Battery SOH testing device based on charger and method for testing battery SOH

The invention belongs to the field of new-energy electric vehicle charging technology, and relates to a battery SOH testing device based on a charger and a method for testing battery SOH. In testing the battery SOH, a monitoring module controls a controller so that the charger performs switching between a discharging mode and a charging mode. The monitoring module transmits discharging instruction or charging instruction so that the battery is discharged or charged. The charger acquires data of the charging process or the data of the discharging process and calculates the dischargeable capability of the battery according to the acquired data, and furthermore obtains the battery SOH. The battery SOH testing device and the method for testing battery SOH have advantages of realizing simplest and most accurate testing on battery SOH in a discharging testing method, eliminating a defect of low accuracy in pre-estimating the SOH by a BMOS, ensuring high prediction accuracy for the automobile SOC, improving user experience, and supplying battery maintenance guidance for a user. Furthermore, the battery SOH testing device and the method change a condition that the charger only has one charging function and realize recycling on the discharged energy of the electric vehicle battery. Furthermore high economic benefit is realized.