Method for detecting fully-charged state of rechargeable battery
US6064181A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1998 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Mar 6, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/16542
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The difference voltage between the terminal voltage VB of a rechargeable battery BAT and a reference voltage Vz1 is amplified at an initial gain, thereby reducing an amplified voltage value S12. This amplified voltage value S12 is A/D converted into digital value S13. Further, an electrical signal S18 is detected corresponding to the ambient temperature around the battery and is then A/D converted into a digital value S19. Digital values S13 and S19 charge with the progress of charging of the rechargeable battery. The change in these digital values is read by CPU 14 one after another, and the gain used in amplification of the difference voltage is renewed by the gains corresponding to digital values S13 and S19, which are stored in advance in a ROM 20. In the same manner, the reference voltage used in amplification of the difference voltage is renewed by reference voltages Vz2, Vz3, and Vz4 one by one with the progress of charging of the rechargeable battery. When the digital value S13 is decreased, CPU 14 judges that charging of the rechargeable battery is completed, thus a voltage drop -.DELTA.V being caused in the terminal voltage VB, and controls a constant current circuit port…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.