# US 12,000,896 B2 · Battery system, SOC estimation method for battery system, computer apparatus, and medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,000,896 B2 - Document ID: US12000896B2 - Status: Granted - Kind: B2 - Application number: 18/131,433 - Filed: 2023-04-06 - Published: 2023-08-03 - Granted: 2024-06-04 - Earliest claimed: 2021-01-08 - Assignees: Nio Technology (Anhui) Co., Ltd - Applicants: Nio Technology (Anhui) Co., Ltd - Inventors: Wei Cai; Rui Hua; Shizhe Tzeng; Haoming Yan - Web page: https://patentgrep.com/patent/US12000896B2 ## CPC - G01R 31/367: Software therefor, e.g. for battery testing using modelling or look-up tables - G01R 31/382: Arrangements for monitoring battery or accumulator variables, e.g. SoC - G01R 31/396: Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery - G07C 5/12: in graphical form - H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines} - H01M 10/052: Li-accumulators - H01M 10/4207: {for several batteries or cells simultaneously or sequentially} - H01M 10/425: {Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00)} - H01M 10/48: Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) - H02J 7/82: Control of state of charge [SOC] - B60L 58/21: having the same nominal voltage - H01M 2010/4271: {Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES ## Abstract An SOC estimation method for a battery system includes mapping an upper limit and a lower limit of the state of charge of the second-system battery to a state of charge interval of the battery system, to establish a mapping relationship between the upper limit and the lower limit of the state of charge of the second-system battery and the state of charge interval of the battery system. The method includes calculating the state of charge of the second-system battery and estimating a state of charge of the battery system according to the mapping relationship. ## Claims ### Claim 1 A state of charge (SOC) estimation method for a battery system, wherein the battery system comprises a first-system battery and a second-system battery, and the method comprises: mapping, by a processor, an upper limit and a lower limit of a state of charge of the second-system battery to a state of charge interval of the battery system, to establish a mapping relationship between the upper limit and the lower limit of the state of charge of the second-system battery and the state of charge interval of the battery system; determining an open-circuit voltage of the second-system battery; and calculating, by the processor, the state of charge of the second-system battery based on the open-circuit voltage of the second-system battery and estimating, using the calculated state of charge of the second-system battery, a state of charge of the battery system according to the mapping relationship, the estimated state of charge of the battery system being a value that reflects the state of charge of the second-system battery and a state of charge of the first-system battery, wherein a slope of an open circuit voltage-state of charge (OCV-SOC) curve of the second-system battery is larger than a slope of an OCV-SOC curve of the first-system battery. ### Claim 2 (depends on 1) The method according to claim 1, wherein: the lower limit of the state of charge of the second-system battery is kept at an empty point of 0% of the battery system, and a corresponding state of charge of the first-system battery is a level SOC_L; while an upper limit of the first-system battery is kept at a full point of 100% of the battery system, and a corresponding state of charge of the second-system battery is a level SOC_H; a state of charge interval of the second-system battery is kept from the empty point of 0% of the battery system to the level SOC_H; and two state of charge intervals, 0 to the level SOC_L and the level SOC_H to 100%, are reserved and are used to dynamically adjust the state of charge interval of the second-system battery in the case that the battery system is degraded. ### Claim 3 (depends on 1) The method according to claim 1, further comprising: dynamically adjusting a state of charge interval of the first-system battery and a state of charge interval of the second-system battery such that the state of charge of the second-system battery always accurately reflects the state of charge of the battery system. ### Claim 4 (depends on 3) The method according to claim 3, wherein said dynamically adjusting further comprises: setting a lower limit of the state of charge of the first-system battery to be lower than the lower limit of the state of charge of the second-system battery, and setting the upper limit of the state of charge of the second-system battery to be higher than an upper limit of the state of charge of the first-system battery. ### Claim 5 (depends on 4) The method according to claim 4, wherein said dynamically adjusting further comprises: opening the lower limit of the state of charge of the first-system battery and adding the opened lower limit to the state of charge interval of the second-system battery. ### Claim 6 (depends on 5) The method according to claim 5, wherein said dynamically adjusting further comprises: in the case that the first-system battery is degraded more than the second-system battery, opening downwards the state of charge interval of the first-system battery, and adding the opened state of charge interval of the first-system battery to the state of charge interval of the second-system battery, so that an available state of charge interval of the second-system battery remains the same as before the addition. ### Claim 7 (depends on 5) The method according to claim 5, wherein said dynamically adjusting further comprises: lowering the upper limit of the state of charge of the second-system battery and adding the lowered upper limit to the state of charge interval of the first-system battery. ### Claim 8 (depends on 5) The method according to claim 5, wherein said dynamically adjusting further comprises: in the case that the first-system battery is continuously degraded and the first-system battery is degraded more than that of the second-system battery by a threshold, lowering the upper limit of the state of charge of the second-system battery and adding the lowered upper limit to the state of charge interval of the first-system battery. ### Claim 9 (depends on 4) The method according to claim 4, wherein said dynamically adjusting further comprises: opening the upper limit of the state of charge of the second-system battery and adding the opened upper limit to the state of charge interval of the second-system battery. ### Claim 10 (depends on 9) The method according to claim 9, wherein said dynamically adjusting further comprises: in the case that the second-system battery is degraded more than the first-system battery, gradually opening upwards the upper limit of the state of charge of the second-system battery so that the opened upper limit of the state of charge of the second-system battery is aligned with a full point of the first-system battery. ### Claim 11 (depends on 1) The method according to claim 1, wherein the