CN-224218123-U - Charging control circuit

CN224218123UCN 224218123 UCN224218123 UCN 224218123UCN-224218123-U

Abstract

The utility model provides a charging control circuit which can be applied between a lithium battery pack and a charger and is used for charging control, the charging control circuit comprises a pre-charging unit and a driving unit, the pre-charging unit comprises a pre-charging switch PM2, a current limiting resistor R7 and a differential pressure loop connected in parallel with two ends of the pre-charging switch PM2 and the current limiting resistor R7, the pre-charging switch PM2 and the current limiting resistor R7 are connected in series between the lithium battery pack and the charger, the control end of the pre-charging switch is connected in the differential pressure loop, the pre-charging unit is used for carrying out low-current charging on the lithium battery pack, and the driving unit is connected between the lithium battery pack and the charger and is used for feeding back starting voltage provided by the lithium battery pack to the charger. The utility model can solve the abnormal and unstable charging condition.

Inventors

WANG CHAO
ZHANG GANG

Assignees

深圳市比比赞科技有限公司

Dates

Publication Date: 20260508
Application Date: 20250520

Claims (8)

1. A charge control circuit applicable between a lithium battery pack and a charger and used for charge control, characterized in that the charge control circuit comprises a precharge unit and a driving unit; The pre-charging unit comprises a pre-charging switch PM2, a current limiting resistor R7 and a voltage difference loop connected in parallel with two ends of the pre-charging switch PM2 and the current limiting resistor R7, wherein the pre-charging switch PM2 and the current limiting resistor R7 are connected in series between the lithium battery pack and the charger, a control end of the pre-charging switch is connected in the voltage difference loop, and the pre-charging unit is used for carrying out low-current charging on the lithium battery pack; And the driving unit is connected between the lithium battery pack and the charger and is used for feeding back the starting voltage provided by the lithium battery pack to the charger.
2. The charge control circuit according to claim 1, wherein the voltage difference loop comprises a zener diode ZD2, a resistor R5 and a resistor R6, wherein a negative electrode of the zener diode ZD2 is connected between the precharge switch PM2 and the lithium battery pack, a positive electrode of the zener diode ZD2 is connected with the resistor R5, the other end of the resistor R5 is connected with the resistor R6, the other end of the resistor R6 is connected with a charger, a control end of the precharge switch PM2 is connected between the zener diode ZD2 and the resistor R5, and the precharge switch PM2 is a P-communication field effect transistor.
3. The charge control circuit of claim 2, wherein the resistor R6 is connected to a negative terminal P-one of the charger and a diode D1 is further connected to the negative terminal P-one of the charger, and a positive electrode of the diode D1 is connected to the resistor R6.
4. A charge control circuit according to claim 3, wherein the drive unit comprises a first drive loop comprising a precharge switch PM1, the precharge switch PM1 being connected between the lithium battery pack and a feedback terminal of a charger, a control terminal of the precharge switch PM1 being connected between the lithium battery pack and the precharge switch PM 2.
5. The charge control circuit of claim 4, wherein the drive unit further comprises a second drive loop comprising a precharge switch Q1, the precharge switch Q1 being connected between the precharge switch PM2, precharge switch PM1, and a lithium battery pack.
6. The charge control circuit of claim 5, wherein the first driving circuit further comprises a resistor R3 and a resistor R4, the precharge switch PM1 is a P-channel fet, a source of the precharge switch PM1 is connected between the positive terminal b+ of the lithium battery pack and the positive terminal p+ of the charger, a drain of the precharge switch PM1 is connected to the feedback terminal of the charger, a gate of the precharge switch PM1 is connected between the resistor R3 and the resistor R4, the other end of the resistor R3 is connected between the positive terminal b+ of the lithium battery pack and the positive terminal p+ of the charger, and the other end of the resistor R4 is connected to the precharge switch Q1.
7. The charge control circuit of claim 6 wherein the second drive loop further comprises a resistor R1 and a resistor R2, the precharge switch Q1 is a PNP transistor, the collector of the precharge switch Q1 is connected to the resistor R4, the emitter of the precharge switch Q1 is connected between the negative terminal B-of the lithium battery pack and the source of the precharge switch PM2, the base of the precharge switch Q1 is connected between the resistor R1 and the resistor R2, the other end of the resistor R1 is connected between the positive terminal b+ of the lithium battery pack and the positive terminal p+ of the charger, and the other end of the resistor R2 is connected between the negative terminal B-of the lithium battery pack and the source of the precharge switch PM 2.
8. The charge control circuit of claim 7 wherein a capacitor C is connected in parallel across the resistor R2.

