How to test the current in the charging point of the lithium battery?

Current testing and charging and discharging control circuits are an important part of the lithium battery protection circuit. When the current test circuit detects that the charging and discharging currents are too large, the lithium battery protection circuit cuts off the charging circuit by closing the overcharge or overdischarge control tube, so as to achieve the purpose of protecting the lithium battery. At present, lithium battery protection circuits with current test circuits are mainly dedicated integrated circuits. These ASICs have the problems of high cost and low test current. The charging current test circuit includes a current test chip CC6902, a controller, a decoupling capacitor C1, a noise reduction capacitor C2, an over-discharge control tube, and an over-charge control tube; the negative electrode of the lithium battery is connected to the source and ground of the over-discharge control tube. The drain of the discharge control tube is connected to the drain of the overcharge control tube, and the source of the overcharge control tube is connected to the negative pole P- of the battery system. CC6902 integrates a high-precision, low-noise linear Hall circuit and a low-impedance main current wire. When the sampling current flows through the main current wire, the magnetic field that appears on the Hall circuit induces a corresponding electrical signal, and the signal resolution circuit outputs a voltage signal, making the product easier to use. When charging and discharging the lithium battery, the current test circuit outputs a voltage signal according to the magnitude of the current. The controller performs AD conversion on the voltage signal, and the converted value is judged as overcharge or overdischarge, and overcharge or overdischarge occurs. When discharging, the charging and discharging current is controlled by the overcharge control tube or the overdischarge control tube, which can test the charging and discharging current of up to tens of amperes at a very low cost, which handles the charging current test in the existing lithium battery protection circuit The circuit cost is high and the test circuit is small. The CC6902 selected in this circuit is a high-performance single-ended output linear current sensor. The product series has several specifications of 5A/10A/20A/30A, and the corresponding specifications can be selected according to the size of the test current. When the lithium battery is charged and discharged, the current test circuit outputs a voltage signal according to the magnitude of the current, and the controller performs AD conversion on the voltage signal, and the converted value performs the judgment of overcharge or overdischarge. When overcharge or overdischarge occurs , Through the overcharge control tube or overdischarge control tube to control the charging and discharging current, which can test the charging and discharging current of up to tens of amperes at a very low cost, and deal with the cost of the charging current test circuit in the existing lithium battery protection circuit High, small problems in the test circuit. CC6902 can be more effective for alternating current (AC) or direct current (DC) current testing methods, widely used in industrial, consumer and communications equipment. Importantly include motor control, load monitoring system, switching power supply and over-current fault protection. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete.