CHARGING DEVICE

• US 20120001595A1
• Filed: 03/31/2009
• Published: 01/05/2012
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: Iwasaki Electric Company Limited, JPS Co., Ltd. (P-POP KK), Tokyo Rectifier Co., Ltd.
• Original Assignee: Iwasaki Electric Company Limited, JPS Co., Ltd. (P-POP KK), Tokyo Rectifier Co., Ltd.
• Inventors: Maruyama, Tomomi, Saiki, Eiji, Kato, Akitoshi, Honda, Yoshihiro
• Granted Patent: US 8,975,870 B2
• Time in Patent Office: Days
• US Class Current: 320/118
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

A charging device supplies charge current to a battery group having plural secondary batteries connected in series to perform charging. In the charging device, a discharge route circuit for discharging charge current to be supplied to the secondary battery when the battery voltage of the secondary battery exceeds a predetermined voltage while charging is provided to every secondary battery. Also provided is a cut-off circuit for cutting off the discharge route circuit from each secondary battery after charging is completed. Discharge at a discharge route circuit is suppressed and energy efficiency is increased.

Claims

1. A charging device for supplying charge current to a battery group having a plurality of secondary batteries which are connected to one another in series, characterized by comprising:

a discharge route circuit that is provided every secondary battery and discharges the charge current to be supplied to the secondary battery when a battery voltage of the secondary battery exceeds a predetermined voltage during charging; and

a cut-off unit for cutting off the discharge route circuit from each secondary battery after the charging is completed.

2. The charging device according to claim 1, further comprising a charge control unit that reduces the charge current when any secondary battery starts discharge to the discharge route circuit thereof, and continues charging until the discharge from the secondary battery to the discharge route circuit is stopped.

4. The charging device according claim 1, further comprising a charger for supplying external power to a parallel circuit in which the battery group and an external load are connected to each other in parallel, thereby charging the battery group and supplying power to the external load, wherein under non-charging a voltage applied to the parallel circuit by the charger is controlled so that charge current flowing into the battery group is kept to be substantially zero while the battery group and the external load are kept under a conduction state.

5. The charging device according claim 2, further comprising a charger for supplying external power to a parallel circuit in which the battery group and an external load are connected to each other in parallel, thereby charging the battery group and supplying power to the external load, wherein under non-charging a voltage applied to the parallel circuit by the charger is controlled so that charge current flowing into the battery group is kept to be substantially zero while the battery group and the external load are kept under a conduction state.

3. A charging device for supplying charge current to a battery group having a plurality of secondary batteries which are connected to one another in series, characterized by comprising:

a voltage detecting resistor for detecting a battery voltage of each secondary battery;

a discharge route circuit that is provided every secondary battery and discharges the charge current to be supplied to the secondary battery when a battery voltage of the secondary battery exceeds a predetermined voltage during charging; and

a cut-off unit for cutting off the discharge route circuit from each secondary battery after the charging is completed, wherein the voltage detecting resistor has a plurality of resistance elements that are connected to one another in series, and short-circuit units each of which individually short-circuits each of the resistance elements.

6. The charging device according claim 3, further comprising a charger for supplying external power to a parallel circuit in which the battery group and an external load are connected to each other in parallel, thereby charging the battery group and supplying power to the external load, wherein under non-charging a voltage applied to the parallel circuit by the charger is controlled so that charge current flowing into the battery group is kept to be substantially zero while the battery group and the external load are kept under a conduction state.