Imhotep's Lab Interactive FAQ

Why are all battery cell voltages limited to between 1.5 and 2 volts?
A lithium cells can be 3 volts or more.

Size of the cell appears to not effect this limitation.
A single cell watch battery has about same voltage as
a much larger cell in car battery. Why?

Why can not a single cell exceed these limits?

I have no idea why this is, maybe its to do with the chemistry.

surface area is what gives the amps

I did a little research. it is possible to increase the voltage by increasing acidity in lead acid batteries.

the problem is that the acid will dissolve the plates making it a use once and throw away battery. so it is the chemistry.

"so it is the chemistry", well, if you want a bigger bang
you add more gun power to your chemistry mix ..

More would/should create more, but isn't creating more.
More surface area for chemistry reaction isn't creating more voltage. A 3 foot battery or a 1/4 inch battery are the same voltage.. And I'm wondering why?

Say you are using a non-acid based battery ..
you are still limited.

One would think more would create more, but it doesn't.

Hi. I could be completely wrong here...
I think cell volts are based on plate material potential difference, per the
"Electromotive Series
The electrode potential of a material according to decreasing tendency to release electrons with hydrogen as zero."
So, the plate size shouldn't affect voltage. For example, aluminum is a +1.67v on the chart and copper -.47v, so cell voltage with these two materials should yield about 2v if I remember this correctly... again, I could be wrong.
p.s. these principles also work without electrolyte, if the metals are in tight physical contact, from what I've read.

bigsupersquid and mbrownn,
ah, it seems you are both right.
I've used that chart before.
I hated chemistry, so it stands to reason I wouldn't want the answer to be that one ... grumble.

Electromotive Series
http://www.diracdelta.co.uk/science/sou ... ource.html

I still don't like it one bit though !!!

If remember right, Silver and iron give a 7 volt differential.
That is from the Electrinium Battery video. Other charts of the same values
are likely found under something called "Valence" values.

CHART

Electromotive Series
Aluminium 1.67 V
Antimony -0.1 V
Arsenic -0.3 V
Barium 2.9 V
Beryllium 1.7 V
Bismuth -0.226 V
Brass -0.47 V
Bromine -1.06 V
Bronze -0.47 V
Cadmium 0.4 V
Caesium 3.02 V
Calcium 2.87 V
Chlorine -1.36 V
Chromium 0.71 V
Cobalt 0.28 V
Copper -0.47 V
Fluorine -3.03 V
Gallium 0.5 V
Gold -1.42 V
Hydrogen 0 V
Indium 0.336 V
Iodine -0.53 V
Iron 0.44 V
Lanthanum 2.37 V
Lead 0.13 V
Lithium 3.02 V
Magnesium 2.4 V
Manganese 1.05 V
Mercury Hg -0.85 V
Monel -0.47 V
Nickel 0.25 V
Oxygen -0.397 V
Palladium -0.83 V
Platinum -1.2 V
Polonium -0.4 V
Potassium 2.92 V
Rubidium 2.99 V
Silicon -0.26 V
Silver -0.8 V
Sodium 2.71 V
Stainless Steel -0.09 V
Steel 0.45 V
Strontium 2.89 V
Sulphur 0.51 V
Tellurium 0.827 V
Thallium 0.33 V
Tin 0.14 V
Uranium 1.4 V
Water -1.23 V
Zinc 0.76 V