Talk:Battery capacity
Actually, voltage is dependent upon the chemistry of the reactions taking place - for nickel cells, this is nominally 1.2V, alkaline chemistry produces a nominal 1.5V, silver oxide cells a nominal 1.55V, Nickel-zinc cells a nominal 1.6V
This can be varied within quite tight limits, but the nominal voltage is intrinsic to the electrochemistry going on inside the cell.