Patent ID: 7761198

Claim:
An energy management system for a vehicle comprising: a first power source configured for cranking an engine, said first power source comprising a switch configured to electrically couple the first power source to a starter for the engine, said first power source electrically isolated from auxiliary onboard loads; an essential bus connected to said first power source; a second power source configured for supplying power to said auxiliary onboard loads; a non-essential bus connected to said second power source; a charging subsystem electrically coupled to said first and said second power sources, said charging subsystem configured to supply charging current to said first and said second power sources; a power transfer device configured to selectively connect said essential bus and said non-essential bus; and a controller configured to: maintain said first power source in a substantially fully charged condition; predict a length of time said second power source is capable of supplying power at a present determined rate to a non-essential onboard load; determine a sequence and timing of disconnecting non-essential auxiliary onboard loads from said second power source; supply power to said auxiliary onboard loads from said second power source and disconnect said non-essential auxiliary on-board load from said second power source using the determined sequence and timing; and supply power to a portion of said auxiliary onboard loads through said essential bus from said second power source using said power transfer device and configured to supply power to a remaining portion of said auxiliary onboard loads through said non-essential bus and wherein said controller is further configured to disconnect said non-essential bus from said second power source after a predetermined amount of electrical discharge from said second power source.