Test of aluplate<->sand-graphite-tablesalt battery cell

[hartiberlin]

Hi Gast, you are right, I just put the meter probe onto the mix.
As the graphite is pretty conductive, this is pretty okay.
Yes, you can get more current out, if you would put a graphite plate onto the mix
at the top, but graphite plates are expensive!

You can get the same current out with a different method, that I will not yet reveal
over here.

Yes, a small current during the drying process really helps.
This can be done easily by applying a resistor load to the cell.
This helps to form the crystals  in the right direction, so the
current later is bigger.

The big question still is, if the cell will also work, when all
water is evapourated out of the mix.
I have now re-weted the mix and now just let it dry outside
slowly in the sun.

When it was reweted, the cell again puts out 0.66 Volts and
around 10 mA .

Regards, Stefan.

[gast]

>> Yes, you can get more current out, if you would put a graphite plate onto the mix
>> at the top, but graphite plates are expensive!
What about an empty beverage can made from aluminium and a graphite rod from an pencil in the middle of the can?
(a composition like a normal battery. Maybe you can open and wear away an old 1,5 Volt battery which is made from zinc and graphit and fill in your own stuff)

>> Yes, a small current during the drying process really helps.
Oh, did you still verify it?

>> When it was reweted, the cell again puts out 0.66 Volts and around 10 mA.
Hmmm, but this sounds more like a normal elecrtrolytical reaction. Nothing what is caused by the cristaline structure.

[hartiberlin]

Yes, this can be done, using an empty beverage can, but they normally
have not aluminium but other metal alloys, so the voltage can be lower
and you have to make sure you put out the plastic coating of it on the
inner walls.
But as the surface mainly matters it is better to put the graphite-salt mix
better on larger plates or bigger sizzed alufoils and thus get more output current this way.

Also if you use Zamak alloy you have a much longer lasting time of the metals,
but Zamak is harder to get than alufoil, which you can buy in every supermarket.

Yes, the current helps to build up a better cells. Walter Hofmann has
already done this and has first seen it.
When I applied the heat from the oven and shortcircuited the cell
during heating, the current did rise and afterwards had a bigger value,
so it helps to have a current running during the crystal forming process.

Yes, I agree, when the graphite-salt-mix is wet the cell just works mainly
on the galvanic process and uses up the aluminium metal.

Regards. Stefan.

[gast]

Sorry Stefan, but what is "zamak alloy"? Alloy = "legierung", but zamak... I don't know.

>> When I applied the heat from the oven and shortcircuited the cell
>> during heating, the current did rise and afterwards had a bigger value,
Hm, shortcutting the cell will result in a current with an max amount which the cell is able to produce at this moment.
So if the cell is low on power it will result in an lower current for the forming-process.
Did Walter Hofmann (or you) test the forming process using a higher current provide by an external power source?

Regards Gast

[hartiberlin]

Have a look at:

http://www.matweb.com/search/SpecificMaterial.asp?bassnum=MZN40A

and

http://www.matweb.com/search/SpecificMaterial.asp?bassnum=MZN43A

No, I have not yet tested an external bigger current.
That might be a good idea to try.

Do you think it should be pulsed DC or just only DC current ?

Regards, Stefan.