Method and apparatus of determining performance for battery for mild hybrid electric vehicle

An apparatus for determining performance of a battery for a mild hybrid electric vehicle, the apparatus comprising:

• a mild hybrid starter and generator engine (MHSG) for starting an engine or generating electricity according to an output of the engine;
• a battery supplying electricity to the MHSG and charged with electricity recovered through the MHSG;
• a vehicle speed sensor for detecting a speed of the mild hybrid electric vehicle;
• an accelerator pedal position sensor for detecting a position value of an accelerator pedal;
• a brake pedal position sensor for detecting a position value of a brake pedal;
• a state of charge (SOC) sensor for detecting an SOC of the battery;
• and
• a controller for determining performance of the battery based on the speed of the mild hybrid electric vehicle, the position value of the accelerator pedal, the position value of the brake pedal, and the SOC of the battery,
• wherein the controller determines a demand braking amount of a driver when a regenerative braking condition is satisfied, determines a regenerative braking allowance based on the demand braking amount of the driver and the SOC of the battery, operates the MHSG to generate regenerative braking torque corresponding to the regenerative braking allowance, determines a target SOC increment amount corresponding to the regenerative braking allowance, determines an actual SOC increment amount based on the SOC of the battery, and determines that the performance of the battery is deteriorated when a difference value between the target SOC increment amount and the actual SOC increment amount is equal to or greater than a reference value.