# US 2023/0408599 A1 · Method and apparatus for estimating aging of satellite battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0408599 A1 - Document ID: US20230408599A1 - Status: Published application - Kind: A1 - Application number: 18/328,917 - Filed: 2023-06-05 - Published: 2023-12-21 - Earliest claimed: 2022-06-16 - Assignees: Korea Aerospace Research Institute - Applicants: Korea Aerospace Research Institute - Inventors: Seok-Teak YUN - Web page: https://patentgrep.com/patent/US20230408599A1 ## CPC - G01R 31/392: Determining battery ageing or deterioration, e.g. state of health - G01R 31/367: Software therefor, e.g. for battery testing using modelling or look-up tables - G01R 31/3835: involving only voltage measurements - 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) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY ## Abstract A method for estimating an aging amount of a battery mounted on a satellite includes receiving battery voltage and current data generated by detecting a voltage and current of the battery in a preset first sensing period during a precise sensing period, determining a mission start time point based on the battery current data, obtaining a first battery voltage value of a first time point based on the battery voltage data and the mission start time point, obtaining a second battery voltage value of a second time point when a preset reference time elapses from the first time point based on the battery voltage data, and estimating the aging amount of the battery based on a sensing voltage difference between the first battery voltage value and the second battery voltage value, a first reference voltage difference, and a second reference voltage difference. ## Claims ### Claim 1 A method of estimating an aging amount of a battery mounted on a satellite that performs a satellite mission, the method comprising: receiving battery voltage and current data generated by detecting a voltage and current of the battery in a preset first sensing period during a precise sensing period; determining a mission start time point when the satellite begins to perform the satellite mission based on the battery current data; obtaining a first battery voltage value of a first time point immediately before the satellite performs the satellite mission based on the battery voltage data and the mission start time point; obtaining a second battery voltage value of a second time point when a preset reference time elapses from the first time point based on the battery voltage data; and estimating the aging amount of the battery of the satellite based on a sensing voltage difference between the first battery voltage value and the second battery voltage value, a first reference voltage difference, and a second reference voltage difference. ### Claim 2 (depends on 1) The method of claim 1, wherein the precise sensing period comprises a satellite mission execution period in which the satellite performs the satellite mission. ### Claim 3 (depends on 2) The method of claim 2, wherein the satellite performs the satellite mission by using a payload for capturing an image comprising at least one of an electro-optical (EO) payload, a synthetic aperture radar (SAR) payload, and a hyperspectral payload, wherein discharge current of a certain magnitude is generated from the battery during the satellite mission execution period. ### Claim 4 (depends on 3) The method of claim 3, further comprising: when constant current of a same magnitude as the discharge current is discharged from a new battery, storing, as the first reference voltage difference, a difference between a voltage value of the new battery immediately before the discharge starts and a voltage value of the new battery when the reference time elapses after the discharge starts; and when constant current of a same magnitude as the discharge current is discharged from an aging battery, storing, as the second reference voltage difference, a difference between a voltage value of the aging battery immediately before the discharge starts and a voltage value of the aging battery when the reference time elapses after the discharge starts. ### Claim 5 (depends on 1) The method of claim 1, wherein the estimating of the aging amount of the battery of the satellite comprises estimating the aging amount of the battery based on a ratio of a difference between the second reference voltage difference and the sensing voltage difference with respect to a difference between the second reference voltage difference and the first reference voltage difference. ### Claim 6 (depends on 1) The method of claim 1, further comprising determining whether the satellite is located in a daylight period in which sunlight is irradiated onto the satellite during the precise sensing period based on orbit information of the satellite, wherein, when the satellite is located in the daylight period during the precise sensing period, the obtaining of the first battery voltage value and the second battery voltage value and the estimating of the aging amount of the battery of the satellite are performed. ### Claim 7 (depends on 1) The method of claim 1, wherein the satellite detects a voltage and current of the battery in a second sensing period longer than the first sensing period during a normal sensing period excluding the precise sensing