Batteries tend to be one of the main concerns about electric vehicles for two reasons. Firstly their sustainability and secondly their lifetime.
The environmental impact of a battery concerns 87% of drivers who are considering an electric vehicle. Work completed by Transport & Energy[1] shows that electric cars emit almost three times less lifecycle CO2 emissions than petrol or diesel cars. Importantly improved industrial scale battery manufacturing results in significantly lower impact values than used in early estimates.
When it comes to battery degradation many (if not all) electric cars have a warranty on the lifetime and performance of the batteries. This is commonly something like 8-10 years and 100,000 miles of use (more than a drive train warranty for a petrol or diesel car).
According to the RAC[2] maintaining the battery state of charge between 20 and 80% is best for the battery helping it to last longer.
Rapid charging is known to have an impact on battery life and it is for this reason that the manufacturers include complex battery management systems to ensure that the battery lifetime is not impacted. This is why charging speeds taper downwards towards 80% state of charge in order to preserve the lifetime of the battery. Experiments from the Idaho National Laboratory[3] showed that rapid charging on a 2012 Nissan Leaf had less than expected battery degradation impact than was originally envisaged.