NOVELTY - The apparatus has a spring (12) e.g. leaf spring, in mechanical communication with a drive train of a motor vehicle. A coupler (14) selectively couples and decouples the spring with the drive train. A control arrangement is arranged with a controller and a sensor, where the sensor senses acceleration and deceleration of the motor vehicle. The controller is operable to operate the coupler such that the spring is compressed by the coupler when the sensor senses the deceleration and the spring is decompressed if the sensor senses the acceleration.    USE - Regenerative braking apparatus for a motor vehicle such as internal combustion type vehicle, hybrid motor vehicle or pure electrically powered vehicle.    ADVANTAGE - The controller can operably connect directly to a motor vehicles electronic control unit (ECU) and utilize the sensors and data collection systems of the motor vehicle to operate a remainder of the apparatus, thus allowing for the more cost effective retrofit of the apparatus by utilizing sensor systems of the motor vehicle. The spring is allowed to decompress in a linear direction by a servo meter such that a support plate moves along the linear direction and a lead screw rotates about angular direction to ultimately return energy to a drive shaft of the motor vehicle, thus requiring less energy from combustion to propel the vehicle. The apparatus reduces the need to charge batteries of the hybrid or purely electric vehicle from an external source and avoids the need for rapid on/off charge cycle by incorporating various energy storage mediums, thus maximizing the efficiency of the apparatus.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for storing and releasing energy generated during deceleration of a motor vehicle.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a coupler of a regenerative braking system.    Spring (12)    Coupler (14)    Shaft (30)    Output gearing (36)    Pawl mechanism (60)