Commuting in an electric car
When I made the decision to buy the Kona electric there was no where I could find that had extended real-world numbers. There were lots of people asking the same kind of questions as I was, so being a nerd I figured this was the perfect time to break out a spreadsheet(!).
Over the year I’ve logged 257 trips with the goal of finding out how speed and temperature affects the range of the car.
The vast majority of the trips are my work commute so they’re on the same stretch of road day-in day-out. I logged the distance, cruise-control speed setting, driving mode, AC temperature, battery used, reported efficiency, and a few weather notes. The idea being that through volume of data I can average out the effects of very bad weather or traffic to give a good, general, real-world look at how far the Kona or other EV can go.
The car
- Hyundai Kona Electric 64kWh Premium
- Single passenger + 2 carseats*
- AC preconditioning in the mornings*
- Adaptive cruise-control set
- Regenerative braking level 0*
- Running Android Auto with GPS and podcasts playing
*This is true for 90%+ of the journeys
The route
Roughly 62 miles depending on direction. Nearly all dual-carriageway (70mph limit) with 30mph sections for about 1 mile at either end. The route is punctuated by a number of roundabouts and there was generally congestion 2–8 miles long when nearing Cambridge.
Results
I calculated the maximum range in two ways:
- by taking the efficiency value e.g. 4 miles per kWh and multiplying it by 64
- by dividing the distance by the amount of battery used and multiplying by 100
The data isn’t going to be completely unbiased as I’ve made fewer 70mph trips in cold weather for example, but I’ve tried to get at least a few trips in for each variation so there is a spread for some generalisations.
When we chart the data by averaging the maximum range for a given temperature we get this:
Finally when we average the values across each month things look like this:
I don’t think there are any huge surprises there — the faster you go the lower the total range. The car mode (eco/comfort/sport) have little effect. The drop-off from 70 to 65 to 60 is small enough that I generally drive at either 70 or 60 at this point. I could travel both ways at 70 easily, however, because the electricity tariff I have is low rate for only 4 hours, the extra charging time, although small, is considerably more expensive. Travelling over 70 would be against the law :) but I would expect that the range to be more like 3.5 miles/kWh or 220 miles maximum at 80.