Battery degradation question for 2021 Kia e-Niro

[Queenbee]

I looked at a 2021 Kia e-Niro with 30,000 km, and the battery's already at 85%. Seller thinks I’ll get a new one if it drops below 70% in 3 years. Anyone have experience with battery degradation curves on these?

 

[Uly Alega87]

I looked at a 2021 Kia e-Niro with 30,000 km, and the battery's already at 85%. Seller thinks I’ll get a new one if it drops below 70% in 3 years. Anyone have experience with battery degradation curves on these?

How did you figure out how much the battery had degraded? Was it done using OBD data, a special test, or the car's own guess?

 

[Queenbee]

I checked the battery health through the car’s built-in diagnostic tool. It showed the current state of charge and degradation, but I’m curious if other methods like OBD data could provide more accurate insights.