Range Anxiety + Charging Infrastructure

2/28/2015 - Understanding Range Anxiety

BMW i3 To better understanding the feeling of range anxiety that our users face, David and Sherman took a drive to Fremont with an i3 to experience the feeling of having less than 10 miles worth of charge left before returning to our original destination.
Starting with 70 miles of charge, we used GoogleMaps to ensure that the round trip mileage would leave us with a 15 mile buffer of charge make it back on campus.
When we were considering a third destination in the middle of our trip, we were forced to conduct a rough estimation of the extra mileage we would use up in the loop and justified the decision to make the extra stop by calculating that there would be at least 7 miles left.
Upon the return trip, we arrived back on campus with less than 5 miles of charge left - an indication that we had underestimated in our calculations. The trip taught us that range anxiety is a persistent feeling that lasts throughout a newfound trip where the drivers are unsure of the total mileage needed.

3/1/2015 - Understanding Mobile Charging Infrastructure

group panoramic photo As a group, we took a trip to the top of the Skyline trail in Redwood City to assess the ability of the electric car to respond to a sharp increasing gradient. During this excursion we learned several things:
1. Sufficient charge is generated during the downward slope to increase the range of the car that it started with at the top of an incline.
2. Driving uphill clearly expended the car's charge.
3. Using the "ConnectedDrive" feature of the BMW required the iPhone to be on with the application in-use in the foreground:
Pandora + BMW

Upon exhausting the majority of the charge energy, we used the fast-charging station to better understand the mobile infrastructure surrounding charging:
Mobile interface

Though the mobile application could start and stop charging the car remotely, we struggled a bit to discover the order of plugging in and then starting the charging process through the application. The mobile interface also failed to synchronize with the station's display (as shown in the screenshot taken above).

Conclusion

These experiences validated the pain point of charging for eCar owners, and gave us a deeper and personal understanding of range anxiety and the charging experience. We realized quickly the necessity of having to charge the car daily even after using it for just a weekend.