9 replies to this topic

[blacklion]

Hey guys! Just wanted to share my method of making dummy AA batteries. I recently ordered some UltraFire 14500 batteries so while they arrive, I decided to make these dummies using only materials I already had.

WHAT YOU WILL NEED

• Used Duracel (or similar) AA batteries (2 per dummy)
• Tradewinds 3-Function Light and Laser Pen (or similar metal/plastic tube)
• Dremel (with cutoff wheel and sanding wheel)
• Soldering iron
• Solder + Flux
• Electrical tape
• 12 gauge (or similar) stranded copper wire
• Caliper (or ruler, or measuring tape)
• Hammer
• Pliers
• X-acto knife
• Sandpaper (220 or rougher)
• Nitrile gloves (highly recommended)

Very carefully peel the bottom plastic from the used AA battery and using the X-acto knife remove the bottom plate. You will need 2 bottom plates per each dummy AA you want to make.


Find a tube (metal or plastic) of similar battery diameter, to be used as the dummy's body. I used the bottom part of this Laser and LED pen just because I had a few of these laying around.
NOTE: If you have never used these, i would advise you to buy a few either online or at Walgreens (2x$5). They are very cheap, the circuitry is very straightforward and compact and include 3 batteries. This is what I add to my guns. Write up coming soon.


Only use the metal bottom part. Save the top part.


Straighten the AA plates using a hammer and whatever you have available.


Measure the thickness of the plates so that you know how long the body of the dummy needs to be.


Measure a real AA battery and write the dimensions. A quick calculation and now you know that the pen shell needs to be cut to ~49.96 mm.


Cut the shell of the pen slightly longer.


Carefully grind to correct length.


Remove the insulation from the tip of the pice of wire you will be using.


With the tip of the X-acto knife scratch the surface of the AA plates.


Add some solder to the plate.


Add solder to the tip of the stripped wire and proceed to solder both pieces together. Note that you should spread the copper wires in order to increase contact area.


Sand around the ends of the pen shell and proceed to solder it to the plate. Try not to leave any empty spaces.


Cut the exces wire (at the other side) to appropriate length and repeat previous steps.



Once done it should look like this.


Now grind the excess material until a "smooth" surface is obtained. Do this on both ends.


Once done, add a ball of solder to the top of one side. This will act as the tip on the positive side of the dummy.


Sand the excess solder from the positive tip, until the desired overall length is obtained.


Wrap with ET, and you're done!


I measured the resistance of the dummy and found it to be very small as expected. (This other guy at this other forum using other other materials obtained similar resistance values).


This is how it looks compared to a regular AA battery.


It fits perfectly.


Yes, you could probably buy the dummy batteries off the internet but it wouldn't be as fun. I have not been able to find the resistance value of a real AA dummy battery. If someone has measured it, please share the result as I would like to compare values.

Hope this helps!

EDIT: Fixed image links.

Edited by blacklion, 21 May 2013 - 12:08 PM.

[roboman]

Nice work!

Instead of sacrificing a pen every time, I'd imagine a piece of brass that's about the same size would work just as well, and you could avoid the internal wire entirely, since brass conducts electricity very well. A piece of heat-shrink would probably look better than e-tape, too.

[andtheherois]

This is pretty sweet.

I personally like the "wrap an appropriately sized bolt in tin foil" approach.

[therealnerfjunkies]

This is a pretty good idea but it requires too much work. I'd rather get these, get an appropriate sized bolt, put it in the converter and you have a dummy battery.

[Jeo]

My method...

________________________________________________________________________

Tools/Materials needed...

Solder and Iron
Drill and an assortment of bits
AA-D convertor/AAA-AA convertor
Small length of wire
Wire strippers
12.7/9.5mm dowell
Something flat and metal (I used the blade of a knife but just about anything would work here)
________________________________________________________________________

The materials in question






Mark the dowel at the length of a battery.







Drill a small hole through the centre of the dowel, then counter sink a small recess in each end.



Feed some wire through the dowel and cut it to length. We want a little over on each end.



Strip the end of the wire back.



Place a large blob of solder in the small counter suck recess we made earlier, making sure it has a good connection with the stripped end of wire.



While the solder is still hot, flatten it out with your flat metal object.



Insert the dowel into the adaptor case and we're done! You now have your very own AA dummy battery and D dummy battery.

[blacklion]

My method...

Looks good too! I wanted to use the AAA-AA converter but since I couldn't find them cheap locally, went ahead and worked with what I had available.

Did you measure the resistance (ohms) of your dummies? I want to compare the available methods with the off the shelf dummy batteries.

[Kronos Nerf Mods]

Figured I would just throw this out there:





They are pretty ugly, but have very little resistance, as they conduct the electricity with normal wire.

[DartSlinger]

Figured I would just throw this out there:
*pictures*
They are pretty ugly, but have very little resistance, as they conduct the electricity with normal wire.

What is the metal part made out of? It looks like dimes.

[Kronos Nerf Mods]

What is the metal part made out of? It looks like dimes.

Well the wire is metal, and the actual battery shape is 3D printed. No metal, No dimes.

[Jeo]

Did you measure the resistance (ohms) of your dummies? I want to compare the available methods with the off the shelf dummy batteries.

Haven't checked but I'd imagine it's entirely dependent on the piece of wire you use.