Method and apparatus for controlling battery charging in a hybrid electric vehicle

A system for an automotive vehicle comprising:

• an internal combustion engine;
• an energy storage device;
• a starter/alternator coupled to the engine;
• a controller coupled to the starter/alternator and to the energy storage device, said controller monitors a state of charge of the energy storage device, a plurality of threshold levels are established for controlling charging of the energy storage device, said controller compares the state of charge to the threshold levels to determine the operation of the starter/alternator, wherein a first threshold of said plurality of threshold levels comprises an engine run threshold, a second threshold of said plurality of threshold levels comprises a boost off threshold and a third threshold of said plurality of threshold levels comprises an engine off threshold, wherein said first threshold is less than said second threshold, said second threshold less than said third threshold.

A system for an automotive vehicle comprising:

• an internal combustion engine;
• an energy storage device;
• a starter/alternator coupled to the engine;
• a controller coupled to the starter/alternator and to the energy storage device, said controller monitors a state of charge of the energy storage device, a plurality of threshold levels are established for controlling charging of the energy storage device, said controller compares the state of charge to the threshold levels to determine the operation of the starter/alternator, wherein a fifth threshold of said plurality of threshold levels comprises a charge on threshold, a sixth threshold of said plurality of threshold levels comprises a charge_off threshold and, a seventh threshold of said plurality of threshold levels comprises a bleed off threshold, wherein said fifth threshold is less than said sixth, said sixth threshold less than said seventh threshold.

A system for an automotive vehicle comprising:

• an internal combustion engine;
• an energy storage device;
• a starter/alternator coupled to the engine;
• a controller coupled to the starter/alternator and to the energy storage device, said controller monitors a state of charge of the energy storage device, a plurality of threshold levels are established for controlling charging of the energy storage device, said controller compares the state of charge to the threshold levels to determine the operation of the starter/alternator, wherein a seventh threshold of said plurality of threshold levels comprises a bleed off threshold and an eighth threshold of said plurality of threshold levels comprises a regenerative braking off threshold, wherein said seventh threshold is less than said eighth threshold.

A method of charging a battery in a hybrid electric vehicle having a starter/alternator and a battery having a state of charge comprising the steps of:

• when the state of charge is below a first predetermined value, allowing the charging of the battery through operation of the starter/alternator as a generator;
• and
• when the state of charge is above a second predetermined value, allowing the battery to bleed;
• wherein the steps of allowing the charging of the battery and allowing the charging of the battery are mutually exclusive.

A method of charging a battery of a hybrid electric vehicle comprising the steps of:

• when a state of charge of the battery is below a first predetermined value, running the engine until the battery charges above the first predetermined value;
• when the state of charge is below a second predetermined value above the first predetermined value, disabling boost from the battery;
• when the state of charge is above a third predetermined value above the second predetermined value, allowing the starter/alternator to operate as a motor;
• when the state of charge is above a fourth predetermined value above the third predetermined value, disabling the starter/alternator to operate as a generator;
• when the state of charge is above a fifth predetermined value above the fourth predetermined value, bleeding the battery;
• and
• when the state of charge is above a fifth predetermined value above the fourth predetermined value, disabling regeneration of the battery.