Today, I will continue to learn about the BMS hardware solutions of excellent domestic manufacturers. This analysis focuses on a BMS control board designed by Great Wall Euler Automobile for Honeycomb Energy.

bms

The compatible car model is likely the Euler Haomao, and the battery pack with this control board is shown below:

The BMS acquisition board and control board are arranged on top of the battery, and the cell sampling is connected through a wire harness, similar to a centralized type.

The front of the BMS control board is shown below. Its size is about 220mm120mm20mm, which is relatively thin. The housing is divided into two upper and lower parts, made of plastic (PA6-GF15), and is black. The protection level is about IP3X, and the entire product is fixed through the installation feature holes on the left and right sides of the housing, with a total of four, and the asymmetric structure is used to prevent mistakes.

The upper and lower housings are connected by snaps. To remove the lower housing, expose the inner PCBA, as shown below:

The PCBA is fixed to the upper housing with four screws.

BMS
BMS

Remove the screws and take out the PCBA board, as shown below:

The screws are fixed at the four corners, corresponding to the four metallized vias reserved at the four corners of the PCBA.

BMS

Next, let's take a look at this PCBA. The T side is shown below:

Its approximate size is 182mm115mm12mm, the PCB is green overall, 6 layers, 1.6mm thick; three-proof paint covers all components, and the three-proof paint material is quite hard.

BMS

Look at the local details, the PCB surface treatment is ENIG, the vias are filled with green oil, the location numbers of components and test points are all displayed with silk screen, and the smallest component package on the board is 0402.

BMS

Here I would like to add a piece of knowledge, that is, the difference between gold plating and immersion gold in PCB surface treatment, as explained below. In addition, some people say that ENIG is a kind of immersion gold process, and some people say that it is a combination of gold plating and immersion gold. I tend to agree with the latter. Generally, ENIG process is used more in automotive electronic components.

BMS

The B side of the PCBA is shown below:

In addition to resistors and capacitors, there are also some chips and diodes arranged on this side. Overall, there is still some space, and the three-proof paint also covers all components.

BMS

There are a total of 6 connectors on the entire board, distributed on two adjacent sides of the board. Among them, the two on the left are pin-type, which seem to be used for high-voltage sampling input. The PITCH is relatively large. From the board, it can also be seen that this controller integrates high-voltage sampling. There is a clear isolation strip on the PCB; the bottom side is four patch-type connectors, the three on the right are used for low-voltage signal transmission, and the one on the left looks like a daisy chain communication. In addition, no current shunt for current sampling is currently seen on the board, and it is not yet clear whether it is arranged outside or using a Hall sensor.

BMS

This time, only the structure, process and other information are introduced, and the circuit modules will be analyzed later.

Conclusion

In recent years, I have analyzed many excellent BMS products in a vertical direction. I plan to compare them horizontally in the future. With a certain function as the goal, I will compare the differences between each company to see if there are any innovative ideas that can be summarized. The above is for reference only.

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