Method and device for charging battery pack in an equalizing way

Abstract

The invention provides a method and a device for charging a battery pack in an equalizing way, wherein the method comprises the following steps: detecting the charged electric quantity of each battery of the battery pack when all batteries of the battery pack reach same voltage in the process of charging the battery pack; computing the difference value of the charged electric quantity of each battery and the charged electric quantity of the battery which first reaches the same voltage so as to obtain the deviated charging quantity of each battery; comparing the deviated charging quantity and the equalized charging starting threshold value of each battery; and independently charging the batteries of the battery pack, the deviated charging quantity of which is more than or equal to the equalized charging starting threshold value. The device comprises a charging unit, a detecting unit, a computing unit and a comparing unit. The method and device for charging the battery pack in the equalizing way have accurate selection of equalized charging targets and high reliability of the control process.

Description

technical field [0001] The invention relates to battery charging, in particular to a method and device for equalizing battery charging. Background technique [0002] The voltage and capacity of a single battery are limited. In applications, multiple battery cells are generally connected in series to be used as a battery pack. The series battery pack is widely used in devices such as hybrid vehicles. However, there are more or less differences between each battery cell in the series-connected battery pack, and these differences cause the problem of the balance of the battery pack. For example, the self-discharge rate of each battery is different, and the battery with more self-discharge will first reach the lower limit of the battery capacity during the discharge process, that is, the discharge protection condition will be triggered first, which will reduce the effective capacity of the entire battery pack and also reduce the battery capacity. It will affect the service life...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims at the problem that the equal charging method and device in the prior art cannot intuitively reflect the difference of the electric quantity of each battery in the charging process, and it is easy to misjudge the equal charging target, and provides a battery pack equal charging method and device, the method and device Because the equalizing charging process is controlled based on the offset charging amount, it is more intuitive to reflect the difference in the amount of battery charge when the charging process reaches the same voltage, and it is not easy to cause misjudgment. The advantages of more reliable control of the equalization charging process

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