-28 AA battery holder?



## Aaron1100us (Jan 3, 2007)

Hello, I have a crazy request. I was wondering if any of you awsome modders out there are able to build a 24 or 28 AA battery holder to fit into an extended 6D maglite? I was thinking of a custom battery pack but I'm going to need to experiment with a few dummy batteries to find out the highest voltage I can use. Thanks


----------



## Aaron1100us (Jan 3, 2007)

Or could you give me ideas on how to build or something like this? It has to be atleast 24 volts but would like closer to 30-33v. How hard would it be to extend a modamag or FM battery holder? 7AA's long and 4 across would give me 33.6 volts. I could use some dummy AA's to drop voltage down if need be. I'm thinking that would be a way to go, I just need to figure out how to get or build a battery holder.


----------



## LEDcandle (Jan 3, 2007)

Erm, theoretically you can just put 2 modamag 3D12AA batt packs in series and you should have a string of 24 batts x 1.2v = 28.8v and they might be able to fit in the 6D without modding. Am I missing something here? Seems like its possible to do.


----------



## Aaron1100us (Jan 3, 2007)

I was planning on doing that but I was told by someone that putting two or more battery holders in series wasn't a good idea. I was also told that 28.8 volts would get me around 4000 lumens and if I added 4 more AA's, that would be around 7035 lumens. If I could get away with using 2 12AA to 3D holders and one 4AA to 3D holder, that would be great. That way, I could use a few dummy AA's incase 28 batteries would be too much voltage for that bulb. I wonder if it is a resistance issue putting several battery holders together or do you not think that would be a problem? That sure would be the easiest way to go about it. But if I could find someone to make me a single battery holder that could hold the 28 batteries, that would be awsome. I'v also checked on the 12AA to 3D battery holders and the 4AA to 3d on the sandwhich shoppe website and it seems that there aren't any left. I did send an e-mail to see if more will be available but haven't heard back.. Thanks


----------



## LEDcandle (Jan 3, 2007)

In such high current applications, the worry is usually spring meltdown and other resistance points. Some resistance may not be too bad for the bulb either (if its too much overdriven) but of course there's more heat buildup. 

In my Mag150w, I have even used tiny magnets to connect some lose points (7A current) and run the light continuous for about 5 mins (it can smoke newspaper from the front end in 2secs) and the magnets are still alive! Not that that is recommended. 

I believe 2 batt holders in series might be able to hold up, but to reduce resistance, take care of all the weak spots. The tiny spring at the bottom of the mag switch and the 'nipples' on the top of the batt holders. Maybe you can file one down flat so that it connects better to the back of the other. Or even better, solder them together. 

But better to let some of the expert hotwire masters chip in


----------



## Aaron1100us (Jan 3, 2007)

If I can't get someone to build me a custom holder, I'll probably go with the modamag holders and just put them together. Does anyone know for sure if the ModaMag 12AA to 3D holders will fit in an Unbored Mag host? I was told they could and I was told that they couldn't. I think I'll be able to fix the resistance issues if I have to go with the modamag holders.


----------



## LEDcandle (Jan 3, 2007)

The holders will fit, but the batts you use may exceed the holders diameter slightly. I had that problem with my Sanyo 2100/2500s, and hand-bored the mag with a round file for a couple of days, but learnt that at certain angles, the Sanyos could fit into an unbored mag. (the shape is slightly oval so with 4 points pointing inwards it fits)

I tried this on my friend's stock mag and its true; the Sanyos can fit into an unbored mag, though quite snugly. YMMV depending on your batts.

I'm surprised no one has chipped in on this thread. Maybe you can PM modamag and ask him if you can series his holders or ask if he can build u a custom one.


----------



## Aaron1100us (Jan 3, 2007)

Hey, thanks for the reply, that makes me feel better I can do a little hand sanding/grinding if need be. I could even use a cylinder hone. Otherwise, I was going to go with three 9AA to 3D holders for 32.4 volts. That might be too long though. I'd PM'd modamag to see if there would be any more 12Aa to 3D holders but have not heard back. I just PM'd him again to see what he thought about putting three holders together or if he could help with a single holder. Yeah, it sure doesn't seem that there are too many people interested in this. I do thank those of you who are helping me


----------



## LEDcandle (Jan 3, 2007)

If you have access to a cylinder hone, then you have nothing to fear! But one thing to note is that the original mag is anodized on the inside, so after you hone it, it will be bare. 

If there is a tear in the battery jacket and it makes contact with the inner walls, it can cause a dead short. And at that kind of voltage/amperage, it's gonna be scary!! 

Modamags holders are using brass rods as the pillars of the holder, and I don't know why in my case, whether from static or whatever, I get like a 10-15ma current reading when I use my DMM on the back of the batt pack to the flashlight body while it is OFF. 

So there is some kind of small current running around the light even while it is off. That is not enough to cause a short, but it will drain my batts even without using the light. I wrapped up the rods and sprayed the inside of my mag and it fixed the problem.

Not really sure what that was all about, but just letting you know to watch out for dead shorts with bare internals!!


----------



## Aaron1100us (Jan 4, 2007)

Ok, thanks for the tip. If I get this figured out, I'll probably put something like shrink wrap or similar over the battery holder or find a way to keep them from shorting out on the inner wall of the light. I'll need a way to be able to take the batteries out to charge though. Hmmm.


----------



## kevinm (Jan 4, 2007)

If this configuration is to be fairly permanent, why not solder everything together that can be soldered? Use some larger diameter copper wire if you need to make a connection that would noramally be made by the spring. You could even cut the circuit made by the springs and just use the wire. Just keep the springs to hold the batteries in place. The current should then along the path od least resistance. I'm assuming the positive contact at the head of the light is the spring we are worried about.

Kevin


----------



## Aaron1100us (Jan 4, 2007)

If I can come up with a charger that will charge the whole thing at once, then yes, it can be made permanent. I'll have to look around and see what kind of charger I can find.


----------



## reptiles (Jan 31, 2007)

Aaron1100us said:


> If I can come up with a charger that will charge the whole thing at once, then yes, it can be made permanent. I'll have to look around and see what kind of charger I can find.



Marine shops have 24 vdc battery chargers. 

=MM


----------



## liveforphysics (Feb 2, 2007)

Aaron- Look into something called LiPoly. Makeing a 44.4+v cell fit into the 6d mag would be no problem. 

Also, to charge this series array, you will need to wire the pack to charge these cells in indivdual groups of ~3-4. If it is not done this way, you may find yourself with a cell charge reversal in your first or second charge attempt.

I would highly encourage the use of Li Poly for this sort of application over comparitively pathetic NiMH.

Note not to confuse LiPoly with Li Ion, which is fairly limp when it comes to high current draws. LiPoly is easy to find cells in the 10C range. They look like narrow little flat pads.


----------



## paulr (Feb 2, 2007)

This is kind of scary, with that many cells you really have to be concerned about reverse charging as soon as the pack starts running down. Maybe you want bigger cells and a dc-dc converter. Maybe you want a lithium ion pack.


----------

