[Paperlaw]

Originally Posted by rockhead

I read that thread when I was wondering the same thing and was a little annoyed that there isn't a clear answer. However, at the end of the day and maybe like a number of others, I really only bought the 45e model this year for the tax credit. Getting great gas mileage and having that extra electric torque is just an added bonus.

As far as less capacity of the battery being made available in US spec vehicles, I think the warranty theory makes sense. In any event, I would actually prefer a larger retained buffer at the expense of less range if it means improved battery longevity. Based on reading I've done on optimizing battery health since purchasing a Jaguar I-Pace early this year, lithium batteries are happiest between 20-80% SOC and running them down to a very low, or charging and keeping them very high, SOC degrades them faster. The usable capacity of batteries in BEVs are almost never completely exhausted because drivers don't want to be stranded, and they are not charged to full as often because for many people they have long enough range for several days of around town driving. Whereas, PHEVs like the X5 45e are likely to be exhausted and charged to full every day, so it seems very prudent for BMW to retain larger buffers at the top and bottom to maintain battery health.