I recently passed a new factory which was not working yet. I asked what it was for and was told it is a new joint venture between Mercedes-Benz and BMW to make batteries for their new range (unannounced as yet) of electric cars. What is different is that these batteries will always remain the property of the manufacturer and will be placed all around Europe at service stations where the customer will just change his battery for nominal cost just like refuelling and take no more than 3 minutes to actually change. The idea is to keep the initial cost of the vehicle down seems like a good commercial idea. The factory is in Grossrohrsdorf Sachsen, not far east of Dresden.