The problems with electric cars have always been the same: volumetric power density, battery longevity, battery cost, charge time.
Today most of these issues are largely resolved and close to being non-issues. The next generation battery technology is likely to place electric storage ahead of gasoline in terms of power per unit volume.
The next challenge to electric vehicles is safety. Before electrics can reach penetrations in the range of millions of units in major markets they'll have to prove they are safe in such concentrations.
Imagine how much further forward EV tech would be if this had actually been mass produced back in the 70s.
Electric cars were always unpopular with big auto manufacturers and the oils producers and that probably never allowed them to grow up alongside their smell cousins. Just looking at this little car imagine where we would be if it had started a real push in the 1970s.
Once upon a time there was more electric vehicles in New York than petrol powered ones, it seems like every couple of decades people really have a crack at the issue of an electric car: http://jalopnik.com/5870808/how-a-new-york-taxi-company-kill...