Picture of Make A Water Bottle Capacitor
Do you have loads of water or soda or frizzy bottles everywhere in your house and want to use them for something good?

Well, here is one good use of them, make a High Voltage Water Bottle Capacitor! The bottle capacitor is very similar to the Water Leyden Jar I made a while ago, but the only difference is it uses a bottle, not a jar.

The bottle capacitor is a high voltage capacitor, high voltage capacitors are one of the most dangerous things you could ever use in electronics. A large charged bottle capacitor is potentially lethal if you touch its live terminals, and a small charged bottle capacitor can cause injury and it still be lethal in some ways.
So, I am not responsible what ever you do with this information and bottle capacitor.

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Step 1: What you will need...

Picture of What you will need...
What you will need are:

  • A bottle of any kind
  • Water
  • Salt
  • Stainless steel nail
  • Aluminum foil (or even better, use AL foil tape if you have any!)
  • Tape (you won't need it if you are going to use foil tape

Step 2: And the tools...

Picture of And the tools...
Not much tools is needed to make a bottle capacitor.

  • Hammer
  • Hot glue (or anything to seal up the container to prevent water coming out)

I think that is just about it.

Step 3: Take the sticky stuff off!

Picture of Take the sticky stuff off!
Before we start making a bottle capacitor, take all of that sticky stuff off! It can reduce the performance of the bottle capacitor, or even cause problems if you don't take the sticky tags off!

Step 4: Fill it up!

Picture of Fill it up!
Fill the bottle with warm water.

Step 5: Add in the salt...

Picture of Add in the salt...
Add a few teaspoons of table salt, and stir well! After that, put the cap of the bottle back on.

Step 6: Hammer in the nail!

Picture of Hammer in the nail!
Hammer in the nail in the center of the cap, and leave the head of the nail about a centimeter away from the cap.

Step 7: Seal it.

Picture of Seal it.
After that, put some hot glue around the nail and the cap to stop the water coming out.

Step 8: Wrap the bottle with foil...

Picture of Wrap the bottle with foil...
Cut out a sheet a foil that will wrap nicely around the bottle. Then wrap the foil around the bottle, I used tape to hold the foil onto the bottle. You can use glue if you want, but don't use flammable glue because of sparks, it is likely to catch on fire, or maybe even explode... Then I soothed the foil down onto the bottle to increase the efficiency of the bottle capacitor.

You can use something much much better than foil if you have, use foil tape. You can just simply tape around the bottle and not have a hard time wrapping the bottle with foil and tape (or glue).

Step 9: Attach the wire to the foil...

Picture of Attach the wire to the foil...
Attach a piece wire to the foil of the bottle - that would be the negative terminal of the capacitor, the nail on the top is the positive terminal,

Step 10: Completed!

Picture of Completed!
There! You made a bottle capacitor!

I also added a magnet and a ball to give it a "Leyden Jar" like.

I measured the capacitance of my bottle capacitor and my meter reads 1842pF (1.8nF)! That is very high for a cheap high voltage capacitor!

Step 11: What to use it for.

Picture of What to use it for.
If you want to electrostaticly charge your bottle capacitor, read this site, it will show you how to make a simplest charger you can ever make.

Or even far more dangerous, treat it as a normal high voltage capacitor, you can use it as a capacitor bank for the tesla coil, or something like that.
I tested my bottle capacitor with high voltage power supply to see if it works. Never ever try that, unless you have good experiences with high voltage.

Well, I hoped you enjoyed this instructable!
If you have any questions, or need help, or found an error, or anything, make a comment! I like comments! :)
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yonatan2419 hours ago

If there is one nail, where are the negative and positive connections?

zain_de1 month ago

Hi Mr.Plasmana,

I made my water bottle capacitor and its rating is 1.3uf that's cool and cheap capacitor i ever made; but how to recharge it? Plzzz help me.

MaryP63 months ago

what is this good for? What specific application would someone use this on?


Doctor90250 4 months ago
to slaserj: this is normal . it simply means that the salt and the top electrode created a reaction, taking metal from the nail or wire and drawing it into the solution. look up simple metal plating and youll understand that a little better. if you put copper on the neg of a battery and a quarter on the positive and submerged the 2 in vinegar, youd eventually copper plate the quarter and copper ions were drawn from the copper, through the vinegar and adhere to the positively charged quarter, and youd be left with a solution of copper chloride.
Juan-PabloG6 months ago

This is great! have you seen any build up of sodium in the bottle's inner surface?

nschreiber081310 months ago

Dear: Plamana

I am hoping to build my own capacitor but I have to ask you this. You see I am trying to build my own Ionocraft but there are a few problems. Ionocrafts need powerful capacitors but how powerful. So what I am trying to ask you is what is the break down voltage, resistance, watts, volts, amps, and farads of your capacitor. Also how would you determine it with a different capacitor.

