Patent US3185393A successfully refreshed from Google Patents.
EP0206503A2
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Method and apparatus for determining the state of charge of a battery
Assignee: Jaguar Land Rover Ltd
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Filing: 1986-05-15
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Granted: —
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Expires: 2006-05-15
Abstract
Abstract A method of determining the state of charge of a motor vehicle battery (1) in which a stabilization load (2) is applied to the battery (1) after the engine is switched off to accelerate the stabilization of the charge distribution within the battery (1). The stabilization load (2) is applied until the terminal voltage of the battery (1) reaches a level corresponding to a predicted value of the state of charge of the battery (1) After a pre-determined delay of 8 hours or less, the terminal voltage of the battery (1) is measured and the state of charge derived therefrom.
Inventors
- 👤 Malcolm Williams
- 👤 Carmichael Mackie
- 👤 Peter Watson Barbour
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 05:19
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/36; G01R31/385; G01R31/386; G01R31/382; G01R31/3835; H; H02; H02J; H02J7/00; H02J7/90; H02J7/96
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
83 words
A method of determining the state of charge of a battery comprising the steps of: applying a load to the battery to accelerate stabilization of the charge distribution therein after any charging or discharging current passing through the battery has fallen below a given level; measuring the terminal voltage of the battery after the said load has been removed; and evaluating the state of charge from stored data on the relationship between the terminal voltage and the state of charge of the battery.
Claim 2
Independent Claim
83 words
A method of determining the state of charge of a battery comprising the steps of: applying a load to the battery to accelerate stabilization of the charge distribution therein after any charging or discharging current passing through the battery has fallen below a given level; measuring the terminal voltage of the battery after the said load has been removed; and evaluating the state of charge from stored data on the relationship between the terminal voltage and the state of charge of the battery.
Claim 3
Dependent Claim
53 words
A method as claimed in claim 1 in which the current passing through the battery is measured whilst it is being charged and discharged to estimate the variation in the state of charge since the previous determination thereof and thus to provide a predicted value of the state of charge of the battery.
Claim 4
Dependent Claim
47 words
A method as claimed in claim 2 in which the said load is applied to the battery for a period of time such that the terminal voltage thereof is brought to a level substantially corresponding to the predicted value of the state of charge of the battery.
Claim 5
Dependent Claim
49 words
A method as claimed in claim 2 or 3 in which the temperature of the battery is measured and the predicted value of the state of charge of the battery is modified in accordance with stored data on the relationship between temperature and the charge efficiency of the battery.
Claim 6
Independent Claim
33 words
A method as claimed in any preceding claim in which there is a pre-determined time delay between removal of the said load on the battery and the measurement of the terminal voltage thereof.
Claim 7
Dependent Claim
18 words
A method as claimed in claim 5 in which the pre-determined time delay is 8 hours or less.
Claim 8
Independent Claim
54 words
A method as claimed in any preceding claim in which the terminal voltage of the battery is measured when no substantial current is passing therethrough and the state of charge is evaluated from stored data on the direct relationship between the terminal voltage in such conditions and the state of charge of the battery.
Claim 9
Dependent Claim
46 words
A method as claimed in claim 7 in which the temperature of the battery is measured and the state of charge of the battery is evaluated from stored data on the relationships between the terminal voltage, the temperature and the state of charge of the battery.
Claim 10
Independent Claim
56 words
A method as claimed in any of claims 1 to 6 in which the terminal voltage of the battery is measured when a known current is drawn therefrom and the state of charge is evaluated from stored data on the relationships between the drawn current, the terminal voltage and the state of charge of the battery.
Claim 11
Dependent Claim
49 words
A method as claimed in claim 9 in which the temperature of the battery is measured and the state of charge of the battery is evaluated from stored data on the relationships between the drawn current, the terminal voltage, the temperature and the state of charge of the battery.
Claim 12
Independent Claim
35 words
A method as claimed in any preceding claim in which the stored data used to evaluate the state of charge of the battery is selected in accordance with the characteristics of the battery being tested.
Claim 13
Dependent Claim
31 words
A method as claimed in claim 11 in which the characteristics of the battery being tested are determined by measurements of the terminal voltage and of current drawn from the battery.
Claim 14
Independent Claim
29 words
A method as claimed in any preceding claim in which the load applied to the battery is approximately 10 amps and is applied for between 2 and 5 minutes.
Claim 15
Independent Claim
58 words
A method of determining the state of charge of a battery of a motor vehicle as claimed in any preceding claim in which the said given level is such that the said load is applied to the battery when the engine of the vehicle is switched off and any remaining discharging current is due only to permanent loads.
Claim 16
Dependent Claim
41 words
A method of determining the state of charge of a battery in which the state of charge is selectively evaluated in accordance with claim 7 or any claim dependent thereon or in accordance with claim 9 or any claim dependent thereon.
Claim 17
Independent Claim
53 words
A method of controlling the charging of a battery in which the state of charge thereof is determined in accordance with any preceding claim and the charging current is substantially reduced or switched off when the evaluated state of charge reaches a pre-determined level to thereby prevent thermal run away of the battery.
Claim 18
Independent Claim
12 words
A method substantially as hereinbefore described with reference to the accompanying drawings.
Claim 19
Independent Claim
12 words
A method substantially as hereinbefore described with reference to the accompanying drawings.
Claim 20
Dependent Claim
91 words
Apparatus for determining the state of charge of a battery comprising: stabilization means arranged to apply a load to the battery to accelerate stabilization of the charge distribution therein after any charging or discharging current passing through the battery has fallen below a given level; measuring means arranged to measure the terminal voltage of the battery after the said load has been removed; and evaluating means arranged to evaluate the state of charge from stored data on the relationship between the terminal voltage and the state of charge of the battery.
Claim 21
Dependent Claim
91 words
Apparatus for determining the state of charge of a battery comprising: stabilization means arranged to apply a load to the battery to accelerate stabilization of the charge distribution therein after any charging or discharging current passing through the battery has fallen below a given level; measuring means arranged to measure the terminal voltage of the battery after the said load has been removed; and evaluating means arranged to evaluate the state of charge from stored data on the relationship between the terminal voltage and the state of charge of the battery.
Claim 22
Dependent Claim
54 words
Apparatus as claimed in claim 18 comprising monitoring means arranged to measure the current passing through the battery whilst it is being charged or discharged to estimate the variation in the state of charge since the previous determination thereof and arranged to provide a predicted value of the state of charge of the battery.
Claim 23
Dependent Claim
39 words
Apparatus as claimed in claim 17 comprising control means arranged to remove the said load on the battery when the measured terminal voltage reaches a level corresponding to the predicted value of the state of charge of the battery.
Claim 24
Dependent Claim
54 words
Apparatus as claimed in claim 18, 19 or 20 comprising sensing means arranged to sense the temperature of the battery and in which the evaluating means is arranged to evaluate the state of charge from stored data on the relationships between the terminal voltage, the temperature and the state of charge of the battery.
Claim 25
Dependent Claim
50 words
A motor vehicle having apparatus as claimed in any of claims 18 - 21 in which the stabilization means is arranged to apply the said load to the battery when the engine of the motor vehicle is switched off and any remaining discharging current is due only to permanent loads.
Claim 26
Dependent Claim
31 words
A motor vehicle as claimed in claim 22 comprising indicating means for providing the driver with an indication of the most recent evaluation of the state of charge of the battery.
References Cited (Backward Citations)
No citation records indexed.
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