Battery pack and remaining battery power calculation method

• US 20050127877A1
• Filed: 11/12/2004
• Published: 06/16/2005
• Est. Priority Date: 11/14/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tsuchiya, Yukio, Nagashima, Osamu, Sato, Hideyuki
• Granted Patent: US 7,514,902 B2
• Time in Patent Office: Days
• US Class Current: 320/132
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 50/204 Racks, modules or packs for multiple batteries or multiple cells
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

To reduce calculation errors of remaining battery power so as to take into account capacity diminutions due to cycle degradation and temperature, a remaining power calculation means specifies a temperature correction value for calculation of remaining battery power corresponding to temperature, from among temperature correction values changed every predetermined number of charge/discharge cycles stored in correction value storage means, on the basis of a temperature of a battery cell measured by a temperature measurement means and the number of charge/discharge cycles counted by charge/discharge counting means, and calculates remaining battery power corresponding to the specified temperature correction value. Temperature correction values changed every predetermined number of charge/discharge cycles are used instead of setting different temperature correction values for all charge/discharge cycles, whereby correction of remaining battery power based on cycle degradation and temperature is performed with a small number of parameters.

Claims

1. A battery pack for calculating a remaining battery power according to a number of charge/discharge cycles and temperature during operation, comprising:

temperature measurement means for measuring temperature of a battery cell;

charge/discharge cycle counting means for counting a number of charge/discharge cycles;

correction value storage means for storing correction values changed at every predetermined number of charge/discharge cycles, for calculating the remaining battery power corresponding to the temperature; and

remaining power calculation means for specifying a temperature correction value by searching the correction value storage means based on the measured temperature and the counted number of charge/discharge cycles, and calculating the remaining battery power corresponding to the specified temperature correction value.

2. The battery pack according to claim 1, wherein the correction value comprises a value which is changed at every number of cycles of charge/discharge according to characteristics of capacity change that occurs in response to the temperature and the number of charges/discharges of the battery cell.

3. The battery pack according to claim 1, further comprising a communications means for communicating the calculated remaining battery power amount to a connected device.

4. A remaining battery power calculating method of calculating a remaining battery power according to a number of charge/discharge cycles and temperature during operation, comprising the steps of:

measuring temperature of a battery cell;

specifying a temperature correction value for calculating a remaining battery power corresponding to the measured temperature, wherein said value is changed at every predetermined number of charge/discharge cycles based on the measured temperature and the current number of charge/discharge cycles; and

calculating the remaining battery power corresponding to the correction value.