A friend asked me about the choice of BMS. Today I will share with you how to buy a suitable BMS simply and effectively.
I. Classification of BMS
1. Lithium iron phosphate is 3.2V
2. Ternary lithium is 3.7V
The simple way is to directly ask the manufacturer who sells the BMS and ask him to recommend it to you.
II. How to choose protection current
1. Calculate according to your own load
First, calculate your charging current and discharge current. This is the basis for choosing a protective board.
For example, for a 60V electric vehicle, the charging is 60V5A, and the discharge motor is 1000W/60V=16A. Then choose a BMS, charging should be higher than 5A, and discharging should be higher than 16A. Of course, the higher the better, after all, it is best to leave a margin to protect the upper limit.
2. Pay attention to the charging current
Many friends buy BMS, which has a large protective current. But I didn't pay attention to the charging current problem. Because the charging rate of most batteries is 1C, your charging current must not be greater than the rate of your own battery pack. Otherwise, the battery will explode and the protective plate will not protect it. For example, the battery pack is 5AH, I charge it with a current of 6A, and your charging protection is 10A, and then the protection board does not work, but your charging current is higher than the battery charging rate. This will still damage the battery.
3. The battery must also be adapted to the protective board.
If the battery discharge is 1C, if you choose a large protective board, and the load current is higher than 1C, the battery will be easily damaged. Therefore, for power batteries and capacity batteries, it is best to calculate them carefully.
III. Type of BMS
The same protective plate is suitable for machine welding and some for manual welding. Therefore, it is convenient to choose someone yourself so that you can find someone to process the PACK.
IV. The simplest way to choose
The stupidest way is to ask the protective board manufacturer directly! No need to think about a lot, just tell the charging and discharging loads, and then it will adapt it for you!
Post time: Nov-29-2023
