Dynamic allocation of energy storage limits for a hybird vehicle propulsion system

A method of operating a hybrid propulsion system for a vehicle including at least an engine having a plurality of combustion cylinders, wherein the engine is configured to deactivate at least one combustion cylinder, wherein the engine is mechanically coupled to at least a drive wheel of the vehicle;

• an energy conversion device mechanically coupled to at least one of the engine and the vehicle drive wheel;
• and an energy storage device coupled to the energy conversion device, the method comprising:
• varying a number of deactivated combustion cylinders;
• and
• adjusting at least one of the engine and the energy conversion device so that an amount of energy stored by the energy storage device varies within a first range when the engine is operating with a first number of deactivated combustion cylinders and varies within a second range when the engine is operating with a second number of deactivated combustion cylinders, wherein the first range is different from the second range.