I have got Kona EV 2019. In severe winter the range is around 250km on a full charge vs 370km in summer.
This morning the range was 270km at 80% charge.
After 18 months I have got 105,000km on odometer. I think the battery is degrading more than 10% a year.
I was in the dealership to have the battery checked. Nothing found.
I would welcome experience and thoughts from other owner of Kona EVs.
I’ve read your previous posts as well as this one, and I don’t think for a second that your Kona has any degradation at all.
It sounds like you have used the car extensively for demanding commuting from new, without any extended period of typical urban driving i.e. several weeks. It takes that long for the car to adjust to an economical pattern. Instead it has spent its life at highway speeds, mostly with heating or cooling, so the numbers it gives always reflect that load, which is heavy. Your winter conditions require snow tires no doubt, which also significantly kill your economy. In short, you haven’t given your car a chance to show how economical it can be, so you can’t make any comparisons.
In case you don’t know, EV’s battery limitations mean they react much more to adverse environmental conditions than ICE cars do. In addition, ICE’s have a power curve which makes them most efficient on the highway but slugs in town - EV’s are the opposite.
On a recent winter trip here, the first leg of 180km used 43% SoC. The second leg was 120km, but climbed 700m, the temperature dropped to 4C, and there was enough of a wind to buffet the car a little - that took another 44% SoC, equivalent to about a 280km range at full charge. In your winter, that is your normal.
On the SpeakEV forum, @stageshoot’s Kona has been driven further than yours in less time, motorway running and frequent QC’ing. Hyundai engineers told him there is no sign of any battery degradation at all.
EV battery degradation has been clearly linked only to repeated exposure to excessive heat, and to calendar ageing, by which is meant over many years. Additionally, the Kona capacity is nominally 64kWh, but it is widely agreed that it has been engineered to provide a minimum of 64, and is typically 66-67 at new. Any capacity display will stay at 100% until that top excess is gone, several years hence.
You don’t have battery degradation, you just have very uneconomical driving requirements, and perhaps an EV wasn’t the best choice of transport...