The SR model comes standard with an 11.4 kWh lithium-ion battery pack, while ours was equipped with the optional Power Tank ($2,495) that adds another 2.8 kWh. With the standard three-prong cord plugged into a conventional 110-volt wall outlet, a full charge typically takes around 10 hours. Speeding up this process is pricey. Zero’s quick-charge unit ($599.99), when paired with the integrated unit, cuts the time in half, while upgrading to a CHAdeMO plug (as found on many electric cars) can cut that to an hour and a half total. That accessory, however, will set you back another $1,799.99, and charging stations are still few and far between.