After the most recent battery software install, a full charge on my Kona electric report under ECO mode is 260 miles. Before the undated software installation a full charge in normal mode was always in the above 275 miles. Is there a reason for this reduction?
Your efficiency history has been reset. The GOM should come around after it's got something to work with.
GOM = Guess-O-Meter Since your range fluctuates so much in an electric vehicle, your maximum range is a 'guess' based on your prior driving history.....being your average miles/kWh. The higher your average miles/kWh, the greater your range. Your GOM will try to calculate that and display it to you on the cluster, so you don't have range anxiety. Notice how ICE cars doesn't have a GOM to tell you your maximum driving range depending on how full of a tank of gas you have. The GOM is added to relieve ppl of range anxiety and to warn them that they might be low on juice depending on their usual driving habit. Of course, the most accurate way to determine your maximum range is to just multiply your average miles/kWh to the SOC (state of charge....how full is your battery in %) to 64 (which is the usable capacity of the battery).
Just ignore it. 260-275 - who cares, it's a GOM! What affects you more is journey recharge planning based on weather, hills and driving habits. use a journey planner if in doubt.
If you range available seems low don't worry, because as soon as you start driving, your driving style will influence the estimate. I have driven around town for over 10 miles and returned home showing essentially the same range available as I started thanks to efficiently using regen and acceleration. The good thing about traffic lights is they help the Kona by regening anywhere from a quarter to a half mile of range at each stop.