Claims
- 1. A charging circuit for determining an onset of an overcharge phase of a battery during a charging cycle, the battery having a battery temperature, and the charging circuit comprising:
- a first temperature sensor coupled to measure the battery temperature;
- a second temperature sensor that provides a control temperature; and
- processing circuitry that identifies the overcharge phase onset of the battery based on a corrected battery temperature and measurements from the first and second temperature sensors.
- 2. The charging circuit of claim 1 further comprising an insulator that separates the first temperature sensor and the battery from the second temperature sensor.
- 3. The charging circuit of claim 1 wherein the processing circuitry identifies the onset by determining whether an actual rate of change in battery temperature is beyond an acceptable rate of change.
- 4. The charging circuit of claim 3 wherein the acceptable rate of change is based on an anticipated rate of change.
- 5. The charging circuit of claim 4 wherein the processing circuitry determines the anticipated rate of change.
- 6. The charging circuit of claim 1 wherein the processing circuitry ends the charging cycle upon identifying the onset.
- 7. The charging circuit of claim 1 wherein the processing circuitry alters the charging characteristics upon identifying the onset.
- 8. A charging circuit for determining an onset of an overcharge phase of a battery during a charging cycle, the battery having a battery temperature, and the charging circuit comprising:
- a first temperature sensor disposed to measure the battery temperature;
- processing circuitry that couples with the first temperature sensor to determine an actual rate of change in the battery temperature; and
- the processing circuitry determining an acceptable rate of change in the battery temperature.
- 9. The charging circuit of claim 8 wherein the processing circuitry determines the acceptable rate of change based on at least one measurement from the first temperature sensor.
- 10. The charging circuit of claim 8 wherein the acceptable rate of change is based on an anticipated rate of change.
- 11. The charging circuit of claim 10 wherein the processing circuitry determines the anticipated rate of change.
- 12. The charging circuit of claim 10 further comprising a second temperature sensor disposed to provide a reference temperature.
- 13. The charging circuit of claim 12 wherein an insulator separates the first temperature sensor and the battery from the second temperature sensor.
- 14. A method of detecting an onset of an overcharge phase of a battery during a charging cycle, the battery having a battery temperature, and the method comprising:
- identifying an acceptable rate of change in the battery temperature using a predetermined temperature profile;
- determining an actual rate of change in the battery temperature; and
- comparing the acceptable rate of change with the actual rate of change to detect the onset of the overcharge phase.
- 15. The method of claim 14 that utilizes a reference temperature wherein the battery temperature and reference temperature are both used in the process of identifying the acceptable rate of change in battery temperature.
- 16. The method of claim 14 further comprising terminating the charging cycle upon detection of the onset.
- 17. The method of claim 14 further comprising altering charging characteristics upon detection of the onset.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Patent Application having U.S. Ser. No. 08/700,205 filed Aug. 20, 1996 and resulting in U.S. Pat. No. 5,717,313 issued on Feb. 10, 1998, which is a continuation of U.S. Patent Application having U.S. Ser. No. 08/304,989 filed Sep. 13, 1994 and resulting in U.S. Pat. No. 5,548,201 issued on Aug. 20, 1996.
US Referenced Citations (7)
Continuations (2)
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Number |
Date |
Country |
Parent |
700205 |
Aug 1996 |
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Parent |
304989 |
Sep 1994 |
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