Cell equalizing circuit
US7061207B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 2002 |
| Grant date | Jun 13, 2006 |
| Priority date | — |
| Expiry date | May 24, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J7/0018
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electric circuit for equalizing voltages between serially arranged cells. The circuit is operable to generate AC voltages at amplitudes dependent on the DC voltages of the received cells. The AC voltages are all connected to an inductive coupling circuit. The inductive coupling allows higher-voltage cells to induce a recharging current flow in lower voltage cells and so equalize the cell voltages. The circuit also operates to ensure that cell voltages are maintained in equilibrium during charging or discharging of received cells, irrespective of the individual charging and discharging characteristics of the cells. The circuit thus prevents individual cells in a battery from being over-charged or over-discharged and allows more efficient use of the full capacity of a battery without risking damage to the individual cells. The cell equalizing circuit is thus especially useful for rechargeable cells, such as lithium-ion cells, which are sensitive to damage by over-charging and over-discharging.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.