# US 12,181,535 B2 · Method and device for estimating the usable charge capacity of an electrical energy store > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,535 B2 - Document ID: US12181535B2 - Status: Granted - Kind: B2 - Application number: 17/784,837 - Filed: 2020-11-25 - Published: 2023-01-12 - Granted: 2024-12-31 - Earliest claimed: 2019-12-16 - Assignees: Bayerische Motoren Werke Aktiengesellschaft - Applicants: Bayerische Motoren Werke Aktiengesellschaft - Inventors: Bastian Buchholz; Andreas Ertlmeier; Julian Wiesmeier - Web page: https://patentgrep.com/patent/US12181535B2 ## CPC - G01R 31/392: Determining battery ageing or deterioration, e.g. state of health - B60L 58/12: responding to state of charge [SoC] - B60L 58/16: responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH] - G01R 31/367: Software therefor, e.g. for battery testing using modelling or look-up tables - G01R 31/396: Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery - B60L 2260/44: by parameter estimation - G01R 31/006: {on road vehicles, e.g. automobiles or trucks (testing of ignition installations peculiar to internal combustion engines F02P17/00)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - 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 A method for estimating the usable charge capacity of an electrical energy store includes determining a nominal initial charge capacity and a maximum initial estimation error of a new or slightly degraded energy store; determining one or more nominal charge capacities and one or more maximum estimation errors for the degraded energy store; interpolating a graph for the nominal charge capacity and for the maximum lower and upper estimation errors between the interpolation points of the nominal charge capacity and the interpolation points of the maximum estimation errors; and estimating a nominal charge state, a current usable charge capacity with a lower estimation reserve, and a current usable charge capacity with an upper estimation reserve for a current degradation state of the electrical energy store. ## Claims ### Claim 1 A method for estimating a usable charge capacity of an electrical energy store, the method comprising: determining a nominal initial charge capacity and a maximum initial estimation error of a new energy store or a degraded energy store; determining one or more nominal charge capacities and one or more maximum estimation errors for the degraded energy store; interpolating a characteristic of a nominal charge capacity and of maximum lower and upper estimation errors between interpolation points of the nominal initial charge capacity and the one or more nominal charge capacities, and interpolation points of the maximum initial estimation error and the one or more maximum estimation errors; and estimating a nominal state-of-charge, a current usable charge capacity with a lower estimation reserve, and a current usable charge capacity with an upper estimation reserve for a current degradation state of the electrical energy store. ### Claim 2 (depends on 1) The method according to claim 1, wherein interpolation for two of the interpolation points is executed in a linear manner and, for more than two of the interpolation points, in a sectionally linear manner. ### Claim 3 (depends on 1) The method according to claim 1, wherein interpolation for two of the interpolation points is executed in a linear manner and, for more than two of the interpolation points, by way of a regression curve defined by a least squares method. ### Claim 4 (depends on 1) The method according to claim 1, wherein interpolation for two of the interpolation points is executed by way of a typical model curve for the electrical energy store and, for more than two of the interpolation points, by way of a connecting curve or a regression curve, which connects the interpolation points or which minimizes a sum of deviation squares of the interpolation points. ### Claim 5 (depends on 1) The method according to claim 1, wherein interpolation of the usable charge capacity and the one or more maximum estimation errors is executed by way of a knowledge-based system or a neural network, which is trainable by way of known degradation states, known charge capacities and thus associated estimation errors of the electrical energy store. ### Claim 6 (depends on 1) The method according to claim 1, wherein individual interpolation points or an overall characteristic of the nominal charge capacity and the maximum lower and upper estimation errors for the electrical energy store are plotted and/or preset, and/or are adjusted and/or expanded in a course of degradation. ### Claim 7 (depends on 1) A device comprising: a processer configured to execute the method according to claim 1; circuits configured to monitor energy storage cells; a battery management system; and an indicator system configured to indicate the current usable charge capacity, the current degradation state, and/or a residual service life of the electrical energy store. ### Claim 8 (depends on 7) A vehicle comprising the device according to claim 7.