Tesla dismantled battery pack

We all know that the 85kWh version of the Tesla battery pack consists of nearly 7,000 18650 Lithium Batteries. But the actual situation of the battery pack, but not many people have seen it. Most of the previous battery analysis published on the Internet was based on Tesla's battery patent. This time, GeekCar's little friends unveiled the last layer of Tesla battery.

Battery module

This picture is a panoramic view of the entire battery pack of the Model S chassis. The Model S has a total of 16 battery packs. The bottom of the block has two batteries. The above picture has been removed by the Ranger.

Tesla covers a single fiberglass panel on each battery pack to provide simple protection for the battery. There are metal beams separated between each two batteries. In the lower left corner of the figure is the fuse of the entire battery pack, and on the right is the coolant port of the battery and the coolant filler port.

Single battery pack

This is Tesla's very tall Lithium Battery pack. There are 444 batteries on this board. Each 74 sections are connected in parallel. The whole battery board is made up of 6 batteries in series. So we can figure out that there are a total of 7104 18650 lithium batteries on this Tesla Model S 85.

The 6 partitions of the battery pack are arranged in the red line of the above figure. The structure of the front and back of this panel is centrally symmetrical. As for why it is arranged in such a way, it must have been extensively tested and verified. GeekCar speculates that this arrangement is to achieve lower average resistivity and better heat dissipation with the heat sink.

The wires in the middle of the battery pack are connected to the battery plates on one side and to the battery control module on the other. These lines are used to detect the voltage of the battery pack to ensure the normal operation of the battery pack.

Looking closely, you can find that each battery has a very thin fuse. This is used to protect the entire battery pack. When a single battery has an abnormal temperature such as excessive temperature, the fuse will automatically blow. The purpose of protecting the entire battery pack is achieved (one fuse at the positive and negative terminals of each battery).

The fact that so many fuses need to be soldered to the board is a very large project, and it should be done by a special robot using ultrasonic welding.

BMS master chip

Tesla's battery main control module, from the printed logo on the PCB, this board is completely developed by Tesla. A large number of resistors and capacitors are used on the board for signal conditioning. There are six sets of electrical signal acquisition lines on the side we see.

Because Tesla uses a 18650 lithium battery, this lithium battery is the battery used in our laptops, so its electronic control technology is very mature, although I think a lot of methods still can not see the model of the chip on the motherboard, However, it can be inferred that there are mainly charge and discharge management chips and battery metering management chips. Compared with laptop batteries, the complicated place should be in multi-channel battery signal acquisition and control algorithms. After all, electric vehicles have hundreds of batteries. Monitoring and laptop battery monitoring at around 10 knots is not an order of magnitude.