Method and apparatus including a current detector and a power source control circuit for charging a number of batteries

Patent 5557189 Issued on September 17, 1996. Estimated Expiration Date:

December 9, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

System and method for charging electrochemical cells in series
Patent #: 4238721
Issued on: 12/09/1980
Inventor: DeLuca , et al.

Charging regulator
Patent #: 4614905
Issued on: 09/30/1986
Inventor: Petersson , et al.

Battery charging apparauts Patent #: 5387857
Issued on: 02/07/1995
Inventor: Honda, et al.

Inventors

Assignee

Sony Corporation

Application

No. 352618 filed on 12/09/1994

US Classes:

320/119, With individual charging of plural batteries or cells320/120Having variable number of cells or batteries in series

Examiners

Primary: Wong, Peter S.
Assistant: Law, Patrick B.

Attorney, Agent or Firm

Maioli; Jay H.

International Classes

H01M 010/44
H01M 010/46

Foreign Application Priority Data

1993-12-24 JP

Abstract

A battery charging apparatus for charging the electricity from a current source to a cell includes a variable resistor in parallel with the cell, a cell voltage detection unit for detecting the current voltage value of the cell and a comparator for comparing the current voltage value to a pre-set voltage value. The resistance value of the variable resistor is controlled responsive to the results of comparison so that the current from the current source is caused to flow through both the cell and the variable resistor with progress in the charging of the cell. The current is prevented from flowing through the cell when the cell is fully charged, so that overcharging is eliminated. If plural cells are charged in series, the control operation of not causing the current to flow through the fully charged cell can be carried out for each of the cells, so that integrated charging may be continued until all of the cells are fully charged thus shortening the cell charging time.