Because time is precious, fully electric cars are unlikely to become the primary vehicles for most households until they can be recharged in the time it takes to fuel up a conventional vehicle at a service station. While fast-charging stations are one approach to get there?and that technology is advancing rapidly?there is one other way to do it: battery swapping. A patent filing posted in September suggests that Tesla, despite the rapid expansion of its Supercharger fast-charging network, is still considering that option, too.
Before Tesla tested battery swapping, a startup called Better Place attempted to build a subscription-based battery-swapping business model that some likened to buying air time for a cellphone. Using a proprietary system, the company could swap out a nearly dead battery for a fresh one in just a couple of minutes. Better Place was well backed, but it failed when it couldn?t afford the massive upfront infrastructure costs of its own scheme. Tesla designed its Model S to be compatible with a similar battery-swap system?boasting a fresh, fully charged battery in as little as 90 seconds?and in 2014 established a limited pilot program using a test station at Harris Ranch, California, the site of a busy Supercharger station and effectively at the midpoint between Los Angeles and the Bay Area. That test ceased in 2015 amid controversy over the additional California ZEV-credit revenue the company was earning for the program?although Tesla then cited a lac...