My traction battery is always fully charged. According to Toyota it can be only 80 % charged and discharged to 20 %. If I did not run it off the EV mode for at least some of the driving I am wasting all the energy of regenerative braking since the extra generated potential energy is not storable. So why not use up the battery power and let it get charged while braking or while my foot is off the accelerator. I can understand if the ICE charges the battery and then the battery via the motor runs the CVT, in which case there is loss of efficiency due to the conversion process. But a traction battery that is fully charged and can absorb no more energy and is not put in use is a dead weight in the vehicle.