Over time, the capacity of a battery diminishes. Just how fast depends on a number of factors, including battery chemistry (& there are an enormous number of variations, big & small), operating temperature, levels of maximum & minimum charge, & charge rate.
Its early days for LiIon batteries in automotive applications & nobody has all of the answers. One expression of this is the ultra-conservative approach General Motors has taken with battery mangement in the Volt: in the every first Volts, a "fully charged" battery was actually 80% of capacity, & a "flat" battery was actually 20% of capacity. I.e., only the middle 60% of battery capacity was used, with obvious negative effect on battery range.
Purpose was to extend battery service life. Reduced range is acceptable in the Volt, as the internal combustion engine+generator range extender allows unlimited range.
With relatively small changes in battery chemistry, GM has increased the useable capacity of the battery to 65%, & electric range by a few kilometers, in more recent Volts.
Tesla manipulates charge levels for battery durability in the Model S, by allowing two levels of charge: one for commuting & a slightly higher level when maximum range is required.
For electric vehicles (EVs) without a range extender, quick charging is virtually essential when operating beyond maximum battery range, or even close to. Downside of quick charging has been concern about its effect on battery life. Little hard data has been available. Now, the Idaho National Laboratory is running trials with 4 Nissan Leaf EVs:
http://www.greencarreports.com/news/1090954_does-quick-charging-hurt-battery-life-total-miles-are-more-important / EV electric vehicle car makers Nissan Leaf recommend recommendations owners charge frequency frequently using quick-charging stations chemical processes rapid rapidly charging cell battery degrade faster regular charges reduce reduction reducing range recharge experiment Phoenix Arizona overall mileage Idaho National Laboratory Simanaitis Says evaluate evaluation evaluating electric cars Level 2 220 Volt 40 Amp recharging DC quick charge 80 percent capacity 30 minutes climate control results lost capacity fast charging degraded fast charged winter high summer temperatures report driving /
