Have been curious about what state of charge (SOC) to keep my Niro EV at. Was thinking that fully charged would be best, but maybe not so. Found the following link you may be interested in if you've been thinking about this as well:https://www.plugincars.com/eight-tips-extend-battery-life-your-electric-car-107938.html
The Niro EV is our second EV. We have always strived to keep the 17 Leaf between 20 and 80% (we have on occasion had to charge more for a trip or ran lower than 20% before we made it to a charger). We plan to do similarly with the Niro as well.