( b ) Electric Vehicle II ( EV-II ) : A road transport vehicle whose drive-train consists of one or more electric motors that receive their energy from one or more batteries that are charged by an on-board internal combustion engine that is not connected to the vehicle drive-train ; ( c ) Hybrid Electric Vehicle I ( HEV-I ) ; A road transport vehicle whose drive-train incorporates a combination of electric motors and an internal combustion engine that powers an electric generator to charge the batteries and also provides direct motive power to the drive-train on demand ; ( d ) Hybrid Electric Vehicle II ( HEV-II ) : A road transport vehicle whose permanent internal combustion drive train can be supplemented by electric motors ; ( e ) Internal Combustion Engine Vehicle ( ICEV ) : A road transport vehicle whose operation relies entirely upon an internal combustion engine to power its drive-train ;