A smart battery device (10) which provides electrical power and which reports predefined battery parameters to an external device having a power management system, includes: at least one rechargeable cell (26) connected to a pair of terminals (37 and 32) to provide electrical power to an external device (28) during a discharge mode, and to receive electrical power during a charge mode, as provided or determined by remote device (28); a data bus for reporting predefined battery identification and charge parameters to the external device; analog devices for generating analog signals representative of battery voltage and current at the terminals, and an analog signal representative of battery temperature at the cell; a hybrid integrated circuit (32) having a microprocessor (50) for receiving the analog signals and converting them to digital signals representative of battery voltage, current and temperature, and calculating actual charge parameters over time from the digital signals, the calculations including one calculation according to the following algorithm: CAPrem = CAPFC - SIGMA Id DELTA ta - SIGMA Is DELTA ts + SIGMA ELEMENT cIc DELTA tc wherein ELEMENT c is a function of battery current and temperature; and Is is a function of battery temperature and CAPpc. Superimposed on this equation is reset logic, that self corrects the CAPFC with a capacity calculation at each full charge (EOC) and each end of full discharge.

Title
Smart battery device
Application Number
95196743
Publication Number
1169797
Application Date
November 8, 1995
Publication Date
January 7, 1998
Inventor
Elmar Zeising
Rudi Wieczorek
Phuoc Van Duong
Agent
JIAN WEI
Assignee
Duracell
IPC
H01M 10/44
H01J 07/04