an increase of ca. 57 % seems a possibility (60 Ah to 94 Ah per cell). This is going around on various forums:
As much as I'd love to see a bigger range increase, can I just remind everyone that this is the traditional car industry we're talking about? At this point in time, they're not thinking of achieving any super-density batteries in the short to medium term to catch up with Tesla (who have gone for niche, premium, high-price, geeky customer). For now, the i3's battery only needs to keep pace with what Nissan and Renault are doing, plus being sportier. This makes sense from an engineering and cost perspective.
I think the first big leap in range (ie 150-200mi all-electric) from a BMW i vehicle can be expected when the i5 (or whatever it will be named) is announced.
As far as the next 3-5 years are concerned, PHEV will see more adoption - that's where the masses will go. And: These are the vehicles that give people an idea of what electric motoring CAN look like, and I am sure most will be hooked and want more. I mean, look at all these folks in their Outlander PHEVs, desperate to recharge their small batteries to get another 20mi fully electric. THIS is the segment the manufacturers will focus on, because it means big unit sales and low battery costs.