Bjørn Nyland recently once again tested the battery capacity of its Tesla Model 3 Performance, which previously lost 6% within 14 months and about 60,000 km (37,300 miles).
As it turns out, after close to two years (22 months) and 80,000 km (50,000 miles), the battery degradation progressed further to about 8%, compared to new.
It's quite a substantial decrease, but in Bjørn 's case, the car was driving a lot and also fast-charged a lot:
- DC charging total: 11,813 kWh (60%)
- AC charging total: 7,995 kWh (40%)
- Total: 19,808 kWh
During the test, Bjørn estimated that the total available energy at 67.0 kWh (compared to 71.4 kWh nominal, indicated by the car, including about 3.2 kWh buffer. When new, the car had 73 kWh.
The latest and previous results of total battery output (energy available) are as follows:
- April 27, 2019: 73 kWh
- October 15, 2019: 69.6 kWh (-2 kWh by software?)
- June 13, 2020: 68.8 kWh (6% degradation)
- February 6, 2021: 67.0 kWh (8% degradation)
Bjørn explains also that the cold temperature (-13°C) might affect the test result, however, probably not that much. Maybe it would be a 7% or 7.5% loss.
Anyway, at this point, it seems that the battery degradation is going down by 1% per 10,000 km (6,200 miles) and 1% per 11 weeks. If nothing changes, 80% of the initial capacity (20% degradation) should be reached at 200,000 km (124,300 miles) or within 5 years, but that is only an extrapolation.