When I gave my sister her first ride in the Spark EV, the battery was low and naturally we talked about range. I plugged my smartphone into the 12v USB charger I have in the car, since the phone was low as well. My sister questioned if that was a good idea since the car was so low and she didn't want us to get stranded. I was dumbfounded with her concern as the battery sizes are about three orders of magnitude different.
My sister's lack of perspective and experience with EVs is representative of the average consumer's. So here's my Public Service Announcement about charging your smartphone with your car.
First and foremost, EV batteries are HUGE compared to anything with which the average person has experience. The Spark EV has a 18,400 Wh battery. A typical smartphone battery is about 11 Wh. The Spark EV battery stores 1,700x more energy than the phone's!
How much will charging the phone reduce the EV range? Not enough to care, but we can calculate it! Assuming an hour long drive at 4 mi/Wh efficiency, the car's drivetrain will use about 15,000 Wh. A 2.4A charger in the car will fully recharge a phone during that trip using about 11 Wh, ignoring conversion losses. The phone consumes 0.07% of the EV battery. That's equivalent to less than 250 ft of driving distance.
There are a number of factors that affect EV range that drivers should consider; such as temperature, winds, elevation changes, and driving style; but phone charging is not one of them. Charging a phone for an entire trip uses far less energy than a single, mildly-spirited, 50-Wh acceleration away from a stoplight.
If you're curious, here's the USB charger I use. I like it because it's capable (dual 2.4A) and small: http://www.amazon.com/gp/product/B00M6QODH2
My sister's lack of perspective and experience with EVs is representative of the average consumer's. So here's my Public Service Announcement about charging your smartphone with your car.
First and foremost, EV batteries are HUGE compared to anything with which the average person has experience. The Spark EV has a 18,400 Wh battery. A typical smartphone battery is about 11 Wh. The Spark EV battery stores 1,700x more energy than the phone's!
How much will charging the phone reduce the EV range? Not enough to care, but we can calculate it! Assuming an hour long drive at 4 mi/Wh efficiency, the car's drivetrain will use about 15,000 Wh. A 2.4A charger in the car will fully recharge a phone during that trip using about 11 Wh, ignoring conversion losses. The phone consumes 0.07% of the EV battery. That's equivalent to less than 250 ft of driving distance.
There are a number of factors that affect EV range that drivers should consider; such as temperature, winds, elevation changes, and driving style; but phone charging is not one of them. Charging a phone for an entire trip uses far less energy than a single, mildly-spirited, 50-Wh acceleration away from a stoplight.
If you're curious, here's the USB charger I use. I like it because it's capable (dual 2.4A) and small: http://www.amazon.com/gp/product/B00M6QODH2