The Tesla does not use AA batteries. Someone I know thinks your expert is pretty clueless. Just because an individual cell is a SIMILAR size to a AA battery does not mean the car runs on AA batteries.
From Tesla:
We started our design by purposely picking a small form factor battery cell. This cell is called
the 18650 because of its measurements of 18mm diameter by 65mm length (i.e., just a bit larger
than a AA battery). Due to its small size, the cell contains a limited amount of energy. If a failure
event occurs with this cell, the effect will be much less than that expected from a cell many times
larger. Billions of 18650 cells are made each year. Though the chance of a safety event in a
laptop is small, the number of safety incidents involving Li-ion batteries is rising each year
because there are so many more devices using small and powerful power sources.
The Tesla Roadster battery pack is comprised of about 6800 of these 18650 cells, and the entire
pack has a mass of about 450kg.
