In-vehicle power storage device and control method thereof

A method for controlling an in-vehicle power storage device that includes:

• a battery mounted in a vehicle and comprising a plurality of battery cells;
• battery charge-state detector for detecting a charge state of the battery;
• and a discharging load for discharging the battery, the method comprising:
• a first operation of emergency discharging the battery by using the load in a case where collision of the vehicle is detected or predicted;
• a second operation of determining whether an abnormality of the battery has occurred, while the emergency discharging is performed but before the battery is discharged to a predetermined value higher than a near-zero value;
• a third operation of stopping the emergency discharging of the battery which is being performed in the first operation when the overall charge state of the battery comprising the plurality of battery cells becomes less than or equal to the predetermined value;
• a fourth operation of, in a case where the abnormality of the battery is detected during said second operation of emergency discharging, discharging the battery until the overall charge state of the battery comprising the plurality of battery cells represents the near-zero value, without stopping discharging the battery when the overall charge state of the battery becomes less than or equal to the predetermined value;
• and
• a fifth operation of providing external notification of said emergency discharging,
• wherein, when the collision of the vehicle is detected or predicted, the first operation of emergency discharging the battery is started before the second operation of determining whether the abnormality of the battery has occurred, is completed, and performing the third operation of stopping the emergency discharging of the battery before the battery enters an overdischarged state, when the abnormality of the battery does not occur.

An in-vehicle power storage device comprising:

• a battery mounted in a vehicle and comprising a plurality of battery cells;
• battery charge-state detector which detects a charge state of the battery;
• and a discharging load for discharging the battery, the in-vehicle power storage device further comprising a control device, the control device including:
• a battery discharger which, upon detection of a first problem, begins an emergency discharge operation by which said load is used to discharge said battery until the overall charge state of the battery comprising the plurality of battery cells becomes a first charge state, said battery discharger continuing discharge of said battery past said first charge state in response to a second problem detected after commencement of said discharge operation, said discharge operation terminating at said first charge state when said second problem is not detected during said discharge operation;
• and
• a notifier providing external notification of said emergency discharge,
• wherein the battery discharger determines whether an abnormality of the battery has occurred, while the emergency discharge operation is performed but before the battery is discharged to a predetermined value higher than a near-zero value, and
• wherein, when the collision of the vehicle is detected or predicted, the battery discharger starts discharging the battery before a determination of whether the abnormality of the battery has occurred, is completed, and stops discharging the battery before the battery enters an overdischarge state, when the abnormality of the battery does not occur.