Thanks :)

From: Noah

can you tell me how much high voltage you give the capacitor

Sarthak311 year ago

Will this capacitor work with ac current and can i charge it with a flyback transformer

I read about caps replacing batts. hOW DO WE do this?
can you come up with an instructable about this ?

i completed this project but the method but the PVC method is more of a exercise than a way to generate static

Thanks for posting this. I built mine and checked my multimeter for capacitance and it's 2.1nF. Cool project!
ewcrew1 year ago
would it be possible to use this to make an EMP?
(Not that I am thinking of making one I am just wondering)
You'll have to use around 8-10 of them.
j_herzog1 year ago
I hooked three of these in a parallel sequence and got a HUGE discharge
sgfidlin1 year ago
How long will it keep a charge for? Also, how could i disable it if i didn't want it any more?
Hi I built this and it does nothing. Can you help me?
what are you charging it with?
ghest11382 years ago
I'm trying to make a mini one out of an aprox. 2*0.5 plastic cylinder w/ one closed end that I got out of a pen. I've filled it w/ salt water, wrapped it with foil, attached the - wire, and to seal the top, I first put electrical tape over it, then I inserted a small nail, then I put clear Gorilla Glue around it to seal it. I was wondering if this would work, and if it did, how much voltage might it put out? Enough to light an LED?
I still think its a neat concept though
This does nothing. I even hooked it up to an AC four wheeler charger.
bswt3 years ago
if you heat the water in a pan then add the salt you could add more
iTixle bswt2 years ago
This extra salt will only stay dissolved when the water is hot. Once the water cools down the solubility of the salt in the water will go down and the salt will precipitate out of solution.
Blad20112 years ago
how do you do step 11
hilo8906 years ago
how should I charge the leyden jar? I ran it across a tv and it did nothing. I don't have any PVC pipe either.
use a test light hooked up to the positive terminal of the capacitor. hook the negative up to the negative terminal of your car battery. touch the other end of the test light to the positive of the car battery and hold it there til the test light goes dim. ta da! fully charged!
isnt that dangerous?
i just joined instructales.com today.
your bottle capacitor is amazing.
adelkamel2 years ago
Dear Plasmana
Thinks for your good idea. I want to ask you about voltage achieved by the cap, if i need a capacitor of 300pF and 10KV, what can i do?
Best regard
Adel Kamel
tanujswain3 years ago
can pls summerise the many ways to charge it...
bshaikh3 years ago
can i use normal 1.2 volt battery to charge...........i dnt think it will be dangerous?plz reply.............thnx
SpeedSicks6 years ago
has anyone used one of these to help buffer the power surges in a car audio setup? i used to have a 1 farad power capacitor in my car, and it worked great for hitting the extra low bass, and stopped my headlights from dimming with the bass also. but they are expensive..this could be cheap, and made right could be safe ? lol
i dunno if they are safe, but i guess they are way more than 1 farad...
I realize that these comments are old, but I would like to clear some things up. There is a reason that 1 Farad capacitors for audio systems are expensive. Capacitors that hold 1 Farad and above are expensive because that is a huge amount of energy to store. Capacitors are typically rated for MICROfarads, micro meaning one-millionth. Bigger does not always mean better in the world of capacitors. Although these capacitors may be relatively large, these only hold on the order of a few NANOfarads. You would potentially need one BILLION of these in order to add up to one Farad. The capacitor in this Instructable would typically be used for a Tesla coil, or something similar.
The problem with the homemade one is that it's not electrolytic, and therefore probably very low tolerance. It would also be very susceptible to temperature, impact, and air pressure. I have no way of knowing, but one bottle alone is probably not 1 farad. A bunch in parallel probably could be, but not just one.
dariel245 years ago
hmm it wont work.. i use 600ml bottle with 20g salt, cover it with aluminum foil and wrap it using black electrical tape.
but for a nail substitute i use the graphite core of a battery. is that my problem?
tested using 3v DC from my home-made Transformer, but it didn't store any electricity
from what ive read a capacitor needs to be grounded while charging , you might want to check the wikipedia page on leyden jars
ARJOON dariel244 years ago
your voltage was too low. this capacitor won't store your charge for more than 3s
dariel24 ARJOON4 years ago
kinda... epic my question took almost 1 year to be replied
thanks by the way, how much voltage should i use? 12?
ARJOON dariel244 years ago
no. maybe a few thousand volts will do.
maz-zahra4 years ago
I have a task. I have to make a capacitor and its size must be 3cm X 3cm X 3cm. Would you like give me any suggestion for the materials that should be use?
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