Adaptive lithium battery charging management circuit of power supply

Abstract

The invention discloses an adaptive lithium battery charging management circuit of a power supply. The management circuit comprises a reference voltage circuit, a cell voltage sampling network, a charging stopping circuit, a power supply voltage sampling network, a power supply adaptive charging control circuit, a trickle charging circuit, a constant-voltage charging circuit, a constant-temperature charging circuit and four paths of controlled switches. According to the invention, the management circuit is capable of automatically being suitable for and matching the output ability of the powersupply; when the output ability of the power supply is strong, the charging circuit works in a constant-current charging mode; when the output ability of the power supply is weak, the charging circuit carries out charging with the current provided by the power supply; based on the characteristics of a lithium battery, three-section type charging management, including the trickle charging management, the constant-current charging and constant-voltage charging management and the overheat protection constant-temperature charging management, for charging of the lithium battery is provided, so energy provided by the power supply can be effectively used; and the management circuit is especially suitable for application of a power supply device has unstable power supply ability like a solar cellin the charging of the lithium battery.

Description

technical field [0001] The invention belongs to the field of electronic technology, and relates to a power management technology, in particular to a lithium battery charging management technology powered by solar energy. Background technique [0002] With the development of new energy technology, solar cells are becoming more and more popular as a power supply source. Solar power generation, solar street lamps, portable charging equipment, etc. all use solar cells as a power source. However, solar cells will be affected by seasons, weather, and day and night changes, making the output current of their power generation unstable. When there is sufficient sunlight, the output current of solar cells is large, and when there is insufficient sunlight, the output current of solar cells is small. At night, solar cells are almost There is no current output. Therefore, the solar battery cannot be used alone as a power supply to power the device. It needs to be used together with a re...

AI Technical Summary

Problems solved by technology

But there is a problem with this charging method. When the energy of the power supply is insufficient, that is, when the output current of the power supply is much lower than the designed charging current, it is equivalent to adding a heavy load to the power supply, and the power supply will be pulled down, causing the power supply to be lower than the normal charging management circuit. In this case, the charging efficiency will be greatly reduced, and the life of the lithium battery is related to the number of times of charging, such The charging method will also affect the service life of the lithium battery

When the solar battery is used as the power supply, there will be such a situation that the energy of the power supply is insufficient.

[0004] Due to the instability of the output current of the solar cell, the current it provides to the lithium battery is different at different times, which will cause the normal constant current and constant voltage charging management circuit to work abnormally. When the output current of the solar cell reaches the constant current charging When the current capacity of the circuit can be charged; when the solar battery is far below the current capacity of the constant current charging circuit, the charging will be turned off and the rechargeable battery cannot be charged

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