Charging control method and system of lithium ion battery pack

Abstract

The invention discloses charging control method and system of a lithium ion battery pack, wherein the method comprises the following steps of: charging the lithium ion battery pack through a constant-current value after starting charging, monitoring the voltage of each monomer battery in real time in the whole charging process, and carrying out equalizing charging on a battery with the voltage lower than a mean value by taking the energy from the battery with the voltage higher than the mean value; when the highest voltage of the monomer battery reaches an upper limit value, converting a charging mode, and carrying out constant-voltage charging on the battery pack through the current voltage value of the battery pack; and when the highest voltage of the monomer battery is lower than the resetting value of the preset upper limit value, gradually increasing the charging voltage through preset voltage step length delta V until the voltage of the lithium ion battery pack reaches a preset constant-voltage value, and when the charging current of the lithium ion battery pack is decreased to a preset charging current end value, ending the charging. The system comprises a battery management system, charging equipment and an equalizing unit. Through the invention, the actual charging capacity of the lithium ion battery pack can reach the designed capacity under the condition of ensuringno overcharging.

Description

technical field [0001] The invention relates to battery charging technology, in particular to a charging control method and system for a lithium-ion battery pack. Background technique [0002] Lithium-ion batteries have the advantages of high specific energy, small size, and long cycle life, but they are very sensitive to charging voltage. During charging, once the charging voltage exceeds its allowable value, not only will the service life of lithium-ion batteries be shortened, but in severe cases It may also cause accidents such as burning and bursting. [0003] In practical applications, multiple lithium-ion batteries are usually connected in series to obtain a higher output voltage. For ease of use, a charging device is generally used to charge the entire set of batteries. Limited by the manufacturing process of lithium-ion batteries, there are certain differences between single lithium-ion batteries. Although this difference can be reduced by selecting methods, as the...

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Problems solved by technology

[0005] The invention provides a charging control method and system for a lithium-ion battery pack, which is used to solve the problems in the prior art that the charging current of the lithium-ion battery pack cannot be too large and the actual charging capacity of the lithium-ion battery pack is lower than the design capacity

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