Novel lithium-ion power battery protective circuit

Abstract

The invention relates to a novel lithium-ion power battery protective circuit. The protective circuit comprises a protective chip, an anode loop, a cathode loop and a control circuit, wherein the anode loop and the cathode loop are respectively connected with the anode and the cathode of a battery; the protective circuit detects the voltage of the core of the battery; a control circuit is in series connection with the anode loop; the protective circuit controls the on-off state of the control circuit; the anode loop comprises a charging anode loop and a discharging anode loop; the charging anode loop is in series connection with an electronic control switch; the control end of the electronic control switch is connected with the control signal output end of the protective circuit; the discharging anode loop is connected with two electronic control switches which are in parallel connection with each other; and the control ends of the electronic control switches in parallel connection are connected to the control signal output ends of the protecting circuit. During discharging, by using the novel lithium-ion power battery protective circuit, the internal resistance of a group of field effect transistors is reduced, so that the temperature is lower during discharging, the discharging efficiency is high and the cost can be reduced.

Description

technical field [0001] The invention relates to a novel lithium power battery protection circuit. Background technique [0002] At present, the maximum working current of the lithium power battery in the industry is 20 amps or above. In the lithium power battery protection circuit, because the charge and discharge control field effect transistors are placed on the same circuit of the circuit, the biggest disadvantage of the circuit is: it works when discharging. High temperature at high current; large internal resistance of the battery; low discharge efficiency; high cost and other problems. Please see attached figure 2 , figure 2 It is a typical circuit architecture used by lithium power batteries in the industry at present. Its control principle is: FET Q1 and FET Q2 are charging control FETs. When the voltage of a cell in the lithium battery is higher than the overcharge voltage , the protection IC outputs a high potential to turn off the charging control FET Q1 and FE...

AI Technical Summary

Problems solved by technology

Due to the large current discharge, the positive current of the lithium battery passes through the field effect transistor Q3, the field effect transistor Q4, the field effect transistor Q1, the field effect transistor Q2 field effect transistor to the P+ output, and the internal resistance of the battery during discharge = the internal resistance of the line + (Q1 internal resistance + Q2 internal resistance) / 2+(Q3 internal resistance +Q4 internal resistance) / 2; and when high current discharges, FET Q1, FET Q2; FET Q3, FET Q4 will all Generate heat source, also affect battery discharge efficiency

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