How to optimize the lithium-ion battery charging system?

How to optimize the lithium-ion battery charging system? Battery charger output short-circuit and overcharge current protection In some computing applications, the most common lithium-ion battery is the 18650 lithium-ion battery with a capacity between 2200 and 2600 mAh. When the charging rate is 0.7°C, the charging current of a 12-v or 19-v adapter is about 2-4a. Efficient charging requires synchronous switching of the buck topology. When the device has component failure or abnormal operation (such as charger output short circuit, sensor short circuit, etc.), a smokeless charging system is also required. The charger must have such a protection mechanism to prevent fire or smoke. Battery charging safety It is dangerous to charge lithium-ion batteries at very low or very high battery temperatures. LiCoO2 anode lithium ion battery may explode when 4.3v reaches 175℃. Many published safety regulations for industrial battery chargers (such as the Japan Electronics and Information Technology Industries Association (JEITA), etc.) aim to achieve safe charging by reducing the charging current and voltage of the battery at low or high battery temperatures. Adapter input and battery overvoltage protection (OVP) In the case of notebook computers, 19-v and 16-v adapters are generally used, while smart phones usually use 5-v adapters. Netbooks, umpc and mids usually use these adapters to save development costs, but they usually do not require 19V adapters to charge one to three batteries in series. In addition, IEEEP1725 requires the system to include an input adapter and a battery OVP. If these portable devices encounter input voltage, it will prevent you from starting the system. If the battery is overcharged, please turn off the charger immediately. If a reverse adapter voltage occurs, the system cannot start. Protect the IC function from over-discharge: In the case of over-discharge, the electrolyte will decompose and deteriorate the battery characteristics, resulting in a decrease in the number of recharges. Lithium-ion battery protection IC is used to protect its over-discharge state, so as to achieve protection purposes. Excessive charge: When the lithium-ion battery is overcharged, the electrolyte in the battery will decompose, causing the temperature to rise and the appearance of gas, which may cause the risk of spontaneous combustion or knocking. The lithium-ion battery protection IC is to prevent Occurrence of overcharge. Over-current and short-circuit current If over-current or short-circuit current occurs due to unknown reasons (during discharge or when the anode and cathode are accidentally touched by metal), the discharge should be stopped to ensure safety. The new feature of lithium-ion battery protection IC lock: the protection integrated circuit will turn off the power MOS (Cout) after a period of delay time when charging, in order to achieve the purpose of protection. When the lithium-ion battery voltage decreases, the deletion point (overload hysteresis voltage) ) Will reply, and will continue to charge, this time and protection, and discharge of electric charge, this situation is not a good position and safety issues will not be effectively resolved. Shorten test time: Assuming that it takes 1 second to test one PCB and 1 million seconds to 1 million PCBs, this is very time-consuming and inefficient. We can use the following functions to shorten the test time. Over-current protection during charging: When the charger is connected to the charger, over-current suddenly occurs (the charger is damaged), that is, over-current is detected during charging. At this time, Cout will be protected by high and low power MOS switches. Shrink protection circuit components: encapsulate the delay capacitor for overcharge and short circuit protection into the protection IC. Statement: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete the previous article: Analysis of iron phosphate Advantages of lithium-ion batteries