# US 12,763,586 B2 · Power supply device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,763,586 B2 - Document ID: US12763586B2 - Status: Granted - Kind: B2 - Application number: 18/268,507 - Filed: 2021-09-27 - Published: 2024-02-15 - Granted: 2026-10-13 - Earliest claimed: 2020-12-21 - Assignees: Fdk Corporation - Applicants: Fdk Corporation - Inventors: Kiyotaka Kumamoto; Yosuke Saito; Yasuyuki Katsube; Kazuhiro Hiwatashi - Web page: https://patentgrep.com/patent/US12763586B2 ## CPC - H02J 7/34: Parallel operation in networks using both storage and other DC sources, e.g. providing buffering (H02J7/14 takes precedence) - H02J 7/243: {with on/off action} - H02J 7/54: Passive balancing, e.g. using resistors or parallel MOSFETs - H02J 7/56: Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters - H02J 7/585: {Sequential battery discharge in systems with a plurality of batteries} - H02J 7/61: against overcharge - H02J 7/63: against overdischarge - H02J 7/82: Control of state of charge [SOC] - H02J 7/855: {with circuits adapted for supplying loads from the battery} - H02J 7/96: in response to battery voltage - H02J 9/06: with automatic change-over {, e.g. UPS systems} - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY ## Abstract This power supply device includes a battery unit which includes: a first battery pack; a step-up/down circuit for boosting the voltage of an external power supply up to the charge voltage of the battery pack; a first charge circuit; a first discharge circuit for detecting a voltage drop of the external power supply and performing discharge from the battery pack to a load device; and a control circuit for controlling charging and discharging. The discharge circuit has a first discharge switch and a second discharge switch which are connected in series between the battery pack and a power supply line. The first discharge switch is switched on/off by receiving a switching signal from the control circuit, and the second discharge switch is directly switched on/off not via the control circuit on the basis of the voltage of the external power supply. ## Claims ### Claim 1 A power supply device, comprising: a power supply line for supplying power from an external power supply to a load device; and a battery unit connected to the power supply line and connected in parallel with the external power supply, wherein the battery unit includes: a battery pack including a first battery pack and a second battery pack of which each charge voltage is higher than a voltage of the external power supply and which are connected to the power supply line in parallel with each other; a step-up/down circuit for stepping up the voltage of the external power supply to the charge voltage; a first charge circuit for charging the first battery pack at the charge voltage; a second charge circuit for charging the second battery pack at the charge voltage; a first discharge circuit for detecting a voltage drop of the external power supply and discharging from the first battery pack to the load device through the power supply line; and a second discharge circuit for detecting a voltage drop of the external power supply and discharging from the second battery pack to the load device through the power supply line; and a control circuit that controls the first charge circuit, the first discharge circuit, the second charge circuit and the second discharge circuit, wherein the first discharge circuit includes a first discharge switch and a second discharge switch connected in series between the first battery pack and the power supply line, the first discharge switch is switched to on/off by receiving a switching signal from the control circuit, and the second discharge switch is directly switched to on/off based on the voltage of the external power supply without via the control circuit, the first discharge circuit includes a third discharge switch and a fourth discharge switch connected in series between the second battery pack and the power supply line, the third discharge switch is switched to on/off by receiving a switching signal from the control circuit, and the fourth discharge switch is directly switched to on/off based on the voltage of the external power supply without via the control circuit, the first discharge circuit and the second discharge circuit are connected to the power supply line in parallel with each other and include a first voltage drop circuit and a second voltage drop circuit, respectively, for dropping the output voltage of the first battery pack and the second battery pack by a predetermined voltage to output the voltage to the power supply line, the first voltage drop circuit is connected between the power supply line and the second discharge switch, and the second voltage drop circuit is connected between the power supply line and the fourth discharge switch. ### Claim 2 (depends on 1) The power supply device according to claim 1, wherein the second discharge switch and the fourth discharge switch are turned on when the voltage of the external power supply decreases to a predetermined voltage or less. ### Claim 3 (depends on 1) The power supply device according to claim 1, wherein the control circuit monitors an output voltage of the first battery pack or the second battery pack, puts the battery unit in a dischargeable state by turning on the first discharge switch or the third discharge switch when the output voltage of the first battery pack or the second battery pack is within a dischargeable range, and puts the battery unit in a discharge prohibited state by turning off the first discharge switch or the third discharge switch when the output voltage is outside the dischargeable range. ### Claim 4 (depends on 3) The power supply device according to claim 3, wherein a lower limit of the dischargeable range of the output voltage of the first battery pack and the second battery pack is determined to a final discharge voltage of the first battery pack and the second battery pack, and an upper limit of the dischargeable range is determined to an upper limit of an allowable voltage of the load device. ### Claim 5 (depends on 4) The power supply device according to claim 4, wherein an output voltage of the first battery pack and the second battery pack in a fully charged state is higher than the upper limit of the allowable voltage of the load device. ### Claim 6 (depends on 3) The power supply device according to claim 3, wherein the control circuit charges the first battery pack or the second battery pack to a fully charged state, and maintains the discharge prohibited state of the battery unit by putting the first discharge switch or the third discharge switch in an off state until the output voltage of the first battery pack or the second battery pack decreases to within the dischargeable range after the first battery pack or the second battery pack reaches the fully charged state. ### Claim 7 (depends on 3) The power supply device according to claim 3, wherein each of the first voltage drop circuit and the second voltage drop circuit is formed of a diode or a transistor. ### Claim 8 (depends on 3) The power supply device according to claim 3, wherein each of the first voltage drop circuit and the second voltage drop circuit is formed of a resistive element. ### Claim 9 (depends on 3) The power supply device according to claim 3, wherein an upper limit of the dischargeable range rises by the predetermined voltage dropped by the first voltage drop circuit or the second voltage drop circuit. ### Claim 10 (depends on 1) The power supply device according to claim 1, wherein each of the first discharge switch the second discharge switch, the third discharge switch and the fourth discharge switch is formed of an insulated gate field effect transistor, a gate electrode of the first discharge switch and the third discharge switch is driven by the switching signal from the control circuit, and a gate electrode of the second discharge switch and the fourth discharge switch is driven by a driving circuit that instantaneously responds to the voltage drop of the external power supply. ### Claim 11 (depends on 1) The power supply device according to claim 1, wherein at least one of the first battery pack and/or the second battery pack is in a dischargeable state.