By the time the low-cost Tesla is released, Supercharging might only take 5-10 minutes

Seth Weintraub | Aug 25 2013 - 10:37 am PT

In an interview with MIT Technology Review, Tesla CTO JB Straubel says that battery charging technology is going to get even quicker than it is now.

“It’s not going to happen in a year from now. It’s going to be hard. But I think we can get down to five to 10 minutes,” Straubel said in an interview with MIT Technology Review. He noted that the current superchargers, which deliver 120 kilowatts of electricity, “seemed pretty crazy even 10 years ago.” Conventional public charging stations deliver well under 10 kilowatts.

Tesla has already reduced its Supercharger times in half going from 40 minutes to 20 minutes for a half charge. A few more ‘half times over the next few years and we’ll be there. One of the barriers of this type of charging is heat so this might involve external or internal cooling for battery charging.

One challenge of fast charging is that delivering power to a battery very rapidly can cause it to overheat. To avoid damaging the battery, the outside charger needs to communicate with the electronics that monitor the state of the batteries, including their voltage and temperature, and quickly adjust charging rates accordingly. “To do that kind of charging, everything has to be designed and working in perfect synchrony,” Straubel says.

Achieving five-minute charges will require not only further improving the charging system, but also improving the interface with the electrical grid. As it is, only some places on the grid can handle 120-kilowatt charging. Drawing large amounts of power from the grid also incurs demand charges from the utility, increasing the cost of the system.

But Straubel says that Tesla plans to get around these problems by equipping supercharging stations with solar panels and batteries.

The rest of the interview is here and worth a read.