# US 2024/0201261 A1 · Device and method for diagnosing damage to switch in battery protection circuit, and battery management device comprising same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0201261 A1 - Document ID: US20240201261A1 - Status: Published application - Kind: A1 - Application number: 18/287,259 - Filed: 2022-09-15 - Published: 2024-06-20 - Earliest claimed: 2021-12-22 - Assignees: LG Energy Solution, Ltd. - Applicants: LG Energy Solution, Ltd. - Inventors: Seung Min YANG; Yun JANG - Web page: https://patentgrep.com/patent/US20240201261A1 ## CPC - G01R 31/3277: {of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches} - G01R 31/3333: {Apparatus, systems or circuits therefor} - G01R 19/16566: {Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533} - G01R 31/3835: involving only voltage measurements - H02J 7/00: Circuit arrangements for charging or discharging batteries or for supplying loads from batteries - H02J 7/61: against overcharge - H02J 7/63: against overdischarge - H02J 7/663: {using battery or load disconnect circuits (H02J9/002 takes precedence)} - G01R 31/2621: {for testing field effect transistors, i.e. FET's} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY ## Abstract An apparatus and method for diagnosing damage of a switch in a battery protection circuit include a battery protection circuit including a first switch and a second switch connected to a battery pack and a switch damage diagnosing device for measuring in the battery protection circuit and for diagnosing whether any one of the first switch and the second switch is damaged. The source terminal of the first switch and the source terminal of the second switch can be connected to a common source, which can diagnose whether or not the switch is damaged only by measuring the voltage at a certain point without measuring a current. ## Claims ### Claim 1 A battery management apparatus comprising: a battery protection circuit including a first switch and a second switch connected to a battery pack; and a switch damage diagnosing device configured to measure a voltage at one or more points in the battery protection circuit and to diagnose whether any one of the first switch and the second switch is damaged, wherein the source terminal of the first switch and the source terminal of the second switch are connected to a common source. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the first switch is a discharge control transistor configured to control a discharge circuit when discharging the battery pack, and wherein the second switch is a charge control transistor configured to control a charge circuit when charging the battery pack. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein a drain terminal of the first switch in the battery protection circuit is connected to a positive electrode of the battery pack and a drain terminal of the second switch in the battery protection circuit is connected to a load. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the battery protection circuit further includes a voltage applying circuit, wherein a first end of the voltage applying circuit is connected to a first point between the battery pack and the drain terminal of the first switch, and a second end of the voltage applying circuit is connected to a second point between the drain terminal of the second switch and the load, and wherein the voltage applying circuit is configured to bypass the first switch and the second switch to apply a voltage of the battery pack to the second point. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the voltage applying circuit comprises a P-channel switching circuit. ### Claim 6 (depends on 3) The apparatus of claim 3, wherein the one or more points in the battery protection circuit include: a first point between the battery pack and the drain terminal of the first switch; a second point between the drain terminal of the second switch and the load; and a third point at which a source terminal of the first switch and a source terminal of the second switch are connected to a common source. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the switch damage diagnosing device is configured to determine that the first switch and the second switch are normally operating, when a voltage at the third point is less than or equal to a threshold value. ### Claim 8 (depends on 6) The apparatus of claim 6, wherein the switch damage diagnosing device is configured to determine that the first switch and the second switch are normally operating, when a voltage at the first point and a voltage at the second point are greater than or equal to a threshold value and the voltage at the third point is less than or equal to the threshold value. ### Claim 9 (depends on 6) The apparatus of claim 6, wherein the switch damage diagnosing device is configured to determine that any one of the first switch and the second switch is damaged, when voltages at the first point, the second point and the third point are greater than or equal to the threshold value. ### Claim 10 A method for diagnosing damage of a switch in a battery protection circuit including a first switch and a second switch connected to a battery pack, the method comprising: measuring a voltage at one or more points in the battery protection circuit; and comparing the voltage with a threshold value to diagnose whether any one of the first switch and the second switch is damaged, wherein a source terminal of the first switch and a source terminal of the second switch are connected to a common source. ### Claim 11 (depends on 10) The method of claim 10, wherein the first switch is a discharge control transistor configured to control a discharge circuit when discharging the battery pack, and wherein the second switch is a charge control transistor configured to control a charge circuit when charging the battery pack. ### Claim 12 (depends on 10) The method of claim 10, wherein the battery protection circuit further includes a voltage applying circuit, wherein a first end of the voltage applying circuit is connected to a first point between the battery pack and a drain terminal of the first switch, and a second end of the voltage applying circuit is