Charging implementation circuit for multiple lithium batteries

Abstract

The utility model discloses a charging realization circuit for multiple lithium batteries, which comprises a controller C. A current detection end I1, a grid driving end O1 and a voltage detection end I2 are arranged in the controller C. The current detection end I1 is connected in parallel with a resistor R1 and an inductor L1, the other end of the inductor L1 is connected in parallel with a diode D1 and an NMOS tube M1, the NMOS tube M1 is electrically connected with the grid driving end O1, and the voltage detection end I2 is connected in parallel with the diode D1. The output end of the diode D1 is connected with a capacitor C1, a resistor R2 and a battery pack Li-ion in parallel, the other end of the resistor R2 is connected with a voltage detection end I2 and a resistor R3 in parallel, the other end of the capacitor C1 is connected with the GND, and the other end of the resistor R3 is connected with the GND; according to the utility model, the asynchronous rectification Boost technology is adopted, the controller is used for charging control, the safe charging of the battery pack is realized under the condition of 5V input, and the adverse effect on the service life of the battery caused by overcharging can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a charging circuit for multiple lithium batteries. Background Art

[0002] Rechargeable batteries are a common power source, including lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries and lithium-ion batteries. Existing lithium-ion battery charging circuits generally use Figure 2 The linear constant current constant voltage charging circuit shown has an input voltage that must be higher than the battery voltage and lacks a charging procedure for determining the battery voltage, which results in unsafe charging and can easily have an adverse effect on the battery life due to overcharging. Utility Model Content

[0003] The purpose of the utility model is to provide a charging circuit for multiple lithium batteries to solve the problems raised in the above background technology.

[0004] In order to solve the above technical problems, the utility model provides the following technical solutions: a charging circuit for multiple lithium batteries, including a controller C, wherein the controller C is provided with a current detection terminal I1, a gate drive terminal O1 and a voltage detection terminal I2, the current detection terminal I1 is connected in parallel with a resistor R1 and an inductor L1, the other end of the inductor L1 is connected in parallel with a diode D1 and an NMOS tube M1, and the NMOS tube M1 is electrically connected to the gate drive terminal O1, and the output end of the diode D1 is connected in parallel with a capacitor C1, a resistor R2 and a battery pack Li-ion.

[0005] Preferably, the other end of the resistor R2 is connected in parallel to the voltage detection end I2 and the resistor R3.

[0006] Preferably, the gate of the NMOS tube M1 is connected to the gate driving terminal O1, the source is connected to GND, and the drain is connected to the input terminal of the diode D1.

[0007] Preferably, the other end of the resistor R1 is connected to VIN.

[0008] Preferably, the other end of the capacitor C1 is connected to GND.

[0009] Preferably, the other end of the resistor R3 is connected to GND.

[0010] Preferably, the negative electrode of the Li-ion battery pack is connected to GND.

[0011] The utility model provides a multi-cell lithium battery charging circuit, which has the advantages that: the utility model adopts asynchronous rectification Boost technology and uses a controller to control charging, so as to achieve safe charging of the battery pack under the condition of 5V input, and can avoid adverse effects on battery life caused by overcharging. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is the circuit principle diagram of the utility model;

[0014] Figure 2 This is the schematic diagram of the existing charging circuit. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] See also Figure 1 The utility model provides an embodiment: a charging circuit for multiple lithium batteries, including a controller C, wherein a current detection terminal I1, a gate driving terminal O1 and a voltage detection terminal I2 are arranged in the controller C, a resistor R1 and an inductor L1 are connected in parallel to the current detection terminal I1, a diode D1 and an NMOS tube M1 are connected in parallel to the other end of the inductor L1, and the NMOS tube M1 is electrically connected to the gate driving terminal O1, a capacitor C1, a resistor R2 and a battery pack Li-ion are connected in parallel to the output end of the diode D1, the other end of the resistor R2 is connected in parallel to the voltage detection terminal I2 and the resistor R3, the gate of the NMOS tube M1 is connected to the gate driving terminal O1, the source is connected to GND, the drain is connected to the input end of the diode D1, the other end of the resistor R1 is connected to VIN, the other end of the capacitor C1 is connected to GND, the other end of the resistor R3 is connected to GND, and the negative electrode of the battery pack Li-ion is connected to GND.

[0017] Working principle: When using the utility model to charge the battery, first turn on the NMOS tube M1 to charge the inductor L1, and the current detection terminal I1 detects the current of the inductor L1. When the current rises to the set maximum value I hight When the gate drive terminal O1 turns to a low level, the NMOS tube M1 is turned off, and the inductor current drops to the set minimum value I low When the gate drive terminal O1 generates a high level, the NMOS tube M1 is turned on again, and the average current flowing through the inductor L1 is (Ihight +I low ) / 2, by adjusting I hight ,I low To change the charging current of the battery pack Li-ion; during constant voltage charging, the voltage detection terminal I2 detects a voltage rise and reduces the current; the voltage detection terminal I2 detects a voltage drop and increases the current; start trickle charging, the controller C detects the battery pack Li-ion voltage, if the voltage is less than or equal to 2.5V / Cell, do not charge, the voltage is greater than 2.5V / Cell and less than or equal to 3V / Cell, 0.1C trickle charging, the voltage is greater than 3V / Cell and less than 4.1V / Cell, 1C constant current charging, the voltage is greater than or equal to 4.1V / Cell, 4.2V / Cell constant voltage charging, detect the charging current, the current is less than 0.1C, shut down the charging, detect the battery voltage, the voltage is less than 4.1V / Cell, start constant voltage charging again.

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0020] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A multi-cell lithium battery charging circuit, comprising a controller C, characterized in that: The controller C is provided with a current detection terminal I1, a gate drive terminal O1 and a voltage detection terminal I2. The current detection terminal I1 is connected in parallel with a resistor R1 and an inductor L1. The other end of the inductor L1 is connected in parallel with a diode D1 and an NMOS tube M1, and the NMOS tube M1 is electrically connected to the gate drive terminal O1. The output end of the diode D1 is connected in parallel with a capacitor C1, a resistor R2 and a battery pack Li-ion.

2. A multi-cell lithium battery charging circuit according to claim 1, characterized in that: The other end of the resistor R2 is connected in parallel to the voltage detection end I2 and the resistor R3.

3. A multi-cell lithium battery charging circuit according to claim 1, characterized in that: The gate of the NMOS tube M1 is connected to the gate driving terminal O1, the source is connected to GND, and the drain is connected to the input terminal of the diode D1.

4. The multi-cell lithium battery charging circuit according to claim 1, characterized in that: The other end of the resistor R1 is connected to VIN.

5. The multi-cell lithium battery charging circuit according to claim 1, characterized in that: The other end of the capacitor C1 is connected to GND.

6. A multi-cell lithium battery charging circuit according to claim 2, characterized in that: The other end of the resistor R3 is connected to GND.

7. The multi-cell lithium battery charging circuit according to claim 1, characterized in that: The negative electrode of the Li-ion battery pack is connected to GND.

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