Have a look at the pictures of the engine compartments. The lower picture is already ten years old. At that time one still believed that the Smart with electric motor could be presented very soon. The difference to the engine compartment of the finished Smart (see picture 2), proves that they thought it to be much simpler than it turned out to be, although it does not contain the batteries, the lay-out is far more complex.
In edition 5/2010, the magazine 'Auto Motor & Sport' tested the first Smart with lithium-ion- batteries (identical to the Tesla), the results however, were sobering:
We must however, mention at this point, that in this Smart, the newest generation of batteries are not installed. We'll have to wait and see what happens in 2012 … 03/11