@TimG - if costs continue to fall, wouldn't that be a factor?
It will be very hard - if not impossible - for the cost of EV including battery to be much less than an ICE. The best that can be hoped for is cost parity. Convenience will be an important factor: especially once EV reach a point where queues at charging stations become unbearable. The longer charging time compared to ICE means fewer vehicles can be serviced per hour given the space available at a gas/charging station. This problem will be aggravated because the need to build out grids mean it is not enough to expand charging throughput by just building a new station - getting the permits to upgrade the grid and/or build the power stations needed to provide the power on demand (read: fossil fuel) will mean huge lead times. In the meantime, hellish wait times for the EV driver while the ICE drivers laugh at them after spending 5 mins refueling.