BATTERY PACK AND BATTERY PACK SYSTEM

• US 20110254508A1
• Filed: 04/11/2011
• Published: 10/20/2011
• Est. Priority Date: 04/14/2010
• Status: Active Grant

• Current Assignee: Kazuyuki Sakakibara
• Original Assignee: Kazuyuki Sakakibara
• Inventors: Sakakibara, Kazuyuki
• Granted Patent: US 8,638,065 B2
• Time in Patent Office: Days
• US Class Current: 320/118
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack usable as a power source of an electric device, is disclosed, in which battery modules are in series; each battery module is configured to include battery cells in series; a discharge controller controls discharge power which is supplied from the battery modules to the electric device; a modulator modulates a voltage of each module between a high voltage and a low voltage which is higher than zero and lower than the high voltage; the high voltage and the low voltage are set to allow a load device of the electric device to operate by the high voltage, and to allow the load device not to operate by the low voltage; and the discharge controller operates by the battery modules, irrespective of whether each module outputs the high voltage or the low voltage.

Claims

1. A battery pack usable as a power source of an electric device, comprising:

a battery module group in which a plurality of battery modules are interconnected in series; and

a discharge output terminal through which discharge power is supplied from the battery module group to the electric device,

wherein each battery module is configured to include a battery cell group in which a plurality of battery cells are interconnected in series,

the battery pack further comprising;

a discharge controller configured to control the discharge power which is supplied from the battery module group to the electric device; and

an output voltage modulator configured to modulate a module output voltage of each battery module between a high voltage and a low voltage which is higher than zero and lower than the high voltage, depending on an instruction signal from the discharge controller,

wherein the electric device is configured to include a load device,

the load device operates by the discharge power of the battery module group when each battery module outputs the high voltage, and does not operate by the discharge power of the battery module group when each battery module outputs the low voltage, and

the discharge controller operates by the battery module group, irrespective of whether each battery module outputs the high voltage or the low voltage.

2. The battery pack according to claim 1, wherein the output voltage modulator is configured to include:

a switching device which is connected with a current path allowing a current to flow to the battery module group and the discharge output terminal, and which varies between an ON state and an OFF state, in response to a control signal; and

switching-control circuitry configured to perform switching control for the switching device, by supplying the control signal with a variable duty ratio, to the switching device, and to control the control signal such that the duty ratio varies between when the module output voltage is equal to the high voltage and when the module output voltage is equal to the low voltage.

3. The battery pack according to claim 1, wherein the output voltage modulator is configured to include:

a switching device which is connected with a current path allowing a current to flow to the battery module group and the discharge output terminal, and which varies between an ON state and an OFF state, in response to a control signal; and

a voltage divider connected to the battery cell group in parallel, per each battery module, and configured to selectively divide a total voltage of the battery cells that belong to the battery cell group, to produce a fractional voltage of the total voltage, such that, when the switching device is in the ON state, the module output voltage is equal to the total voltage, and when the switching device is in the OFF state, the module output voltage is equal to the fractional voltage.

4. The battery pack according to claim 1, wherein the output voltage modulator is configured to modulate the module output voltage substantially continuously or in steps, as time elapses, during a period in which the module output voltage transitions between the high voltage and the low voltage.

5. A battery pack system having an electric device and a battery pack usable as a power source of the electric device, comprising:

a battery module group in which a plurality of battery modules are interconnected in series; and

a discharge output terminal through which discharge power is supplied from the battery module group to the electric device,

wherein each battery module is configured to include a battery cell group in which a plurality of battery cells are interconnected in series,

the battery pack system further comprising;

a discharge controller configured to control the discharge power which is supplied from the battery module group to the electric device; and

an output voltage modulator configured to modulate a module output voltage of each battery module between a high voltage and a low voltage which is higher than zero and lower than the high voltage, depending on an instruction signal from the discharge controller, wherein

the high voltage and the low voltage are set to allow a load device of the electric device to operate by the discharge power of the battery module group when each battery module outputs the high voltage, and to allow the load device not to operate by the discharge power of the battery module group when each battery module outputs the low voltage, and

the discharge controller operates by the battery module group, irrespective of whether each battery module outputs the high voltage or the low voltage.