The replacement of the battery becomes moot if the car is worth less than the battery when it comes time to replace it.  It's like deciding to put a new engine in an ten year old car without one (ask yourself who wants a ten year old EV other than the original owner given the rapid change in technology over that time).  The prices have batteries have fallen quite a bit but not enough.  The battery for the Chevy Bolt is still more than $15k.  I look forward to reading a post from you when your battery expires to see if you actually replace the battery or the entire car.  
And I haven't even discussed the environmental cost of battery disposal or recycling.   Currently, it still costs more to recycle a battery then the recovered material is worth.