To "Unhappycustomer" and others like us experiencing significant range/capacity loss (and possible headaches with dealers, capacity tests and warranty claims), we should probably keep in touch. If you don't want to post your experiences on this forum, feel free to reach out to me directly in a private message and we can chat offline and/or build our own little group to communicate.
Unfortunately, my wife and I have been through this whole mess before. We had S/N 500 of the first model year of the Nissan LEAF (2011) and were at the very front of the wave of early owners seeing significant capacity loss in hot climates. After just a year of ownership (Phoenix, AZ, USA), we had lost 15% capacity. By 1.5 years of ownership, we had lost about 30%. In summary, we had to help lead the fight against Nissan by teaming up with other LEAF owners, doing several stories with the news media, contacting various advocacy groups, running our own capacity test event, etc. Nissan even took 6 of our cars to their test facility near Casa Grande, AZ for detailed analysis. Long story short, they ended up buying back our car and several others. They have since changed battery chemistry a time or two, but have yet to implement active thermal management for the LEAF battery pack to account for the extreme heat of asphalt in the desert! The newly announced Nissan Ariya EV *will* have active thermal management, and there are comments online about Nissan learning from their experience with the LEAF. But I digress...
We didn't think we'd see this issue with the i3, given that it has a more aggressive thermal management system. But here we are. Whether it's truly capacity loss or 'just' the software losing track of the battery capacity, as noted by someone earlier, we are seeing some of the same dealer/manufacturer issues we saw with Nissan. Claims of no battery issue when there is clearly capacity loss. Reluctance to give information to the owner on the state of health of the battery. Reluctance to run tests.
Here's our history:
2/9/15: Approximate date our 2014 BMW i3 was received by its first 'owner' (leased vehicle, somewhere in California)
11/4/17: Purchased by us as CPO at BMW North Scottsdale (37,000 miles)
We noticed significant range loss in 2019 and started tracking the Kappa Max value monthly. At the beginning of December 2019, we took the car to the dealer for a few warranty repairs. I also stated a concern about range/capacity and asked them to do a diagnostic/capacity test. They updated the car's software, held the car for a day or two, did the test, and documented a capacity of 72%, which aligns with the Kappa Max values I had been tracking. But when I picked up the car, sure enough, the car's projected range was consistently about 10 miles higher than it was right before the service, and the Kappa Max values were also up. The values dropped a little by March, but then the Covid apocalypse hit and we haven't been driving much, so the values have 'improved' even more.
Date / Calculated Capacity / Kappa Max Value / Mileage
6/14/19 77% 14.5 55147
7/30/19 76% 14.3 55937
8/29/19 75% 14.1 56761
9/18/19 75% 14.1 57256
9/29/19 74% 14.0 57609
10/28/19 73% 13.8 58570
11/27/19 73% 13.7 59653
12/5/19 79% 14.9 59819
12/28/19 81% 15.2 60503
1/28/20 81% 15.2 61608
2/28/20 80% 15.1 62347
3/28/20 80% 15.0 62347
4/28/20 81% 15.2 63374
5/28/20 84% 15.8 63679
6/24/20 82% 15.4 63934
I'm rather concerned about these anecdotes about BMW being rather tight-lipped about battery health and the company reluctance to run diagnostic tests and warranty batteries. Again, please reach out to me privately if you are experiencing range/capacity loss and do not feel comfortable posting publicly. Much like our very long, stressful fight with Nissan, this may require some teamwork to figure out the way to make resolving these issues as painless as possible.