Tesla Motors, as part of its collaboration with Mercedes-Benz, built electric powertrain components for the E-Cell. The 36 kWh battery contains approximately 4,000 individual lithium-ion cells. Mercedes has developed a modular system for electric vehicles with battery and fuel-cell. This system allows the efficient use of shared parts in all the brand's electric vehicles. Thanks to the modular approach the electric drive of the A‑Class E‑Cell is also used in the B‑Class F‑Cell, and the energy storage units in the A‑Class EV are the same as the battery in the Smart fortwo electric drive.