Intercalated graphite carries a resting voltage without giving a charge.

[kajunbee]

What I noticed in my test was the voltage was lower when I first formed the cell. After the first 10 second warming period the voltage increased. Now I'm not sure which way I should look at this. Did the warming lower its ionic resistance. Or did removing some of the water raise the salt concentration which lowered the resistance. Or a combination of the two. https://en.m.wikipedia.org/wiki/Aluminium–air_battery

[Jimboot]

Still at 1.18 this morning I built it two weeks ago.  I think I need to go and buy an analogue meter. It will be interesting to see the effect as when I remove the dmm the voltage rises.

[sm0ky2]

Earth ground will always introduce those low-amplitude feedback signals
Partially telluric currents, partially underground television cables
(and yes with an Amp and filters you can watch tv from an earth battery signal)


But, 0 will always be 0 unless your other reference is a different part of earth.


With an ungrounded scope, 0 is the scope case, and what you are measuring could
be at any potential until you try to measure it.
At which point it is referenced to the scope.
Why does this matter?
Normally it doesn't.
The scope shielded case has a high inductance.
but if it's sitting on a metal desk and the cooling fan is blowing charged air onto it
the scope takes on a charge (and the desk oppositely)
Which makes 0 not 0.
(in which case everything would take on a voltage when you try to measure it)


There are many ways in which we can measure a potential.
When my PC is on, my desk measures +4.3v  with respect to earth fairly consistently.
(fatal flaw in electronics, ground everything to the case but the PSU to earth)


Once you eliminate every other possibility, and are still unable to discharge the material
Feel free to classify it as
an Electret
Category: 1n

[Jimboot]

.

[Jimboot]

Thanks Smoky.

I bought a passive analogue meter. Over the 3k resistor I get around 100mv. Leaves me scratching my head.
Every time I measure seems to get less and less so what ever it is looks like I'm dissipating heat?