The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 20, 1997
Filed:
Oct. 17, 1995
Gene Armstrong, Plano, TX (US);
Benchmarq Microelectronics, Dallas, TX (US);
Abstract
A battery charger/protection device (10) is provided for charging a battery pack (12) comprised of four lithium ion cells. Each of the cells is selectively monitored by examining the voltage thereacross. An overvoltage condition is checked for a cell, an undervoltage condition for a cell is checked and an overcurrent condition for the entire battery pack (12) is checked. This is achieved by comparing the voltage with predetermined threshold voltages during the charging operation. This is a sequential operation wherein each of the batteries is sequentially examined in a continuous manner through the charging operation in accordance with a predetermined scheme. Switches (30) and (28) are provided for terminating a charging operation during charging. During operation, the undervoltage condition can be checked and the charger/protection device (10) placed in a sleep mode. The charger/protection device (10) provides a finite number of terminals for accessing any combination of cells. By connecting the terminals together for an unused cell, information about the cell across those two terminals can be nullified by indicating that no cell is present and that a short has been substituted for the cell, information about this cell then not utilized in the charging monitoring operation. This allows a single part to accommodate different batteries.