Returning to Oakland from SF with ~20 miles on the battery on March 25, 2015. When I first turned on the car, car suggested turning off radio to conserve power. I agreed, and drove back home without the radio on. At some point during the trip home, the car showed a message “charge soon.”

At 1.7 miles from my home with 7 miles still available per the dashboard, the car showed the message “PROPULSION POWER IS REDUCED”. I was on the freeway going about 60 mph, and almost immediately, the car went from 60 to 30 to 0 mph with my foot hard on the accelerator. I had time to turn on my hazard lights, cross 3 lanes of traffic and was headed towards an exit ramp when IT COMPLETELY STOPPED. Although the car appeared to still have power, the car would not move and I was unable to get OFF THE FREEWAY. This was around 12:30am (March 26 now).

Side note: On Star was unable to find me someone who would tow me off the highway for over 1.5 hours! Police had to call a traffic stop and pushed me off the freeway into a gas station.

At some point while I was on hold with On Star, I noticed that the Brake System Warning light (on the right side of the dashboard) was on. It had not been on while I was driving. While I was waiting at the gas station, the message “Unable to charge” showed up. The car was towed to my home - and yes, the car refused to charge.

Car was towed to dealership, where they found out that a battery cell had gone "bad" and needed to be replaced. Both before and afterward, the car has worked perfectly.

This was a very dangerous situation. If the road had been busy, I'm sure I would have been rear-ended.

Overall, we are very pleased with the car and continue to drive it, but think others should know about this problem.