Charging and discharging protection circuit for multiple serial lithium battery

Abstract

The present invention provides a charge-discharge protection circuit of a multiple-section series Li-ion battery, including at least two section Li-ion battery mutually serial connection in orders, an external connective load and a charge power; characterized in that two ends of each section Li-ion battery is accordingly connected with a sampling circuit and a signal conversion circuit, further including a public execution circuit. The invention fully applies the single-section Li-ion battery protection chip, each Li-ion battery is matched with a single-section Li-ion battery protection chip, forming an unit circuit by matching with a fet; each unit circuit includes a sampling circuit and a signal conversion circuit, for monitoring voltage of each single Li-ion battery and output control signal; the charge-discharge voltage and the current of each single Li-ion battery is wholly controlled by the execution circuit which core is the fet, only when the working voltage of the single Li-ion battery is too high and low, or the working current of the Li-ion battery is too high, the charge or discharge of the circuit is closed, achieving the aim of the protecting the Li-ion battery.

Description

technical field [0001] The invention relates to a charging and discharging protection circuit of a lithium battery, in particular to a charging and discharging protection circuit in which two or more than two lithium batteries are connected in series. Background technique [0002] Lithium batteries are widely used as rechargeable batteries for various portable or mobile products such as mobile phones and electric tools because they have higher power capacity and lighter power quality than conventional nickel-cadmium batteries and nickel-metal hydride batteries. During the use of rechargeable batteries, overcharge, overdischarge and overcurrent will affect the service life and performance of the battery. For safety design, the battery cells, especially lithium-ion cells, must be equipped with a protective plate to prevent overcharge, over Burning, explosion and other dangers caused by discharge and short circuit. [0003] At present, major IC design companies in the world, s...

AI Technical Summary

Problems solved by technology

The above-mentioned patent overcomes the problem that traditional and existing integrated protection chips cannot control the charging and discharging protection of multiple lithium batteries connected in series, but the current detection module used in the circuit is an independent circuit, and a single-chip microcomputer is also required to control discharging and charging The switch and the circuit involve many components, high cost, complicated connection, and the single-chip microcomputer itself consumes a certain amount of power, which causes the lithium battery to lose its capacity after being placed for a long time and be scrapped

Images