Editor’s Note: EarthTechling is proud to repost this article courtesy of Txchnologist. Author credit goes to Jim Motavalli.
Who says that electric cars have to be held to 100-mile range? Consider that the Tesla Model S, due in June, will have switchable batteries. And consider that Tesla is offering a range of packs for that car, with 160 to 300 miles of range. Now add in that Better Place is poised to bring its automated five-minute battery switching to select audiences around the world, in Israel, Denmark, Australia, Holland, China and the U.S., with Hawaii and San Francisco first. Add this up and a potential scenario emerges —100-mile batteries for quick charging and commuting, and longer-range alternatives switched in temporarily for that fabled trip to grandma’s house. (Tesla could take this route, but right now it’s betting on powering through with big packs.)
CEO Shai Agassi told me in Israel earlier this month that this vision is Better Place’s business model. “The 300-mile, 100-kilowatt-hour battery fits into the same space [as a smaller one]. Instead of paying a ton more for a [long-range] battery, you can get one temporarily installed at a swap station.”
Agassi also offered another reason why you won’t necessarily want to own a permanently installed long-range battery, as seen in Signature Model Tesla Model S cars. You’d need two megawatts of power, akin to the Empire State Building, to quick charge that battery,” he said.
Agassi’s argument is that battery technology improves 8-10 percent a year, so why buy what could quickly become yesterday’s technology? That worry—being stuck with an expensive, boat-anchor battery—has given pause to some would-be early adopters. Instead, Better Place’s model calls for battery leases, which would make it fairly easy to swap in cutting-edge packs (and alleviate anxiety over the quality of the battery in your car since you would never own it.)
Tesla: Long range but no swapping
Tesla CEO Elon Musk gets this on some level. Last year, he opined, “When people take an occasional two-way long distance trip, they’ll get a replacement pack and then pick up their original one on the way back. The issue of giving up your one-year old pack for a three-year old one goes away.”
These days, however, Tesla is de-emphasizing swapping in favor of fast recharging. The company has no plans to either rent or lease batteries, and isn’t building swap stations. According to Shanna Hendriks, Tesla’s communications manager, “Elon said that about battery swapping a while ago, and as a company we’re more focused on the ‘superchargers’ (480-volt)” at some point in the future.*
Hendriks said Tesla’s supercharger will be able to get one of Tesla’s 85-kilowatt-hour packs to a 50 percent state of charge in 30 minutes. The packs sit flat on the floor and can be quickly removed, but Hendriks said that feature is designed more to make them easily serviceable than swappable.
Tesla tells customers, “While technically possible to upgrade from a 40 kilowatt-hour battery to a larger battery at a later time, Tesla recommends configuring your Model S with the battery that meets both present and future needs.”
Beyond onboard batteries
There are other ideas for extending the range of EVs. Aftermarket supplier Rinspeed has fielded a concept called “Dock+Go” that was shown at the 2012 Geneva Motor Show in March. The idea is to increase the utility of city cars like the electric Smart car by adding a modular third-axle “backpack on wheels.”
The attachment (which can come in a variety of extra-space configurations to serve everything from pizza delivery to camping) can be stacked with additional batteries for greater range, or it could contain a small gasoline engine to turn the car into a Volt-like plug-in hybrid. Yet another approach is to have the third set of turning wheels act as a generator to recharge the car’s existing pack, greatly extending its range.
Phil Sadow, who famously hacked Nissan Leaf’s standard 120-volt charging cable so it recharges at double speed from a 240-volt outlet, refuses to accept that electric cars have to be limited by the range of their onboard batteries. His latest innovation is a propane-powered Capstone turbine that can be hauled behind the Leaf on a small trailer. The turbine, turning at 100,000 rpm, can generate something like 30 kilowatts to keep the car on the road as long as it has fuel. I would expect any towable turbine to be quite expensive, which would limit its marketability to EV owners who already paid a lot for their cars.
We may look back at these makeshift devices with amusement, because a variety of companies say they are working on fast-charging packs with as much as 500 miles of range that would make range extending moot.
* This sentence was edited to reflect the indeterminate timing of SuperCharger station launch.