Description

Charging control circuit Technical Field The utility model relates to the technical field of batteries, in particular to a charging control circuit. Background In energy storage products, lithium ion batteries may experience overdischarge during long-term storage, excessive use, etc., and voltage drops below a charger identification threshold. The charging circuits of many chargers in the current market are all software control schemes by using a singlechip for control or a relay for switch control, and the like, and generally comprise a main control IC, a plurality of MOS (metal oxide semiconductor) tubes and a plurality of resistors, wherein the main control IC is easy to be incapable of working normally due to undervoltage, and the charging and discharging MOS tubes are all closed. After the charger is connected, the MOS tube is started by adjusting the resistance value of the specific resistor, a special charging loop is formed for charging the battery, when the voltage of the lithium battery pack is charged to the main control IC to enable the main control IC to work normally, the MOS tube is closed, and the system resumes normal charging. If the resistor parameter is improperly selected or the performance of the MOS tube is unstable, the charging is abnormal, and even the MOS tube and the lithium battery pack are damaged. Disclosure of utility model The utility model mainly aims to provide a charging control circuit which is used for solving the problems in the prior art. To achieve the above and other related objects, the present utility model provides a charge control circuit applicable between a lithium battery pack and a charger and used for charge control, the charge control circuit including a precharge unit and a driving unit. The pre-charging unit comprises a pre-charging switch PM2, a current limiting resistor R7 and a voltage difference loop connected in parallel with two ends of the pre-charging switch PM2 and the current limiting resistor R7, wherein the pre-charging switch PM2 and the current limiting resistor R7 are connected in series between the lithium battery pack and the charger, a control end of the pre-charging switch is connected in the voltage difference loop, and the pre-charging unit is used for carrying out low-current charging on the lithium battery pack. And the driving unit is connected between the lithium battery pack and the charger and is used for feeding back the starting voltage provided by the lithium battery pack to the charger. As a preferred scheme, the voltage-differential loop comprises a zener diode ZD2, a resistor R5 and a resistor R6, wherein the negative electrode of the zener diode ZD2 is connected between the precharge switch PM2 and the lithium battery pack, the positive electrode of the zener diode ZD2 is connected with the resistor R5, the other end of the resistor R5 is connected with the resistor R6, the other end of the resistor R6 is connected with a charger, the control end of the precharge switch PM2 is connected between the zener diode ZD2 and the resistor R5, and the precharge switch PM2 is a P-communication field effect transistor. As a preferable scheme, the resistor R6 is connected with the negative electrode P-end of the charger, and is further connected with a diode D1, and the positive electrode of the diode D1 is connected with the resistor R6. As a preferred solution, the driving unit includes a first driving circuit, the first driving circuit includes a precharge switch PM1, the precharge switch PM1 is connected between the lithium battery pack and a feedback terminal of the charger, and a control terminal of the precharge switch PM1 is connected between the lithium battery pack and the precharge switch PM 2. As a preferred solution, the driving unit further includes a second driving circuit including a precharge switch Q1, and the precharge switch Q1 is connected between the precharge switch PM2, the precharge switch PM1, and the lithium battery pack. As a preferred scheme, the first driving circuit further includes a resistor R3 and a resistor R4, the precharge switch PM1 is a P-communication field effect transistor, a source electrode of the precharge switch PM1 is connected between the positive terminal b+ of the lithium battery pack and the positive terminal p+ of the charger, a drain electrode of the precharge switch PM1 is connected with the feedback terminal of the charger, a gate electrode of the precharge switch PM1 is connected between the resistor R3 and the resistor R4, the other end of the resistor R3 is connected between the positive terminal b+ of the lithium battery pack and the positive terminal p+ of the charger, and the other end of the resistor R4 is connected with the precharge switch Q1. As a preferred scheme, the second driving circuit further includes a resistor R1 and a resistor R2, the precharge switch Q1 is a PNP transistor, a collector of the precharge switch Q1 is connected to the resistor R4, an emitter of