period. ### Claim 8 (depends on 1) The method of claim 1, wherein the battery of the satellite comprises m×n battery cells that are connected in series and in parallel, where m is a number of series connections of the battery cells and n is a number of parallel connections of the battery cells, wherein each of the battery cells is expressed as an equivalent circuit model comprising an open circuit voltage source (OCV), an ohmic resistor (RI), a polarization resistor (Rd), and a polarization capacitor (Cd), wherein the sensing voltage difference (ΔVsen) is expressed as ΔVsen/Imission=(m/n)×RI+(1−e−ατ)×β, where β=(m/n)×Rd, α=(Rd×Cd)−1, τ is the reference time, and Imission is a magnitude of discharge current of a certain magnitude generated in the battery during the satellite mission execution period. ### Claim 9 (depends on 8) The method of claim 8, further comprising: obtaining at least one third battery voltage value of at least one time point between the first time point and the second time point based on the battery voltage data; and estimating the ohmic resistor (RI), the polarization resistor (Rd), and the polarization capacitor (Cd) of the battery cell, by using the first and second battery voltages and the at least one third battery voltage. ### Claim 10 An apparatus for estimating an aging amount of a battery mounted on a satellite that performs a satellite mission, the apparatus comprising: a processor; and a memory, wherein the processor is configured to receive battery voltage and current data generated by detecting a voltage and current of the battery in a preset first sensing period during a precise sensing period from the satellite and store the battery and current data in the memory, determine a mission start time point when the satellite begins to perform the satellite mission based on the battery current data, obtain a first battery voltage value of a first time point immediately before the satellite performs the satellite mission based on the battery voltage data and the mission start time point, obtain a second battery voltage of a second time point when a preset reference time elapses from the first time point based on the battery voltage data, and estimate an aging amount of the battery of the satellite based on a sensing voltage difference that is a difference between the first battery voltage value and the second battery voltage value, a first reference voltage difference, and a second reference voltage difference. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the satellite performs the satellite mission by using a payload for capturing an image comprising at least one of an electro-optical (EO) payload, a synthetic aperture radar (SAR) payload, and a hyperspectral payload, wherein discharge current of a certain magnitude is generated from the battery during a satellite mission execution period in which the satellite performs the satellite mission. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the memory is configured to, when current state of a same magnitude as the discharge current is discharged from a new battery, store, as the first reference voltage difference, a difference between a voltage value of the new battery immediately before the discharge starts and a voltage value of the new battery when the reference time elapses after the discharge starts, and when constant current of a same magnitude as the discharge current is discharged from an aging battery, store, as the second reference voltage difference, a difference between a voltage value of the aging battery immediately before the discharge starts and a voltage value of the aging battery when the reference time elapses after the discharge starts. ### Claim 13 (depends on 10) The apparatus of claim 10, wherein the processor is further configured to estimate the aging amount of the battery based on a ratio of a difference between the second reference voltage difference and the sensing voltage difference with respect to a difference between the second reference voltage difference and the first reference voltage difference. ### Claim 14 (depends on 10) The apparatus of claim 10, wherein the battery of the satellite comprises m×n memory cells that are connected in series and in parallel, where m is a number of series connections of the battery cells and n is a number of parallel connections of the battery cells, wherein each of the battery cells is expressed as an equivalent circuit model comprising an open circuit voltage source (OCV), an ohmic resistor (RI), a polarization resistor (Rd), and a polarization capacitor (Cd), wherein the sensing voltage difference (ΔVsen) is expressed as ΔΔVsen/Imission=(m/n)×RI+(1−e−ατ)×β, where β=(m/n)×Rd, α=(Rd×Cd)−1, τ is the reference time, and Imission is a magnitude of discharge current of a certain magnitude generated in the battery during a satellite mission execution period. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the processor is further configured to obtain at least one third battery voltage value of at least one time point between the first time point and the second time point based on the battery voltage data, and estimate the ohmic resistor (RI), the polarization resistor (Rd), and the polarization capacitor (Cd) of the battery cell, by using the first and second battery voltages and the at least one third battery voltage.