On a slightly related tangent: I recently purchased an electric bike and have been very happy with it. It has the looks and performance of a 1920-30s Harley or Indian motorcycle (one revs the handle bars to accelerate like on a motorcycle, but the transmission is a clutch-less manual just like a road bike).

The range with standard battery is ~40 miles (but if battery is drained, one still has pedals.) Top speed (with electric motor alone) on level ground is in excess of 35 mph. With a basket and/or saddle bags it is a reasonable grocery getter.

My online complaint with this specific bike (not applicable to other models) is too few gears, not foldable, and lack of shock absorbers on the forks (can be worked around by deflating the large motorcycle like tires.)

Note that I am sure it is also legally limited in speed and acceleration as it does not require a motorcycle license. An electric bike legally registered as a motorcycle and capable of reaching 100 kph on level surface (yet with ability to pedal for exercise or to extend range - again classical motos often had that) is an item I would like to some day own or build.

Lithium Ion batteries are truly a revolutionary invention.