State of charge control method and systems for vehicles

A method for increasing the charging capacity of a battery that provides energy to propel a vehicle, comprising:

• establishing an upper state of charge limit in a vehicle battery control system;
• establishing a lower state of charge limit in the vehicle battery control system, the upper and lower limit defining a state of charge range;
• setting a target state of charge value in the vehicle battery control system to less than the midpoint of the state of charge range such that the target state of charge value does not change based upon predicted vehicle driving conditions;
• and
• configuring the vehicle battery control system to charge the battery state of charge to the upper limit through regenerative braking and to discharge the battery state of charge toward the lower target state of charge limit by engaging an electric motor.

A system for controlling a state of charge in a vehicle battery, comprising:

• an electric motor operative to propel the vehicle;
• a battery electrically coupled to the electric motor;
• and
• a battery control system, the battery control system having a predetermined state of charge range defined by an upper state of charge limit, the upper state of charge limit defining a maximum battery charge that should not be exceeded, and a lower state of charge limit, the lower state of charge limit defining a minimum battery charge to be maintained, the battery control system also having a target state of charge permanently set to less than the midpoint of the state of charge range, the battery control system including:
• a controller operative to maintain the battery state of charge within the range and regulate the battery state of charge to the target state of charge value.