Very interesting, I did not know selling the batteries was part of the plan. Are the trying to remain independent though or would they be a very large acquisition target long term then? I suppose they could license out large format battery tech to a number of other industries as well?
Selling batteries might be a bit of a misnomer since they'll probably be working with their existing partners (Toyota[1] and Mercedes[2] primarily) who would both presumably invest in the battery facility too.
The 500k cars worth of batteries would probably be some combination of Teslas, Toyotas, and Mercs. Since the latter two companies have already invested in Tesla, and have working partnerships, they would probably get the batteries for the same price as the Tesla internal transfer pricing. (Mostly speculation on my part) It then wouldn't be a profit center for Tesla as much as it would leverage the scale of a bigger facility to lower tech costs for all three companies.
