Secondary protection circuit for charging and discharging hardware of lithium ion battery

Abstract

The invention relates to the technical field of lithium batteries, and discloses a secondary protection circuit for charge and discharge hardware of a lithium ion battery. The secondary protection circuit comprises a threshold comparator and a logic control circuit, wherein the threshold comparator comprises a first operational amplifier and a second operational amplifier, the logic control circuit comprises a charge control driving circuit and a discharge control driving circuit, the charge control driving circuit comprises a GP_CO input end and a CO_CP input end, the discharge control driving circuit comprises a DO_CP input end and a GP_DO input end, the GP_CO input end and the GP_DO input end are electrically connected with an I / O pin of a CPU main control chip and serve as a charge anddischarge logic protection outlet of a software program of the CPU main control chip, the CO_CP input end and the DO_CP input end are electrically connected with the output end of the first operational amplifier and the output end of the second operational amplifier of the threshold comparator respectively and serve as a charge and discharge logic protection outlet of the hardware. According to the technical scheme, the probability of risks such as combustion and explosion caused by overcharge and overdischarge in the using process of the lithium battery can be greatly reduced, and the secondary protection circuit has high practical value in the application occasions of low-voltage and low-string-number lithium batteries.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a lithium ion battery charging and discharging hardware secondary protection circuit. Background technique [0002] In the current market, in low-voltage applications such as electric robots, electric tools, and mobile power supplies, 3 to 6 strings of lithium-ion batteries with a low number of strings are widely used. The charging and discharging operating voltage, current, and temperature of lithium-ion batteries must be strictly controlled within the set limits. Only within the range can the safe use of the battery be guaranteed. At present, there are two main control schemes for the monitoring and protection of this low-series lithium-ion battery: one is to use a dedicated battery protection IC. And external capacitors to realize protection logic and delay functions such as battery overcharge, overdischarge, overcurrent, overtemperature and short circuit, etc. fig...

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