I am in the process of buying a 2015 BMW i3 from a used car dealer. It only has 18,000 miles, and so I assumed the battery pack would be close to full capacity. $13,000 plus a decent trade in on my 2009 Honda Fit seemed like a good deal. When the dealer had difficulty getting it charged up to deliver to me, I requested it be taken to BMW, who is now replacing one of the cells. With only 18,000 miles on it, the most likely circumstance I can think of is that the car sat for a long time without being charged and damaged the battery, which is somewhat plausible given the vehicle's history. The dealer openly admitted that he did not understand EVs well, and readily agreed to have BMW check it to protect him as well as me. No money has changed hands yet.
I would appreciate some guidance here. What should I expect from the battery after warranty replacement? When BMW replaces cells under warranty, do they restore full original capacity, or just get it barely over 70% and out of warranty range? After replacement, is it still under the original warranty period and mileage, or is it warrantied for a new 8 years/100,000 miles from the date of the replacement? Should I request that they check the 12V battery as well? What information should I request from BMW and the dealer to reassure me that all is OK? At what point should I renegotiate price, which I agreed to assuming that the battery capacity would be close to that of a new pack, and at what point should I walk away and look for another? Is it worth it for me to pay a different BMW shop to do an independent check for me? Are there other questions I should be asking?
Thanks for any help or advice you can provide!
P.S. I cross-posted this in the battery thread. These are my first posts here. I apologize if I violated a rule.