Tiny Lithium Batteries

[nbk2000]

I was at K-Mart recently and, while browsing the fishing supply aisle, found a very intersting item.

It was a battery for flashing floats, used for night fishing presumably. What was really interesting was the dimensions of these batteries, less than 4 millimeters in diameter and about 35mm in length.

In other words, small enough to fit in the metal cartridge of a pen refill or the drilled out core of a pencil. ;)

The batteries are 3volt, and in a package of two, for $5.

What could you do with such a tiny battery?

[FUTI]

Use it as energy source for timer which triger primary charge of explosive device is my first idea. Some of the pencils come with electronic watch;)

I believe that I read somewhere about making stunt device (only one discharge) out of small batteries...I will google it to see if I can find it again.

[thrall]

What could we do with such a tiny battery!!!!
Look at the section this post is posted in;).
Here are the produst specs. :cool:
http://www.quality-items-flashlights.com/product_info.php?products_id=109
For a closer view of the THING
http://ledmuseum.home.att.net/microe.htm
Third picture.
Here is another link
http://www.amicell.co.il/b_limno2.htm

But the weight of battery(BR435) in the two links has discrepency :( (one says .85 grams and another says 6 grams)
Anyway what about BR425 and BR211 ;)

[Corona]

Electrically fired pen gun....

[thrall]

Or a letter bomb....................:cool:

[A-BOMB]

You could make a tiny timer/det/battery unit with those insided of a weapon stabbing weapon, first stab injects unit then boom, or a mini grenades made out of pens and the like.

[DinamiX]

I has recently stopped my pyromaking tendancy (because of a dumbass-smoke bomb power underestimating accident), but I'm still interested in electronics: so i've made a REALLY EASY TO DO :D timer device for detonation.

It consists of an electric watch with an alarm connected to a transistor which amplify the electric signal incomming to the mini-speaker. The transistor engages a small relay that starts an electric detonator (I've made one with a tiny bulb filled with BP).

The only problem of this device is that it needs a 9v battery, that quadruples the size of the whole thing. With your batteries, it will be small enough to be directly integrated in your *Materials*.

If you find a watch that's small enough, you even would be able to integrate the whole thing in a pen. :)

[A-BOMB]

There is an even easier timer, using a capacitor, transitor, resistor and battery(and a switch if you want to go luxury). You charge the capacitor to a specific voltage(dictated by the battery in this case) and connect it with the resistor to the transitor in the was that it keeps the circuit open till the capacitor is depleted, then the transistor closes the circuit with the detonator and battery. boom! You would have to experiment with the capacitor/resistor arrangement, to find the right combination for the time you need,(you could maybe use a varible resistor to vary the time) But once you found the right combination you could put all the compents battery/timer/det/switch all into a pen, just stab it into you block of explosive and click-click(not unlike that james bond movie with the explosive pen)

[DinamiX]

I've alredy done a timer like you are saying, but the advantage of the watch based system is that you can configure a 1 second precision time and let it up to 24 hours. Compared to a resistor who has a maximal precision of +-5% (which makes +-30 minutes for 10 hrs). Also, if you want to change the time, one the device installed, it would be impossible.

In the other case, the capacitor system is good for a small time: like 10 seconds. In fact, i uses it instead of a long fuse.

By the way The pen was just an example to show the miniaturisation :D

[FireBomb]

I would think that the size and weight of these batteries would make it perfect for use in a homemade rocketry, or other such devices which require lightweight small components such as this.

[mongo blongo]

DinamiX- What transistor were you using to get saturation off such a small voltage? I have been looking for such a transistor for some time.
Has anyone seen these batterys in the UK? I can't find them, even from the most popular electronics suppliers.

[DinamiX]

Mongo, any transistor that you can find will do the job (I found mine in a broken TV), but actually, the system i made used 2 transistors instead of 1 and also a capacitor:

The first transistor amplifyes the sound and is connected to a capacitor/resistor circuit that converts the electric signal to constant DC (else your relay would go constantly on/off). Then there's another transistor that amplify the DC to be of sufficient voltage for engaging the relay...


And about batteries, there exists other pretty small batteries, like the A23 used for alarms and remote systems.It's 10mm diameter x 28mm long, and it produces 12v, which is sufficient for almost all circuits we make. They arent as small as nbk's, but it's not hard to find and you can by it for 1$ (I buy only cheap brands, because the same duracell battery costs 8$! And anyway I dont care of it's lifetime because the lifetime of all things i uses rarely exceeds 1sec :) ). If you need them, they are generally classed as LR23A, LRV08 or MN21.

[nbk2000]

These would be good for small projectile munitions, as it's lithium (cold-tolerant/long-life), very small and light, and has decent voltage.

I was thinking that the insulated battery could be free-floating in a slightly larger diameter tube of insulator material, with a small spring around it, and two crimp rings on both ends of the tube, the front one be affixed, and the back one lightly connected to the back end.

Upon set back from firing, the battery would be forced back into the rear crimp ring, that would latch onto it.

Upon impact, the battery, with the now attached one-half of the firing circuit, would slam forward into the other crimp ring, completing the circuit and exploding the munition.

I'd imagine there'd be a small delay in the initation, measured in milliseconds, which might be put to good use in a wall-penetrating munition to allow it to explode inside the target structure, instead of against the outside wall like it would if it was instantaneous.

[thrall]

What about this
http://www.powerpaper.com/5_news_pr/pr030902.htm :cool:

[Jacks Complete]

You could use it as a power supply for a small tazer-like projectile. Just wire it so that the voltage is tripled or more, then it will cause all sorts of problems once the skin is broken, as all the muscles contract. AC would be best.

Another idea would be to use it for the chemicals inside it as well as the power it puts out - lithium reacts with water, and hence blood, to form hydrogen and heat, which wouldn't be fun if you had just been shot with it, either.

Combine the two, and it would be a bullet that hit fairly hard, and ensured knockdown if the skin was broken, along with caustic burns and severe out-gassing, all in one. Just file the case down so it ruptures, or notch it so it shears open.

As for things with power requirements, well, there are plenty of ideas for light seeking projectiles out there, or radio controlled, etc. which need very small components. If anyone would make and sell cheap quadrant detectors, the way would be open for these.

Finally, take the case off, and use the reaction of the lithium with water to make hydrogen, and burn the hydrogen for thrust, letting you make a small ramjet projectile or rocket motor that is powered by water.

On a different note, where did your new sig come from, NBK?

[nbk2000]

The sig's from The 38 Strategems. A book about ancient chinese martial strategies, like Sun Tzu's Art of War.

It means to give something in the hopes of attracting something of greater value, but, instead, ending up getting something even less valuable back.

The equivalent of "Casting pearls before swine". ;)

They know who they are.