SparkCharge units feature a stackable battery system to extend range. Up to five batteries can be stacked at one time, delivering up to a maximum of 75 miles with all five, or 15 miles per unit. The charge is delivered at a rate of approximately 1 mile every 60 seconds. This is 14x faster than level one, and 6x faster than level 2 charging, placing it in level 3 territory. The units are small and lightweight allowing them to be easily transported in the trunk of a car and moved by hand!