Using tin can increase the energy storage capacity of a battery cell by nearly three times, he said.

FORBES: Tin: The Secret To Improving Lithium-Ion Battery Life

The CrossBlue's lithium-ion battery has an energy capacity of 9.8 kWh and is housed in the center tunnel.

ENGADGET: VW unveils CrossBlue plug-in SUV with iPad mini headrests and 85MPGe efficiency (eyes-on)

The Turbo battery has 342 Watt-hours of real capacity, meaning that all of this energy can actually be used by the rider instead of some theoretically possible calculated number.

ENGADGET: Specialized Turbo e-bike reaches the US, offers a speed boost for $5,900