Chinese auto giant Chery is recalling more than 20,000 electric vehicles (EVs) produced several years ago, in a rare recall of EVs by a local automaker.

Effective immediately, Chery is recalling a total of 20,063 Chery eQ1 EVs with production dates between December 3, 2016 and February 9, 2018.

Due to a software strategy issue in the battery system, after frequent fast charging or parking for a long period of time, the pressure difference between the power battery cells inside the recalled vehicles gradually becomes larger.

When the pressure difference of the cells exceeds the design value, it may lead to power limitation when the vehicle is traveling, and in extreme cases, the high-voltage system may be disconnected, thus making the vehicle lose power.

Chery will upgrade the battery management system software of the recalled vehicles free of charge to eliminate the safety hazard.

Chery's recall of EVs is a rare case among local Chinese automakers. Previous recalls of EVs in China were mostly seen by foreign car companies, such as BMW, Mercedes-Benz and Tesla, which have all conducted several recalls in China this year.

Chery Group sold a record 150,466 vehicles in July, up 14.4 percent year-on-year, marking the 14th consecutive month of sales of more than 100,000 vehicles, according to data it released earlier this month. From January to July, Chery Group sold 891,895 vehicles, up 47 percent from a year earlier.