Remaining time calculation device and remaining time calculation method

摘要

PPROBLEM TO BE SOLVED: To provide a technology of precisely calculating the remaining time of a secondary battery. PSOLUTION: A remaining capacity detection part 212 detects the remaining capacity RC of a battery pack 14. An average voltage information storage part 213 pre-stores the average voltage information showing an average voltage of a battery pack 14 obtained when a constant electric power is discharged from the battery pack 14. In a correction part 214, the average voltage Vave corresponding to a discharge current Idc detected by a current detection resistance 16 and a temperature detected by a temperature sensor 17 are determined by referring to the average voltage information, and the remaining capacity RC is corrected based on the ratio of the average voltage Vave of the battery pack 14 to the voltage V detected by a voltage detection circuit 15. A remaining time calculation part 215 calculates the remaining time T of the battery pack 14 by dividing ImCapa calculated by the correction part 214 by the discharge current Idc detected by the current detection resistance 16, that is, by the arithmetic operation of formula (2). PCOPYRIGHT: (C)2011,JPO&INPIT