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[Strife26]

Pretty simple: Design a battery build-able from parts that Strife can find in his area less than one pound in weight with the most power.


This challenge is only tangentially related to a physics project.

[Siquo]

Hmmmm...
A falling egg, a battery, what's next, home-made Plastique?

Be careful of the Homeland 'Security' there, son. 

[Heron TSG]

Well, what you need is a capacitor, Strife.

After school I'll bring my DC electronics notebook up here and give you the lowdown on what all you'll need, and what will effect the capacitor's farad count the most.

This will be interesting.

[Aqizzar]

Next it'll be a catapult.  That's what it was for me.  Or catching bugs like I also had to do (and failed at).

Re: battery parts - You know exactly what's coming.  Or maybe orichalcum, beats me.

[eerr]

You really can power batteries with small fruits and bits of wire.

I was always amused by (Hey) Arnold's potato clock though.

You could probably mange something out of lead, and orange juice if you preferred. Don't know wether you'd need a cathode or anode.

[userpay]

Ye gonna be doing catapults down the line? That I can help with. My trebuchet threw potatos second farthest out of all the physics classes, I'm not even in honors. I think I may have made a topic here somewhere I'll see if i can find it.
edit: Guess I didn't post it here, I can post vids and pics if ye'd like though.

[Pillow_Killer]

Screw fruits. We had that challenge when we were in school, something like, five years ago or so. Anyway, buy some sulphuric acid, 10% one. You can easily find that in automobile parts shops and such, pour it into glass jar, and plug in two electrodes, iron and bronze. Add wires, and You'll probably get around 1,5-2V out of it.
-edit-
Hm, wait, a pound... Pound is about .45 kilo, so I dont know if YOu'll manage that. Try, at least.
-edit2-
Alternatively, take a stack of copper and aluminium coins, preferably same size. Then, cut some circles out of paper, thick one preferably; Carton wont work. Then soak them in a heavy solution of usual cooking salt. Now stack em like this:
Copper coin
Paper
Aluminium coin
Paper
Copper coin
Paper
Aluminium coin
Et cetera.
Gotta make a case for it too.
Et cetera.

[Siquo]

Ah, but now comes the question: he needs power, but for what.
A capacitor (aluminium-foil and an isolator rolled up will do) can deliver much more power in a shorter timespan.
The acid-battery can deliver much more power over a longer period.


So, are you building a taser or a flashlight?

[Itnetlolor]

You can always make a Baghdad Battery. Clay pot, filled with acidic substance (like lemonade or something), Copper and Aluminum coils inside and sealed with asphalt.

It might be scalable to fit within a pound.

Or we can scrap the clay pot overall, and just make long coils and plunge them into a huge stack of lemons. Shishkabob-battery.

[eerr]

If the battery doesn't need to last, then you can probably pick out some of the most chemically reactive cathodes, anodes, and electrolytes possible.

I wonder if  raw sodium-ammonia-copper would work?(raw sodium is far too dangerous to handle for a high-school project.)

[ToonyMan]

1.  One or two capacitors.
2.  A transformer.
3.  A bridge rectifier.
4. 
5.  Profit!

My whole trimester this year has been on damn power supplies.

EDIT:  Hold on, let me draw one.

Spoiler (click to show/hide)

Also, make sure not to kill yourself.

[Virex]

If the battery doesn't need to last, then you can probably pick out some of the most chemically reactive cathodes, anodes, and electrolytes possible.

I wonder if  raw sodium-ammonia-copper would work?(raw sodium is far too dangerous to handle for a high-school project.)

Why would you want to try that? The sodium will probably react imediatly with any water present, and failing that, with the amonia itself. Even if you'd be able to split the half-reactions so you can make a batery, you'd get a short burst of several amps and then nothing (well, possibly hydrogen gas)

[Strife26]

Well, I'll say that the original design for this project was rejected. Something about "shotgun shells not allowed in school"

[userpay]

Well, I'll say that the original design for this project was rejected. Something about "shotgun shells not allowed in school"

lol, shooting off shells with an electrice current?

[Heron TSG]

Basically, this is what you need.


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The yellow lines are your leads, the red is your dielectric, and the green are your plates. The idea is that an electric field builds up between the plates, and a few factors [stated below] effect its strength.

The greatest amount of farads you can cram into it would be from maximizing these factors.

*extremely wide plates
*extremely close-together plates.
*Using a powerful dielectric. (Mineral oil is a cheap and effective one, and ceramics work too.)