loss of range

When I got my 2014 i3,it routinely showed 100 to 103 miles of range after charging , but I have been experiencing a fairly steep loss of range for a few months now.Yesterday it only charged to 73 miles.That's a thirty percent loss in 6 months.I asked the dealer about it ,but was told everything checked OK. I am worried about the batteries,or maybe the onboard charging system. Have others experienced similar,and what was the cause?

How far has your car been driven?

Has your actual range decreased? The calculated range is only an estimate.

Has your i3's system software been updated during the time when the range estimates have been decreasing? Various software updates have changed the range calculating algorithm.

What is your average driving efficiency? The usable capacity of the battery pack when new was ~18.8 kWh. If, for example, your average driving efficiency is 4.0 mi/kWh, then your full range from full to empty would be 18.8 x 4.0 = 75 miles.

There have been very few reports of significantly degraded i3 battery packs.

My 2014 BEV states between 50-90 miles when fully charged every morning. For me, I find that if I drive the car harder the estimate mileage will drop hard. Since this is an estimate that uses the driving style, last trips and the battery, I do not put much thought into using it.

The estimated range is a sliding average of your last 18-miles or so. You can think of it in the same manner as the miles-to-empty display you may have on an ICE...it is only accurate based on what you are doing now AND that you continue to do it in the future. IOW, it is a guess. How you drive the car, the temperature, the mode, where you're driving, all play into calculating the estimate, and that's all it is. People that have lots of miles on their vehicle have reported only a minor degradation of the battery pack. Also, when new, people tend to drive it more carefully (unless showing off for friends!), but as they become more familiar with the car, it's easy to use more and more of the performance available because it is there. There is a way to determine the actual capacity of the battery pack, and the dealer likely checked that, indicating that it was within normal range. Also note, I've often gotten into the car where it said 73-miles or so, driven 10, and it indicated the same or more miles to empty...it all depends on how you drive it and where...the calculation gets adjusted. As was said, though, that algorithm has been tweaked with the successive upgrades to more closely reflect reality as more and more real-time data is obtained.

Thanks for your response.Could be my concerns were ill founded.