I'm sure it depends on market, but I also know 100% that if they will certify the battery as safe, and then you get electrocuted when entering your car because the battery was not safe - they will be on the hook, in all developed markets. No one else, that cares about people safety, do the same thing for under $100. Even Tesla, that almost completely disregards any safety - be it "Full Self Driving" or "let's just change this, without checking if the battery is actually safe", does not do it under $100.

Given that I've tried to hold BMW to their warranty and was shafted I would not bet on that.