Of course, not. That would be silly. The Volt is an arbitrary unit. After the revolution, we'd be using natural units. https://en.wikipedia.org/wiki/Natural_units

Basically, you'd express things in terms of speed of light, electron charge, planck length etc.

In this case, [Planck energy / electron charge] might be an appropriate unit.

(It would also be a pretty useless unit, because it's absurdly large compared to everyday voltages.)

See also https://en.wikipedia.org/wiki/Planck_units

Pretty sure that David Graber demonstrated that there have been societies which used Natural units.

Ancient Egypt apparently used something very similar to the meter.

128V ftw.

And for an upper limit: 18000V / 137 = 131.4V