The time taken form start to finish is about an hour due to the simplicity of the circuit. I did perform some test to determine the voltage output from the piezoelectric elements and it was able to produce 1.5V and above depending on how hard the I pressed the piezo. Also I tap the piezoelectric elements couple of time and I was quite shocked to see a voltage output as large as 8.5V. The faster I tap, the higher and stable the voltage output become. I did notice that the voltage output tend to hovers around 4V to 5V.