Sanyo Electric Co., Ltd.

Atsushi Kawasumi

Toru Nishikawa

Shinichi Matsuura

Kenichi Kobayashi

Toru Morioka

Shinichi Itagaki

Hitoshi Hamaguchi

The battery pack is provided with an analog front-end that detects battery voltage, and a micro-controller connected to the analog front-end that accepts analog voltage signals from the analog front-end as input. The micro-controller switches voltage signals input from the analog front-end to determine failure of the analog front-end or the micro-controller.

Battery pack

A remaining capacity calculating section is provided that acquires a discharged capacity of a rechargeable battery based on a discharging current and a discharging time of the rechargeable battery, and calculates a relative remaining capacity of the rechargeable battery based on the discharged capacity and the fully-charged capacity of the rechargeable battery. The remaining capacity calculating section employs the rating capacity of the rechargeable battery or a learned fully-charged capacity as the fully-charged capacity when a high capacity mode is selected, and employs a capacity obtained by multiplying the rating capacity or learned fully-charged capacity by a predetermined factor not more than 1 as the fully-charged capacity when a long life mode is selected.

Battery pack capable of calculating relative remaining capacity

A battery pack updating method updates firmware stored in internal control circuit memory via an update signal sent from a main device that supplies power. When battery pack memory is updated, an AC adapter is connected to the main device, and power is supplied to the main device from the AC adapter. The updating method transmits a charging and discharging blocking signal from the main device to the battery pack control circuit via a communication line. The charging and discharging blocking signal stops discharge from the battery pack rechargeable battery, and stops charging of the rechargeable battery. With rechargeable battery discharging and charging to and from the main device stopped by the charging and discharging blocking signal, the updating method transmits update data from the main device to the battery pack control circuit to update memory.

Battery pack updating method

The rechargeable battery abnormality detection apparatus is provided with an internal short circuit detection section () that monitors rechargeable battery () voltage change when no charging or discharging takes place, and detects internal short circuit abnormality when battery voltage drop during a predetermined time period exceeds a preset threshold voltage; a degradation appraisal section () that judges the degree of rechargeable battery degradation; and a threshold control section () that incrementally increases the threshold voltage according to the degree of degradation determined by the degradation appraisal section ().

Rechargeable battery abnormality detection apparatus and rechargeable battery apparatus

A charging method includes first and second charging steps to charge a lithium-ion battery. In the first charging step, a temperature rise gradient of the battery is detected. A battery temperature when the battery is charged to a first predetermined capacity is predicted based on the detected gradient. A charging current is controlled based on the predicted temperature. The battery is charged, at a current that results in a battery temperature that is lower than a predetermined temperature, to the first predetermined capacity. In the second charging step, a temperature rise gradient of the battery is detected. A battery temperature when the battery is charged to a second predetermined capacity is predicted based on the gradient. A charging current is controlled based on the predicted temperature. The battery is charged, at a current that results in a temperature of the battery that is lower than the predetermined temperature, to the second predetermined capacity.

Charging method

A battery pack includes a switching element, a heat resistor, and a fuse. The switching element turns to ON if the battery pack becomes in an abnormal state. The heat resistor is connected to the switching element and a battery in series. Current flows through the heat resistor when the switching element turns to ON. The fuse is located in a position where the fuse is heated by the heat resistor through which the current flows. The fuse is connected to the battery in series so that the fuse is disconnected with heat by the heat resistor at high temperature. Thus, the fuse cuts off a current flow in the battery. If the battery pack is in an abnormal state, when the capacity or voltage of the battery is less than a preset capacity or voltage value, the fuse is disconnected with heat by turning the switching element to ON.

Method for controlling battery pack

A battery pack provided with a current cut-off device connected in series with batteries, a tamper detector to detect tampering and issue a tamper signal, and a control circuit connected to the tamper detector. If the tamper detector detects tampering with the battery pack, the control circuit switches the current cut-off device off to shut off current to the batteries, or it issues a tamper signal.

Growing community of inventors

Sumoto, Japan

Atsushi Kawasumi