The German Professor Johann Tomforde made his first drawings back in 1969, that's why the smart EV is now already available in it's fourth generation. Here I've collected them all so you can easily check them out.
The smart ED4 (fortwo & forfour)
Model series 453; build 2017 - today
The smart ED4 is based on the smart of the 453 series and was marketed from 2017 until mid-2018 as ED. Since mid-2018 he joined Daimler's EQ family and is now referred to as smartEQfortwo, or respectively as smartEQforfour.
Technically, nothing changed with the switch. Technically it's based on the Renault Zoe, just the battery is still supplied by the Daimler subsidiary Accumotive. Of course, it still is very reliable.
The smart ED3
Model series 451 facelift; build 2012 - 2016
The smart ED3 is based on the smart 451 and was sold from 2012 to 2016. It's looking quiet similar to the smart ED2. However the ED3 has, except the lookes, not much in common with its predecessor.
The high-voltage technology was put together especially for the ED3 and the focus was clearly on reliability. Costs did not matter much. The high-voltage components are from Brusa, Bosch and the Daimler subsidiary Accumotive, that's why it is considered to be the most reliable smart ED so far.
The smart ED2
Model series 451 prefacelift; build 2009 - 2012
His predecessor was already outdated when they tested it in London, so Daimler got it touch with Tesla. Elon Musk later claimed that this deal saved Tesla going go bankrupt.
Tesla supplied the charger and the HV battery which was made out of their typical cylindrical cells.
The smart ED2 was only available as leasing car and as rental car provided by Car2Go.
The smart ED1
Model series 450 facelift; 2007 Test fleet in London
he smart ED1 was based on the smart car prototypes so the tech was still as it where in 1998.
The test fleet in London had a battery provided by Zytek Automotive which needed to be heated all the time at >300°C, to not only function, but also to not get damaged.