Series battery charge up circuit with charge compensate function

Abstract

The present invention provides a charging control circuit which can compensate the charging for battery with lower voltage in series battery set during charging and enables the terminal voltage of independent battery in series battery set to tend to uniform. The charging control circuit can detect the terminal voltage of the independent battery in series battery set in real time during charging and compensate charging for the battery with lower terminal voltages through a compensation charging circuit, thereby making up the differences of the initial state and the charging/discharging characteristics for independent battery in the battery set, unleashing the loading capability of the independent battery while making sure the independent battery has no over-charging and improving charging and discharging efficacy of the power battery.

Description

Technical field [0001] The invention relates to a circuit for controlling the charging of series battery packs, in particular to controlling the charging of large-capacity power batteries, which belongs to the electrical control category. Background technique [0002] The power battery is the power source for electric loads such as electric tools, electric vehicles, electric bicycles, and emergency lighting. The power battery is a battery pack composed of multiple single cells in series. The higher the voltage, the more the number of single cells that need to be connected in series. Due to the control accuracy of the production process, there are differences in the various electrochemical parameters of each single battery, making it difficult to achieve complete consistency in the capacity, charge and discharge characteristics, and initial state of the single battery. Using a well-known method to connect multiple single cells in series to form a battery pack. After the powe...

AI Technical Summary

Problems solved by technology

Due to the control accuracy of the production process, there are differences in the various electrochemical parameters of each single battery, making it difficult to achieve complete consistency in the capacity, charge and discharge characteristics, and initial state of the single battery

Using a well-known method to connect multiple single cells in series to form a battery pack. After the power battery is made, the characteristics and initial state differences of each battery are retained in the battery pack. During the charging and discharging process, each unit in the battery pack The current passed by the bulk battery is the same. Due to the differences in the characteristics and initial states of each battery, the charging capacity of each battery cannot be fully utilized, which reduces the charging and discharging efficiency of the battery pack or power battery. The more serious situation is , with the continuous increase of charging-discharging times in use, the differences in the state, charging / discharging characteristics and charging capacity of each battery that make up the battery pack will gradually increase, resulting in some batteries being "overcharged" during charging, and some batteries being "overcharged" during discharging. Battery "over-discharged"

Both "overcharging" and "overdischarging" will cause irreversible damage to the battery. The damaged battery will generate a lot of heat during the subsequent charging and discharging process, which will seriously affect the overall discharge efficiency and service life of the power battery, and will also bring serious damage to the charging and discharging process. Security risks

[0003] Chinese patent ZL00137155.X discloses a circuit scheme for controlling the charging and discharging of a battery pack in series, which connects the batteries that make up the battery pack in series, and detects the voltage, temperature and current of the battery pack in real time during the charging and discharging process , take the method of reducing charging power or discharging power to protect each battery in the battery pack, which can effectively prevent the battery from "overcharging", "over-discharging" and "overheating", but it cannot compensate for the individual batteries that make up the battery pack in series. Due to the difference in initial state and the difference in charging / discharging characteristics, the charging capacity of each battery cannot be fully utilized, which reduces the charging and discharging efficiency of the battery pack or power battery

For a large-capacity power battery pack, the charging current is large. In order to make the equalization circuit work effectively, its power dissipation must be increased, resulting in a large amount of heat, resulting in energy waste and low charging efficiency.

In order to meet the heat dissipation requirements, the control equipment is huge

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