In my experience people often refer to those scooters generically as "vespas", even if it's not strictly accurate. So while no scooter manufacturer would condo

In my experience people often refer to those scooters generically as "vespas", even if it's not strictly accurate. So while no scooter manufacturer would condone the generic use, "electric vespa" might get across what you mean? Of course then you're stuck talking about Vespa vespas and non-Vespa vespas...