Charger for lithium ion secondary battery, and method of charging the same
US8098053B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 2007 |
| Grant date | Jan 17, 2012 |
| Priority date | — |
| Expiry date | Aug 13, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J2207/20
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A charger for a lithium ion secondary battery includes a series circuit of a reverse-current preventive switch, a charging switch and a current-detecting resistor, connected between the battery and the ground a charging control circuit controlling the reverse-current preventive switch and the charging switch, so as to make the battery repeat charging and opening at regular intervals, and so as to detect voltage difference between the specified voltage and the open circuit voltage of the battery during the opening; and a constant-current/constant-voltage control circuit commanding constant-current charging at a first set voltage set relatively high in a range not exceeding the upper limit voltage of the battery, so far as the voltage difference does not exceed a predetermined change-over voltage difference, and commanding constant-voltage charging at a second set voltage, which is lowered from the first set voltage, when the voltage difference becomes smaller than the change-over voltage difference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.