Tesla’s Next EV Target: 5-Minute Charging

Tesla Motors Inc. tells MIT Technology Review it hopes to cut the time it takes to recharge one of its Model S electric sedans to as little as five minutes.

The goal refers to replenishing a battery in the car. Last week Tesla demonstrated a robotic battery swapping system that could replace a depleted Model S battery with an already-charged unit in 90 seconds.

J.B. Straubel, the company's chief technology officer, concedes it will probably take more than a year to work out the technological hurdles for an ultra-fast charging system.

But he notes that Tesla's direct-current "Supercharger" stations are already capable of operating at 120 kW more than 12 times the level of conventional public charging stations. Tesla has said the latest version of the Supercharger system can restore full energy to a Model S battery in 20 minutes.

Technology Review notes that Tesla's existing charging system is far more powerful than Japan's 50-kW CHAdeMo DC system or the new 100-kW "Combo" AC/DC configuration approved last October by SAE International.

Straubel says the company has been able to achieve superior performance quickly because it develops all its own key components and customizes them for its own EVs. Tesla's high-power charging stations cannot be used by other electrics on the road today.

Challenges to even speedier charging include close management of battery voltage and heat, according to Straubel. He also notes that not all parts of the U.S. power grid can handle the sudden power draws required. Tesla indicated previously that it may be able to avoid such issues by equipping its Supercharger facilities with solar panels and their own storage batteries.