Just got a 120Ah battery replaced under warranty
An i3s made in October 2019 did not want to get charged anymore. Brought it to a dealership on 2/4 with an almost depleted HV battery. They first pointed out that the 12V battery was dying (apparently it was still an original one that lasted 75k miles) but eventually agreed that the HV battery needs to be inspected. Of course they wanted almost $3k just to drop the battery and test the cells, which I had approved. They gave me a new i4 as a loaner. By 2/17 they got an approval from Germany to replace everything under warranty. Before that they thought that maybe only a faulty cell, that they found, can be replaced. The car was ready by 4/15, so it takes almost two months to get the parts delivered to California. There was zero arguing or excuses, just brief professional communications with a manager.
In the meantime the 12V battery died completely, and they could not start the car. I refused a $600 replacement charge, ordered a $130 Energizer battery from Amazon, received it next morning (it arrived fully charged) and came to the dealership. They let me in to the parking lot to replace it myself and then I was gone. $0 out of pocket, invoice attached.
For the last three years the car was driven >70 miles a workday, and DC fast charged from ~50% to 100%. Frequently driven with the gas pedal on the floor, so one may say the battery had a difficult life. The battery was degrading over the last year or so, the battery capacity was around 33kWh last time I checked before it died.
I have yet to see how the new battery is doing. When I picked the car it was only charged to ~90%, and the first 100 miles got it depleted to 25%. So I was not very impressed. I am slowly charging it at L2 while typing, maybe the first balancing will improve it.
Since the invoice shows all zeros, I only got a comment from the manager: $55k invoiced to OEM, and for a customer it would have been $60k. I have no means to verify that, but it seems to agree with a recent Recharged article estimate.