Toyota's chief scientist explains why maximum EV range isn't necessarily the best idea

While the auto industry loves to wow us with vast leaps in electric car range, Toyota's chief scientist thinks that's a one-note tune. In fact, he says, paying for more range than you need could be unnecessarily expensive and bad for the planet. 

"Carrying around a battery that you're not (fully) using isn't an environmentally positive thing to do," says Gill Pratt, Chief Scientist at Toyota Motor Corporation. He points out that a long-range battery not only weighs a lot but continues to weigh that much when discharged or when barely being used. "If you buy a car with a 400-mile range but each day only travel 40 miles and then plug in at night, 90% of the battery in your car is being hauled around for no purpose." A long-range battery is also an expensive component. 

Instead, he favors smaller, "right-sized" batteries combined with ubiquitous charging to create range in harmony, allowing for a lighter car that achieves sufficient range from a smaller battery in a virtuous circle.

As with its position on vehicle autonomy, Toyota is something of a centrist when it comes to vehicle electrification, in spite of arguably doing the most to popularize electrification with the hybrid Prius line. "We all tend to latch on to whatever the newest thing is", says Pratt, "(but) we're going to see other types of vehicles in the future" for people who aren't near sufficient charging infrastructure or who hang on to their car for 12 years or more. 

There's currently a need for easy charging in most of the world outside of China, western Europe and Japan, not to mention vast sections of the US. Cars with combustion engines will still dominate Toyota's enormous output when it achieves its recently upscaled goal of selling 3.5 million electric cars per year by 2030.

Toyota announced the billion-dollar founding of its research institute in 2015 and soon afterward declared itself to be in the mobility business, before the "M word" was on every automaker's lips. Predictably for a company based in aging, shrinking Japan, Toyota's mobility vision is focused on the needs of people as they age. "Our focus in the robotics field is to help with aging societies," says Pratt. "In the same way that a car amplifies a person ... robotic technology can help people amplify themselves as they grow older." 

The main focus of Toyota Research Institute's headquarters in Silicon Valley is robotics. Pratt thinks that will increasingly merge with the company's dual vision of autonomy, Guardian driver assistance and Chauffeur full autonomy. In the long term, that merger may kick off another virtuous cycle: Driver assists might reduce accidents enough that cars can be safely made much lighter, amplifying the benefits of any electric strategy. "We can make the quality of life of people of any age and any ability much, much better."

Hear all of Gill Pratt's conversation with CNET's Brian Cooley in the video.