Some Rolled Earth Battery Capacitor Questions

[YoderIII]

I built a rolled earth battery capacitor. It is about 12" across. I used 200 square feet of metal with a different metal 3/4 core pipe. I used a plastic type mesh material with a 10 year in ground life span.

I understand that the the thicker the plastic mesh material the more capacitance my earth battery will have. What are the limits and how do I test? It takes several hours to roll an earth battery capacitor.

Right now I have it in a salt water bucket for testing purposes. I will soon put it into the ground outside.

I need some help on the readings of my multimeter. (I always have trouble)

AC Voltage
750 Setting I get reading of 001
200 setting I get 00.8

DC Voltages
1000 Setting I get 001
200 Setting I get 00.6
20 Setting I get 0.62
2000m setting I get 614

DC Currents 
10A Setting I get 0.01
200ma Setting I get 126.0 (about)
20ma Setting I get 16.49

So how many volts do I have?

Thank You for your help.

[gyulasun]

Hi,

From your voltage readings the most probable truth is DC 614mV in the 2000mV setting.
The current reading is probably believable for the 16.49mA in the 20mA range. The 126mA current in the 200mA range is doubtful though not impossible, hopefully you have a trusty meter in that range too.
I comment this purely by analyzing your data.

Here is a low voltage Joule thief circuit operating from a 550mV copper-zinc home made battery, consuming about 15mA current:
http://madscientisthut.com/wordpress/daily-blog/joule-thief-copper-zinc-battery-experiment/ 

So I suggest your trying to build the circuit and see 'visually' how long the earth battery could run it.  OF course you can substitute this circuit with a resistor to load the earth battery, the resistor value could be 0.6V/0.015A=42 Ohm (I rounded up from 40) and occasionally you could take voltage measurements across this resistor to learn about the battery voltage.  On Joule thief circuits you can find pleanty info on the forum.

Gyula

[nul-points]

I built a rolled earth battery capacitor. It is about 12" across. I used 200 square feet of metal with a different metal 3/4 core pipe. I used a plastic type mesh material with a 10 year in ground life span.

I understand that the the thicker the plastic mesh material the more capacitance my earth battery will have
[...]

Thank You for your help.

it sounds like you've mostly made a battery - one electrode is a roll of metal sheet, the other is just a rod - not much area in common for a capacitor - but construction is similar to some battery technologies

BTW, just for reference i think you'll find that capacitance decreases with thickness of separator

[...]
DC Voltages
[...]
2000m setting I get 614

DC Currents 
[...]
200ma Setting I get 126.0 (about)
[...]

So how many volts do I have?

almost twice as much as Bill Mehess 

(614mV)

but your current is probably 100s of times larger!

126mA (the difference in short-circuit meter current readings due to different internal shunt resistance for the different current ranges)

...so you'll probably be able to run quite a powerful Joule Thief from your 'Earth Battery'

hope this helps
np


http://docsfreelunch.blogspot.com


[EDIT - oops - crossed post with Gyula - forget i spoke!  ]

[gyulasun]

[EDIT - oops - crossed post with Gyula - forget i spoke!  ]

   

LOL   

By the way I agree with you on the inner resistance differences of the different measurement ranges of course and this is here accompanied by a non-linear load dependent inner resistance of such an earth battery.

Greetings,  Gyula

[nul-points]

[...]
... and this is here accompanied by a non-linear load dependent inner resistance of such an earth battery.

Greetings,  Gyula

hi Gyula - yes, good point!