"Imagine that for a second. Take all of the electricity in every home, business, school, hospital, everything in your entire town….and run it through a pop can for just an instant.
The capacitor storage banks are configurable for different voltage ratings, current ratings, and discharge times when needed. This is the standard 1,800VDC configuration that it was designed for and how it is usually operated as it’s a pain to change all the bank and cell jumpers. We operate Thumper at the 1,800 volt setting, but only charge it to 1,600 volts to be as nice to the caps as we can be as this is a particularly harsh use for them”
[Source] Hacked Gadgets: Project Thumper