Until recently, Tesla has used 18650 lithium-ion battery cells exclusively to power its two electric car models, the Model S sedan and Model X SUV. The nomenclature means each cell is 18 millimeters in diameter and 65 millimeters in length — just slightly larger than a standard AA battery.
Basically, a lithium-ion battery has three components — an anode where lithium ions collect during charging, a cathode that sends electrons to an electric motor, and a chemical soup in between that allows the ions to transfer back and forth between the two.
Model S & Model X Battery Configuration
In the company’s 85 and 90 kWh batteries, there are 16 battery packs containing 444 cells each. For its 100 kWh batteries, Tesla reconfigured the cooling system so it could fit 516 cells into each of the 16 packs for a total of 8,256 cells.
Although Tesla does not warranty its batteries against power degradation, real-world driving experience indicates that the batteries lose no more than 2% of their capacity per year. That means the fears of Tesla owners when the cars first went on sale in 2012 that they might have to buy a new battery every 5 years or so were unfounded.
You can learn more about how a battery and a motor work together to power a Tesla automobile in the video below.
Model 3 Battery Is Different
Tesla is using a different battery cell for the the Model 3. Known as a 2170 cell, it is 21 millimeters in diameter by 70 millimeters in length. That makes is slightly larger than the 18650 cells used in the Model S and Model X, but size can be deceptive. The new cells are 46% larger in volume and about 15% more energy efficient than the 18650 cells, according to J.B. Straubel, Tesla’s chief technology officer.
The Model 3 will be available with either a 50 kWh or 75 kWh battery. The car with the smaller battery will have 220 miles of range while the car with the larger battery will travel 310 miles on a single battery charge. Not much is known at this time about how many battery packs the new car has or how many cells are in each pack.
Elon Musk has said previously that 75 kWh was the largest battery that will fit into the Model 3 chassis. Nevertheless, the EPA says that battery has a maximum of 80.5 kWh of energy and a 258 horsepower motor. The 75 kWh rating by the company may be the battery’s usable energy rather than its calculated theoretical maximum.
Tesla is only building a single-motor car at the present time. The dual-motor cars will not go into production until late this year or early in 2018, according to tweets from Elon Musk and MyTesla estimates.
Is Tesla Battery Indestructible?
Some potential electric car buyers are concerned that the battery in their car may become a danger in a collision. The father and son team behind YouTube channel “What’s Inside?” bought a battery pack from a wrecked Tesla and put it through a torture test. They threw it off the roof — twice. They ripped it apart, then hacked some of the cells to pieces with an ax.
Both survived their deliberate misadventures. If the Tesla battery can survive this rough treatment, it can survive almost anything.