OK, first off welcome to the Forum.
Charging costs…
Home, well that all depends on your supplier, but about the cheapest is Octopus Go, they do a 5p rate each night for 4 hours, on the Kona, that will give you around 100 miles, so 20p for 100 miles!
After that it depends on your normal rate, these tend to be 15-18p kW
Out and about, BP Pulse 50kWh chargers with a monthly subscription (£7.85 a month, or free on Motability if you can’t get a home charging point) and the cheapest at 15p kW
Then there are all the free chargers at many supermarkets etc.
Also, bare in mind that the weather makes a difference, you will get better economy in the warm and dry summer, than you will in the wet and cold winter, as will the way you drive, EV’s to work best need to be driven smoothly.
I’m driving the Kona Premium SE 64kW, so basically the same car, and no home charger. 2800 miles has cost me just under £49!
So, to your original question… Full charge at 15p a kW, and giving you a range of 280-300 miles is around £9.60
Previous Motability Cars
2006 - 2009 Skoda Superb VR6 2.0tdi
2009 - 2012 Citroen C5 2.0tdi VTR Nav
2012 - 2015 Nissan Qashqai 1.5dci tekna
2015 - 2018 Ford Kuga 2.0tdi Titanium X
2018 - 2021 BMW 220d X drive 2 Series Active Luxury
2021 - 2023 Hyundai Kona Electric Premium SE
2023 - Hyundai Kona Electric Ultimate