Given: a 60kwhr battery, 10k driven mi/yr, PHEV 80% electric
Using the battery in:
a) 1 BEV converts 10k miles from gas to electricity, new charging infrastructure required for road trips
b) 5 PHEV (5X12Kwhr) converts 40k (5x8k)miles from gas to electricity , no new infrastructure required for road trips
Bottom line. The US should focus on PHEV until battery become cheaper, safer, more environmentally friendly, more abundant, and longer range. A rapid conversion to PHEVs is better for customers, car manufacturers, and the environment.
Alternatively, a 200HP 50 mile BEV, with a 50HP gas range extender also works well.