connected to a second point between a drain terminal of the second switch and a load, and wherein the voltage applying circuit bypasses the first switch and the second switch to apply a voltage of the battery pack to the second point. ### Claim 13 (depends on 12) The method of claim 12, wherein the voltage applying circuit comprises a P-channel switching circuit. ### Claim 14 (depends on 12) The method of claim 12, wherein the measuring the voltage at the one or more points in the battery protection circuit includes: measuring a voltage at a first point between the battery pack and the drain terminal of the first switch; measuring a voltage at a second point between the drain terminal of the second switch and the load; and measuring a voltage at a third point at which the source terminal of the first switch and the source terminal of the second switch are connected to the common source. ### Claim 15 (depends on 14) The method of claim 14, wherein the comparing the voltage with the threshold value to diagnose whether any one of the first switch and the second switch is damaged includes determining that the first switch and the second switch are normally operating when the voltage at the third point is less than or equal to the threshold value. ### Claim 16 (depends on 14) The method of claim 14, wherein the comparing the voltage with the threshold to diagnose whether any one of the first switch and the second switch is damaged includes determining that the first switch and the second switch are normally operating when the voltage at the first point and the voltage at the second point are greater than or equal to the threshold value and the voltage at the third point is less than or equal to the threshold value. ### Claim 17 (depends on 14) The method of claim 14, wherein the comparing the voltage with the threshold to diagnose whether any one of the first switch and the second switch is damaged includes determining that any one of the first switch and the second switch is damaged, when the voltages at the first point, the second point and the third point are greater than or equal to the threshold value. ### Claim 18 (depends on 12) The method of claim 12, wherein the first switch and the second switch are high side type power transistors positioned closer to the battery pack relative to the load. ### Claim 19 An apparatus for diagnosing damage of a switch in a battery protection circuit including a first switch and a second switch connected to a battery pack, the apparatus comprising: at least one processor; and a memory configured to store at least one instruction executed by the at least one processor, wherein the at least one instruction includes: an instruction to measure a voltage at one or more points in the battery protection circuit; and an instruction to compare the voltage with a threshold value to diagnose whether any one of the first switch and the second switch is damaged, and wherein a source terminal of the first switch and a source terminal of the second switch are connected to a common source. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the first switch is a discharge control transistor configured to control a discharge circuit when discharging the battery pack, and wherein the second switch is a charge control transistor configured to control a charge circuit when charging the battery pack. ### Claim 21 (depends on 19) The apparatus of claim 19, wherein the battery protection circuit further includes a voltage applying circuit, wherein a first end of the voltage applying circuit is connected to a first point between the battery pack and a drain terminal of the first switch, and a second end of the voltage applying circuit is connected to a second point between a drain terminal of the second switch and a load, and wherein the voltage applying circuit is configured to bypass the first switch and the second switch to apply a voltage of the battery pack to the second point. ### Claim 22 (depends on 21) The apparatus of claim 21, wherein the voltage applying circuit comprises a P-channel switching circuit. ### Claim 23 (depends on 21) The apparatus of claim 21, wherein the instruction to measure the voltage at the one or more points in the battery protection circuit includes: an instruction to measure a voltage at a first point between the battery pack and the drain terminal of the first switch; an instruction to measure a voltage at a second point between the drain terminal of the second switch and the load; and an instruction to measure a voltage at a third point which the source terminal of the first switch and the source terminal of the second switch are connected to the common source. ### Claim 24 (depends on 23) The apparatus of claim 23, wherein the instruction to compare the voltage with the threshold value to diagnose whether any one of the first switch and the second switch is damaged includes an instruction to determine that the first switch and the second switch are normally operating, when the voltage at the first point and the voltage at the second point are greater than or equal to the threshold value and the voltage at the third point is less than or equal to the threshold value. ### Claim 25 (depends on 23) The apparatus of claim 23, wherein the instruction to compare the voltage with the threshold value to diagnose whether any one of the first switch and the second switch is damaged includes an instruction to determine that the first switch and the second switch are normally operating, when the voltage at the third point is less than or equal to the threshold value. ### Claim 26 (depends on 23) The apparatus of claim 23, wherein the instruction to compare the voltage with the threshold value to diagnose whether any one of the first switch and the second switch is damaged includes an instruction to determine that any one of the first switch and the second switch is damaged, when the voltages at the first point, the second point and third point are greater than or equal to the threshold value. ### Claim 27 (depends on 21) The apparatus of claim 21, wherein the first switch and the second switch are high side type power transistors positioned closer to the battery pack relative to the load.