While consumers are accustomed to their laptops and phones losing capacity over time, those batteries are relatively inexpensive compared to a car and easy to replace (unless you have an iPhone, iPad or a Macbook Air). Loss of battery capacity is also more of an annoyance on these devices compared to the loss of driving range in a car which can leave someone stranded.

Nissan opted to go with air-cooling for its battery which reduces the weight and cost, but will inevitably have a cost in longevity. We haven't heard of any similar issues yet with the liquid-cooled battery in the +Chevrolet Volt but it may not be as noticeable in this range-extended machine. The +Ford Motor Company Focus Electric hasn't been on the road long enough and there aren't enough out there to see if this will be a problem with its liquid cooled pack. 

Average consumers are used to driving their cars for years on end without losing significant functionality. If plug-in vehicles continue to exhibit this sort of degradation, it certainly won't do the effort to electrify transportation any good.