[Akutni]

I would like to ask whether I am right. The voltage of one voltaic element is 1,1 V (derived from the difference between the redox potentials of Zn and Cu). The voltages of connected voltaic elements add so the voltage of a voltaic pile made of 20 voltaic elements is 22 V.

[Borek]

The voltages of connected voltaic elements add

Generally speaking the final voltage of connected cells depends on whether the cells are connected in series or in parallel.

But in this particular case you are right - voltaic pile has them in series, so the voltages sum up.