One of the big conflicts in battery tech right now is how to keep the things at the right temperature. Nissan and Mitsubishi are going with air cooling, while Tesla, Chevy, and as of today Ford are all opting for liquid temperature regulation. Since few electrics are really on the road, it seems there isn’t sufficient data to go with one over the other.
When batteries get really cold, they can’t hold a charge, as BMW noticed with its Mini E fleet. On the other hand, if they get too hot, cracks can develop from the swelling material and cause electrodes to fail. And of course, until you get a few thousand of your vehicle out to consumers, it’s going to be hard to get the kind of large-scale testing that’s needed.
Anyway, Ford has decided to take the safe (but more expensive) route of using a liquid temperature management system in which a circulating fluid can be heated or cooled in order to keep the batteries at optimum temperature.
Maybe this will be something hashed out in the first generation of popular electric cars, or maybe it’ll just be one of those things you see on some models but not others.