It's not obviously true that the weight and bulk of the batteries necessarily means that production will be localized. After all, the input materials are just a

It's not obviously true that the weight and bulk of the batteries necessarily means that production will be localized. After all, the input materials are just as heavy and bulky if not more so before refinement. And many of those inputs are mined from only a handful of concentrated places on Earth, and so need to be shipped long distances regardless in order to disperse to where humans actually live and demand the end products. A better argument for localization might be that the dangerous and explosive nature of battery cells makes shipping the finished product longer distances more risky (and therefore more costly) than shipping the non volatile inputs long distances. So the extra cost of shipping cells drives localization of production.