Abstract: There is provided a battery pack capable of supplying a stable output and of being charged stably in a low temperature environment (for instance, 0° C. or lower). A battery pack (1) includes: a battery group (11) having a first battery (10A) and a second battery (10B) disposed around the first battery (10A); and a heater (14) that is disposed on an outer peripheral side of the battery group (11), famed by the second battery (10B), and that generates heat by being energized by the first battery (10A). The first battery (10A) is allowed to be charged and discharged with a higher current than a current of the second battery (10B) in a temperature range lower than or equal to a predetermined temperature.

Abstract: The method of charging a battery array performs constant current, constant voltage charging of a battery array while detecting the voltage of each battery. The battery array is a plurality of series connected batteries. The charge method detects the voltage of each battery cell at a prescribed sampling rate. When the voltage of any battery cell exceeds a preset maximum specified voltage, charging power is reduced for constant current, constant voltage charging of the battery array.

Abstract: The method of charging a battery array performs constant current and constant voltage charging of a battery array while detecting the voltage of each battery. The battery array is a plurality of series connected batteries. The charge method detects the voltage of each battery cell at a prescribed sampling rate. When the voltage of any battery cell exceeds a preset maximum specified voltage, charging power is reduced for constant current, constant voltage charging of the battery array.

Abstract: The method of charging a battery array performs constant current and constant voltage charging of a battery array while detecting the voltage of each battery. The battery array is a plurality of series connected batteries. The charge method detects the voltage of each battery cell at a prescribed sampling rate. When the voltage of any battery cell exceeds a preset maximum specified voltage, charging power is reduced for constant current, constant voltage charging of the battery array.

Abstract: The method of charging a battery array performs constant current, constant voltage charging of a battery array while detecting the voltage of each battery. The battery array is a plurality of series connected batteries. The charge method detects the voltage of each battery cell at a prescribed sampling rate. When the voltage of any battery cell exceeds a preset maximum specified voltage, charging power is reduced for constant current, constant voltage charging of the battery array.

Abstract: A charging operation controlling portion controls charging current or charging voltage when the battery pack 440 is charged with electric power generated by the solar panel 410. The current detecting portion 456 detects charging current of the battery pack. The voltage detecting portion 455 detects battery voltage of the battery pack. The charging operation controlling portion, when the battery pack 440 is brought close to the fully-charged state, cuts off the charging current at predetermined timing for a charging operation stop period, and compares the battery voltage of the battery pack 440 with a predetermined voltage value as a restart voltage value in the charging operation stop period. The charging operation controlling portion determines that the battery pack 440 is fully charged if the battery voltage of the battery pack 440 is not less than the predetermined voltage value as the restart voltage value, and cuts off the charging current.

Abstract: The method of charging a battery array performs constant current, constant voltage charging of a battery array while detecting the voltage of each battery. The battery array is a plurality of series connected batteries. The charging method detects the voltage of each battery cell at a prescribed sampling rate. When the voltage of any battery cell exceeds a preset maximum specified voltage, charging power is reduced for constant current, constant voltage charging of the battery array.

Abstract: A method for charging a lithium-ion secondary battery is so designed as to fully charge, with a voltage of the lithium-ion secondary battery being limited to a set voltage. Further, the method for charging the lithium-ion secondary battery is so designed that a degradation level of the lithium-ion secondary battery is detected, and when the degradation is advanced, the battery is fully charged with the set voltage being lowered.