Cnet journalists visited the
Tesla headquarters and visited the thermal test lab, where they tested batteries for the future Tesla Model S at temperatures from -75 ° C to 50 ° C.
In the current Tesla Roadster sports car, the cells are packaged in a compact “box” that fits right behind the Lotus Elise seats (chassis, which is used for the Roadster). In Model S, we decided to use a different approach: the cells will be located along the entire bottom of the car in order to lower the center of gravity as low as possible. Tesla's chief engineer also explained that such a format contributes to torsional stiffness and security. The steel frame around the perimeter protects against deformation. In general, he believes that the Model S will occupy the first place in its class in torsional stiffness, which will positively affect the car’s handling.
The reservoir of batteries also serves as an additional protective armature, which prevents penetration into the cab during side impact.
Tesla has not yet disclosed how much the Model S battery pack will weigh, but it looks more massier than the Roadster, which has a battery weight close to 450 kg. At first glance, the dimensions of the Model S battery substrate are about 2.1 meters in length, 1.2 meters in width and 15 cm in thickness.
Like the Roadster, Model S batteries are made up of 18650s cylindrical Li-Ion cells. Tesla in every way tests them at different temperatures, current strength and even in crash tests. The collected data will be sent to manufacturers of cells for the correction of production - among them are Panasonic and Samsung.
Model S will go into mass production in 2012, and buyers will be able to choose a car with three battery capacity options: at 257, 370 and 483 km from one recharge. Model S will accelerate to 100 km / h in 5.6 seconds, and the maximum speed is declared at 193 km / h.
Tesla batteries rank first in charge density among all electric vehicles, and the company is working to further improve this indicator. Although competitors are trying different technologies, Tesla still prefers the same batteries that are used in laptops
The liquid cooling system should increase the battery life to 7 years or 160 thousand km. This is much more than in the current “Roadster” (3 years / 58 thousand km). By the way, in Model S the liquid cooling system will also cool the electric motor.
Roadster production stops in 2011, when the contract with Lotus ends, but you can even buy manufactured Roadsters even in 2012. Build the Model S will begin in mid-2012, and sales soon after.