I've seen a few on Amazon, you can preview what's inside them for at least 10-20 pages. A local Borders or B&N would be logical too.
The big problem is the audience and the pace of technology. A book would have to be written in layman's language and leave out the complexities of battery usage or motor controllers. And a book written just a few years ago would likely dismiss LiOn or even NiMH as being too expensive (granted they are still not competitive with lead-acid) and sources to procure the equipment change wildly.
The scarcity of hybrid cars (lots of models, low production numbers though) today and the removal of the only mass-produced electric car (EV1 from GM) says a lot about the viability of the technologies on a large scale. And if you just look at the raw energy cost, electricity is more expensive than gasoline, so the efficiency is really important from a value standpoint.