1. A method of controlling output torque in a vehicle transmission including at least one electric machine and in electrical communication with a battery, comprising: calculating a first long-term output torque constraint; calculating a first short-term output torque constraint; determining a first effective output torque constraint from at least one of the first long-term output torque constraint and the first short-term output torque constraint, wherein the first effective output torque constraint is bounded by both of the first long-term output torque constraint and the first short-term output torque constraint; and operating the transmission at the first effective output torque constraint.