Lithium battery equalization circuit
The MCU-controlled equalization circuit detects the voltage of individual cells and performs active equalization when the voltage difference reaches 0.1V, which solves the problem of unbalanced individual cells in lithium battery packs and improves safety and lifespan.
Patent Information
- Application Number
- CN202520458339.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2035-03-17
AI Technical Summary
Imbalance between individual cells in a lithium battery pack can lead to overcharging during charging and over-discharging during discharging, increasing the risk of accidents and affecting the lifespan of the battery pack.
An MCU-controlled equalization circuit detects the voltage of individual cells and controls the MOSFET to perform equalization when the voltage difference reaches 0.1V, thus achieving active equalization.
Improve the safety of lithium batteries, avoid overcharging and over-discharging, and extend the life of battery packs.
Smart Images
Figure CN223912269U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to lithium battery pack equalization technology, especially a kind of lithium battery equalization circuit. BACKGROUND
[0002] Due to the battery pack of lithium battery multiple battery series-parallel connection is after long time charging and discharging use, unbalanced phenomenon will appear between its internal each single battery.
[0003] When charging, some batteries have been charged, and some batteries have not been charged well. Or one or two batteries have been fully charged, and most of them have not been charged well. In this way, the difference between battery capacity and voltage becomes more and more obvious, and the battery that has been charged first will be overcharged, and even overheat, explosion and fire accidents will occur.
[0004] When discharging, some batteries have been discharged, and some batteries have not been discharged. In this way, over-discharge will occur, which will shorten the service life of the battery pack, and even explosion and fire accidents will occur. The reason for these phenomena is the imbalance of the battery. Therefore, the battery pack needs to be balanced. INVENTION CONTENTS
[0005] The utility model aims at: provide a kind of scheme for the equalization treatment of lithium battery, make lithium battery more safe.
[0006] The technical scheme of the utility model is:
[0007] The lithium battery equalization circuit includes N single battery cells in series, an equalization circuit including MCU, voltage detection circuit and N-way drive circuit; the voltage detection circuit detects the voltage of each single battery cell and sends it to the MCU, and the N outputs of the MCU are respectively connected to the control end of each drive circuit, and the output end of each drive circuit is respectively connected to the positive electrode of each single battery cell, to realize the opening and closing of the active equalization of the corresponding single battery cell.
[0008] Preferably, the drive circuit includes MOS tube Q1, transistor Q2 and resistors R1, R2, R3, R4 and R5, the source of the MOS tube Q1 is connected to the positive electrode of the corresponding single battery cell, the drain is connected to the negative electrode of the corresponding single battery cell through the resistor R4, the gate is connected to the positive electrode of the corresponding single battery cell through the resistor R1, and the gate is also connected to the collector of the transistor Q2 through the resistor R2; the emitter of the transistor Q2 is grounded, the base is grounded through the resistor R5, and the base is also connected to the output end of the corresponding MCU through the resistor R3.
[0009] Preferably, the resistor R4 and the negative electrode of the corresponding single battery cell are also connected in series with a diode D1, the anode of the diode D1 is connected to the resistor R4, and the cathode is connected to the negative electrode of the corresponding single battery cell.
[0010] Preferably, the MCU controls the MOS on the equalization circuit to perform equalization processing, and when it is detected that the voltage of the maximum and minimum two sections of the lithium battery is greater than 0.1V, the MOS is controlled to open to perform equalization.
[0011] Preferably, the MOS tube Q1 is a PMOS tube, and the transistor Q2 is an NPN transistor.
[0012] The utility model discloses the advantages are:
[0013] The lithium battery equalization circuit provided by the utility model is composed of MCU and equalization control circuit. BRIEF DESCRIPTION OF DRAWINGS
[0014] The utility model will be further described in connection with the drawings and embodiments:
[0015] Figure 1 It is the schematic diagram of the active equalization control circuit of the lithium battery group in the embodiment. DETAILED DESCRIPTION
[0016] As Figure 1 The lithium battery equalization circuit of the embodiment, the lithium battery includes three single cells connected in series, and the equalization circuit includes MCU, a voltage detection circuit and three driving circuits.
[0017] The third driving circuit includes a MOS tube Q1, a transistor Q2 and resistors R1, R2, R3, R4 and R5.
[0018] The MCU controls the MOS on the equalization circuit to perform equalization processing, and when it is detected that the voltage of the maximum and minimum two sections of the lithium battery is greater than 0.1V, the MOS is controlled to open to perform equalization.
[0019] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any modification made according to the spirit and essence of the main technical scheme of the present application should be covered within the protection scope of the present application.
Claims
1. A lithium battery equalization circuit, characterized by, The lithium battery comprises N single cells connected in series, and the equalization circuit comprises an MCU, a voltage detection circuit and N driving circuits; the voltage detection circuit detects the voltage of each single cell and sends the voltage to the MCU, N output ends of the MCU are connected to control ends of each driving circuit respectively, and output ends of each driving circuit are connected to anodes of each single cell respectively, so that the opening and closing of active equalization of the corresponding single cell are realized.
2. The lithium battery equalization circuit of claim 1, wherein, The driving circuit comprises a MOS tube Q1, a transistor Q2 and resistors R1, R2, R3, R4 and R5; the source of the MOS tube Q1 is connected to the anode of the corresponding single cell, the drain is connected to the cathode of the corresponding single cell through the resistor R4, the gate is connected to the anode of the corresponding single cell through the resistor R1, and the gate is also connected to the collector of the transistor Q2 through the resistor R2; the emitter of the transistor Q2 is grounded, the base is grounded through the resistor R5, and the base is also connected to the output end of the corresponding MCU through the resistor R3.
3. The lithium battery equalization circuit of claim 2, wherein, The resistor R4 and the cathode of the corresponding single cell are also connected in series with a diode D1, the anode of the diode D1 is connected to the resistor R4, and the cathode is connected to the cathode of the corresponding single cell.
4. The lithium battery equalization circuit of claim 3, wherein, The MCU controls the MOS on the equalization circuit to perform equalization processing, and when it is detected that the voltages of the maximum and minimum single cells in the lithium battery are greater than 0.1V, the MOS is controlled to be opened to perform equalization.
5. The lithium battery equalization circuit of claim 2, wherein, The MOS tube Q1 is a PMOS tube, and the transistor Q2 is an NPN transistor.