The interviewer stated that it can take as long as 12 to 15 hours to charge at a public charging station. This could be the case for a Level 1 charger charging at 120 volts, but all chargers (such as the ones being discussed in the interview) are at least a Level 2 charger and these can take as little as a couple of hours to fully charge a car depending on what type of on board charger the car has (3.3 vs. 6.6.) and how depleted the batteries were when charging began. Most often, public chargers are utilized to top off or add some extra mileage. They are typically not utilized for charging a completely depleted battery to a full charge.