first-system battery is a lithium iron phosphate-system battery, and the second-system battery is a nickel cobalt manganese-system battery. ### Claim 12 A battery system, comprising: a first-system battery; a second-system battery; a processor; and a memory including instructions that when executed by the processor cause the processor to: map an upper limit and a lower limit of a state of charge of the second-system battery to a state of charge interval of the battery system, to establish a mapping relationship between the upper limit and the lower limit of the state of charge of the second-system battery and the state of charge interval of the battery system; determine an open-circuit voltage of the second-system battery; and calculate the state of charge of the second-system battery based on the open-circuit voltage of the second-system battery and estimate, using the calculated state of charge of the second-system battery, a state of charge of the battery system according to the mapping relationship, the estimated state of charge of the battery system being a value that reflects the state of charge of the second-system battery and a state of charge of the first-system battery, wherein a slope of an open circuit voltage-state of charge (OCV-SOC) curve of the second-system battery is larger than a slope of an OCV-SOC curve of the first-system battery. ### Claim 13 (depends on 12) The battery system according to claim 12, wherein: the lower limit of the state of charge of the second-system battery is kept at an empty point of 0% of the battery system, and a corresponding state of charge of the first-system battery is a level SOC_L; while an upper limit of the first-system battery is kept at a full point of 100% of the battery system, and a corresponding state of charge of the second-system battery is a level SOC_H; a state of charge interval of the second-system battery is kept from the empty point of 0% of the battery system to the level SOC_H; and two state of charge intervals, 0 to the level SOC_L and the level SOC_H to 100%, are reserved and are used to dynamically adjust the state of charge interval of the second-system battery in the case that the battery system is degraded. ### Claim 14 (depends on 12) The battery system according to claim 12, wherein the memory includes instructions that when executed by the processor cause the processor to dynamically adjust a state of charge interval of the first-system battery and a state of charge interval of the second-system battery such that the state of charge of the second-system battery always accurately reflects the state of charge of the battery system. ### Claim 15 (depends on 14) The battery system according to claim 14, wherein said dynamically adjusting further comprises: setting a lower limit of the state of charge of the first-system battery to be lower than the lower limit of the state of charge of the second-system battery, and setting the upper limit of the state of charge of the second-system battery to be higher than an upper limit of the state of charge of the first-system battery. ### Claim 16 (depends on 15) The battery system according to claim 15, wherein said dynamically adjusting further comprises: opening the lower limit of the state of charge of the first-system battery and adding the opened lower limit to the state of charge interval of the second-system battery. ### Claim 17 (depends on 16) The battery system according to claim 16, wherein said dynamically adjusting further comprises: in the case that the first-system battery is degraded more than the second-system battery, opening downwards the state of charge interval of the first-system battery, and adding the opened state of charge interval of the first-system battery to the state of charge interval of the second-system battery so that an available state of charge interval of the second-system battery remains the same as before the addition. ### Claim 18 (depends on 16) The battery system according to claim 16, wherein said dynamically adjusting further comprises: lowering the upper limit of the state of charge of the second-system battery and adding the lowered upper limit to the state of charge interval of the first-system battery. ### Claim 19 (depends on 16) The battery system according to claim 16, wherein said dynamically adjusting further comprises: in the case that the first-system battery is continuously degraded and the first-system battery is degraded more than that of the second-system battery by a threshold, lowering the upper limit of the state of charge of the second-system battery and adding the lowered upper limit to the state of charge interval of the first-system battery. ### Claim 20 (depends on 15) The battery system according to claim 15, wherein said dynamically adjusting further comprises: opening the upper limit of the state of charge of the second-system battery and adding the opened upper limit to the state of charge interval of the second-system battery. ### Claim 21 (depends on 20) The battery system according to claim 20, wherein said dynamically adjusting further comprises: in the case that the first-system battery is degraded more than the second-system battery, opening downwards the state of charge interval of the first-system battery, and adding the opened state of charge interval of the first-system battery to the state of charge interval of the second-system battery so that an available state of charge interval of the second-system battery remains the same as before the addition. ### Claim 22 (depends on 12) The battery system according to claim 12, wherein the first-system battery is a lithium iron phosphate-system battery, and the second-system battery is a nickel cobalt manganese-system battery. ### Claim 23 A computer device for estimating a state of charge of a battery system that comprises a first-system battery and a second-system battery, the computer device comprising: a memory; a processor; and a computer program stored on the memory and executable on the processor, wherein when the computer program is executed by the processor, the processor: maps an upper limit and a lower limit of a state of charge of the second-system battery to a state of charge interval of the battery system, to establish a mapping relationship between the upper limit and the lower limit of the state of charge of the second-system battery and the state of charge interval of the battery system; determines an open-circuit voltage of the second-system battery; and calculates the state of charge of the second-system battery based on the open-circuit voltage of the second-system battery and estimates, using the calculated state of charge of the second-system battery, the state of charge of the battery system according to the mapping relationship, the estimated state of charge of the battery system being a value that reflects the state of charge of the second-system battery and a state of charge of the first-system battery, wherein a slope of an open circuit voltage-state of charge (OCV-SOC) curve of the second-system battery is larger than a slope of an OCV-SOC curve of the first-system battery.