All electric vehicles and plug in hybrids are charged by connecting them to a charging station. Charging time depends on the size of the battery pack and the power source for the charging station. For example, the Chevrolet Volt Plug In Hybrid takes about 10 hours to charge with a 120 volt charging station but takes 4 hours to charge with a 240 volt charging station.
Fortunately the industry has gotten smart about these charging stations. They have created the SAE J1772 standard. This standardizes the charging stations used with electric vehicles. For example the Chevrolet Volt and Nissan Leaf can be charged using the same charging station. It is safe to assume that future electric vehicles will use this same standardized charging station. This is crucial when they start placing public charging stations in public parking areas. You will park near what looks similar to a parking meter, connect your car, swipe a credit card, and your vehicle is charged while you are parked.
Battery power is by Lithium Ion batteries similar to what are used in laptop computers, cell phones, cordless power tools, etc. Just on a much larger scale. Final output voltage of the battery pack would depend on the individual vehicle.