Analyze the difference between lithium batteries with BMS and without BMS

If a lithium battery has a BMS, it can control the lithium battery cell to work in a specified working environment without explosion or combustion. Without a BMS, the lithium battery will be prone to explosion, combustion and other phenomena. For batteries with BMS added, the charging protection voltage can be protected at 4.125V, the discharge protection can be protected at 2.4V, and the charging current can be within the maximum range of the lithium battery; batteries without BMS will be overcharged, overdischarged, and overcharged. flow, the battery is easily damaged.

The size of the 18650 lithium battery without BMS is shorter than that of the battery with BMS. Some devices cannot use the battery with BMS due to the initial design. Without BMS, the cost is low and the price will be relatively cheaper. Lithium batteries without BMS are suitable for those with relevant experience. Generally, do not over-discharge or overcharge. The service life is similar to that of BMS.

The differences between an 18650 lithium battery with battery BMS and without BMS are as follows:

1. The height of the battery core without a board is 65mm, and the height of the battery core with a board is 69-71mm.

2. Discharge to 20V. If the battery does not discharge when it reaches 2.4V, it means there is BMS.

 3. Touch the positive and negative stages. If there is no response from the battery after 10 seconds, it means it has BMS. If the battery is hot, it means there is no BMS.

Because the working environment of lithium batteries has special requirements. It cannot be overcharged, over-discharged, overtemperature, or overcurrent charged or discharged. If there is, it will explode, burn, etc., the battery will be damaged, and it will also cause a fire. and other serious social problems. The main function of the lithium battery BMS is to protect the cells of rechargeable batteries, maintain safety and stability during battery charging and discharging, and play an important role in the performance of the entire lithium battery circuit system.

The addition of BMS to lithium batteries is determined by the characteristics of lithium batteries. Lithium batteries have safe discharge, charging, and overcurrent limits. The purpose of adding BMS is to ensure that these values do not exceed the safe range when using lithium batteries. Lithium batteries have limited requirements during the charging and discharging processes. Take the famous lithium iron phosphate battery as an example: charging generally cannot exceed 3.9V, and discharging cannot be lower than 2V. Otherwise, the battery will be damaged due to overcharging or over-discharging, and this damage is sometimes irreversible.

Usually, adding BMS to a lithium battery will control the battery voltage within this voltage to protect the lithium battery. The lithium battery BMS realizes equal charging of every single battery in the battery pack, effectively improving the charging effect in series charging mode.