We own a 2016 and with 113,000km on the odometer it is due for a new battery. We currently get 54km/charge.
We have seen a linear degradation from day 1. We had a small bump in range when the dealer did a software update that pretty much eliminated the upper buffer on the battery. Once we had no buffer the degradation continued on its merry march to the 35% it has now.
FYI We do about 60% highway travel at around 105km/h. We live in Ontario Canada which has cold winters and hot summers. We charged to 100% about 95% of the time and we scheduled that to finish 1hr before we drove to work. We would leave the car at 80% or less if not being driven for a day (scheduled for 80% charge on Sundays). Our car has NEVER had a fast charger hooked up to it. We charge 99% of the time at home on a Eaton level 2 charge. We drive about 50% of the time in "B" mode.
Trade in value as of two days ago is $10,000, meaning the car cost us $35,000 for 5 years of ownership (fuel savings aside).
With the new battery we will rarely charge to 100%.
We will keep our speed at or below 105km/h on highway.
We will NOT use "B" mode much, especially on highway off ramps (dealer tech tip)
We will not use a rapid charger.
If we ever do this again we will lease. It makes absolutely no sense to buy an EV. ALL batteries die eventually and cost a freakin' fortune to replace.