Electric fans are used to move air across vehicle engine and/or air conditioning heat exchangers (radiators) at low speeds or while the vehicle is stopped in traffic. Upon achieving ~25 to 35mph the fans are shut off due to incoming air to the radiator from vehicle movement has more volume than fans can generate. After cut-off, the fans spin uselessly in the airstream flowing past the radiators. This concept intends to use the electric fans, when not being used to move air across the heat exchangers, to harvest the incoming air at normal vehicle speeds to generate electricity to help keep vehicle battery systems charged.