A key design parameter of the Chevrolet Volt was a target of for the all-electric range, selected to keep the battery size small and lower costs, and mainly because research showed that 78% of daily commuters in the U.S. travel or less. This target range would allow most travel to be accomplished electrically driven and the assumption was made that charging will take place at home overnight. This requirement translated using a lithium-ion battery pack with an energy storage capacity of 16 considering that the battery would be used until the state of charge (SOC) of the battery reached 30%.