Method for charging a battery

• US 5,705,915 A
• Filed: 03/03/1997
• Issued: 01/06/1998
• Est. Priority Date: 03/03/1997
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Williams, William R., Geren, Michael D., Douglas, Twanika D., Patino, Joseph
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/805,836
• Time in Patent Office: 309 Days
• Field of Search: 320/5, 320/21, 320/29, 320/30, 320/31, 320/35, 320/36, 320/37, 320/38
• US Class Current: 320/152
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/007184 in response to battery voltage gradient
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method for charging a battery or battery pack (206) provides a scheme for terminating a rapid charging regime only after both a temperature and voltage threshold are exceeded. This allows a battery to continue to receive a rapid charge even when battery temperatures are rising rapidly due to external (non-charge related) conditions.

Claims

1. A method of charging an electrochemical cell comprising the steps of:

determining an initial cell temperature and voltage level;

initiating a rapid charging regime;

measuring the temperature of the cell at regular intervals after initiating said rapid charging regime to determine temperature increases in said cell between each regular interval;

measuring battery voltage if the temperature increase in any one regular interval exceeds a preselected temperature threshold value; and

terminating said rapid charging regime if the measured battery voltage exceeds a preselected voltage threshold value.

2. A method as in claim 1, wherein battery temperature is measured at three minute intervals.

3. A method as in claim 1, wherein battery voltage is measured when the temperature increase for any one regular interval exceeds 1.6°

C.

4. A method as in claim 1, wherein the preselected voltage threshold value is between 9 and 10 volts.

5. A method of determining the endpoint of a rapid charging regime for a battery cell in a battery charging device, said method comprising the steps of:

measuring temperature increase of said battery cell at regular intervals during said rapid charging regime;

measuring battery voltage if the temperature increase of said battery during any regular interval exceeds a preselected temperature threshold value; and

terminating the rapid charging regime if the measured battery voltage exceeds a preselected voltage threshold value.

6. A method as in claim 5, wherein battery temperature is measured at three minute intervals.

7. A method as in claim 5, wherein battery voltage is measured when the temperature increase for any one regular interval exceeds 1.6°

C.

8. A method as in claim 5, wherein the preselected voltage threshold value is between 9 and 10 volts.