Charging method of power battery of electric vehicle

Abstract

The invention provides a charging method of a power battery of an electric vehicle. The charging method comprises the following steps: S1, detecting the maximal temperature and the minimal temperature of a battery, and judging whether the minimal temperature is lower than a first threshold temperature or not, if so, executing a step S2; if not, continuing to judge whether the minimal temperature is higher than a second threshold temperature or not, if so, executing a step S4, if not, executing a step S3; S2, entering a pure-heating mode; S3, entering a charging and heating mode; and S4, entering a pure-heating mode. According to the charging method of the power battery of the electric vehicle, provided by the invention, the power battery at low temperature is charged, the power battery enters different charging procedures according to the minimal temperature of the battery, namely, the pure-charging mode, the heating and charging mode and the pure-charging mode, so that the low-temperature charging and heating time can be shortened, and the rapid charging of the battery is ensured.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a charging method for a power battery of an electric vehicle. Background technique [0002] Lithium iron phosphate batteries have many advantages, such as long service life, large capacity, high current charge and discharge, etc. Therefore, lithium iron phosphate batteries are usually used as power batteries for electric vehicles. In winter in the north, the lithium iron phosphate battery of a pure electric vehicle needs to be heated during charging, and the battery can only be heated after heating to a certain temperature, so the heating time will be very long! During the heating process, often due to the distribution of heating devices and the arrangement of temperature collection points, the internal temperature difference of the battery pack will be very large during the heating process. For the sake of battery protection, the heating method is usually when the temp...

AI Technical Summary

Problems solved by technology

In winter in the north, the lithium iron phosphate battery of a pure electric vehicle needs to be heated during charging, and the battery can only be heated after heating to a certain temperature, so the heating time will be very long! During the heating process, often due to the distribution of heating devices and the arrangement of temperature collection points, the internal temperature difference of the battery pack will be very large during the heating process. For the sake of battery protection, the heating method is usually when the temperature difference is greater than When a certain threshold is reached, the heating and charging process will be stopped, resulting in an extension of the heating and charging time; and the judgment of whether the heating process is completed is based on the lowest temperature. , the lowest temperature is sometimes below 0°C, so the temperature imbalance also prolongs the charging time

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