Steve that beef pulse on the cell could be due to 2 things...
one: the plates attracts charges and neutralizes when disconnected
two: there might be a certain measurable inductive phenomena in the cell.
I think that the force bounces a little bit back, like an inductor.
However, only just the layers of ions on the plates.
The rest of the charge is in the waterbath.
Compare it with a capacitor that does not discharge in totall.
If you would be able to build a circuit that catches the bemf pulse in a coil, like a buck converter, you might step up voltage....