To provide a battery charger and a battery charging method that shorten time to equalize the voltage of cells and safely perform cell balancing processing.
A battery charger comprises a pulse width modulation unit which changes target voltages of first and second cells from internal resistance of the first and second cells and an average of starting voltages of the first and second cells, performs pulse width modulation processing to perform constant current charging until the changed target voltages of the first and second cells are reached, stops the pulse width modulation processing to perform constant current charging when the voltages of the first and second cells become the changed target voltages of the first and second cells after the voltages of the first and second cells are equalized, moves to pulse width modulation processing to perform constant voltage charging when a threshold value of over-discharging or a threshold value of over-charging is reached, and stops the pulse width modulation processing to perform constant voltage charging when current flowing through the first and second cells reach a target current of over-discharging or a target current of over-charging so that the threshold value of over-discharging or the threshold value of over-charging will be not exceeded.
| JP2021164333 | VEHICLE POWER SOURCE DEVICE |
| WO/2019/170185 | BATTERY STORAGE SYSTEM |
| WO/2019/235027 | BATTERY PACK MONITORING SYSTEM |
HIROSE SHINJI
SUZUKI MASAAKI
MAKISHI WATARU
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