Apparatus and method for detecting a status of a secondary battery connected to a load
First Claim
1. A battery status detecting method performed by a battery status detecting apparatus that is connected to a secondary battery to detect a battery status of the secondary battery that supplies power to an electrical load, the method comprising:
- a current measuring step of measuring a discharge current value of the secondary battery; and
an estimating step of the battery status detecting apparatus estimating a dischargeable capacity or a dischargeable time of the secondary battery that is defined as a capacity or time dischargeable with the measured discharge current value before a voltage of the secondary battery drops to a predetermined voltage specified by the electrical load, the estimating being performed based on discharge characteristics of the secondary battery, the discharge characteristics indicating relationships between a discharge capacity and a discharge rate that are observed when the voltage of the secondary battery drops to the predetermined voltage specified by the electrical load,wherein the discharge characteristics indicate a relationship between a discharge capacity and the discharge current value of the secondary battery,and whereinthe discharge characteristics are represented by an expression described as;
Q=A·
I+B·
ln (I)+C−
(FCC−
remaining capacity)or
Q=A′
·
I+B′
·
(1/I)+C′
−
(FCC−
remaining capacity)where Q represents the dischargeable capacity of the secondary battery, I represents the discharge current value of the secondary battery, FCC represents a full charge capacity of the secondary battery, A, B, and C represent coefficients of the expression, and A′
, B′
, and C′
represent coefficients of the expression.
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Accused Products
Abstract
A battery status detecting method for detecting a battery status of a secondary battery that supplies power to an electrical load is disclosed. This method includes measuring a discharge current value of the secondary battery, and estimating the dischargeable capacity or the dischargeable time of the secondary battery with the measured discharge current value based on discharge characteristics of the secondary battery indicating the discharge status of the secondary battery when the voltage of the secondary battery drops to a predetermined voltage specified by the electrical load.
16 Citations
12 Claims
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1. A battery status detecting method performed by a battery status detecting apparatus that is connected to a secondary battery to detect a battery status of the secondary battery that supplies power to an electrical load, the method comprising:
-
a current measuring step of measuring a discharge current value of the secondary battery; and an estimating step of the battery status detecting apparatus estimating a dischargeable capacity or a dischargeable time of the secondary battery that is defined as a capacity or time dischargeable with the measured discharge current value before a voltage of the secondary battery drops to a predetermined voltage specified by the electrical load, the estimating being performed based on discharge characteristics of the secondary battery, the discharge characteristics indicating relationships between a discharge capacity and a discharge rate that are observed when the voltage of the secondary battery drops to the predetermined voltage specified by the electrical load, wherein the discharge characteristics indicate a relationship between a discharge capacity and the discharge current value of the secondary battery, and wherein the discharge characteristics are represented by an expression described as;
Q=A·
I+B·
ln (I)+C−
(FCC−
remaining capacity)or
Q=A′
·
I+B′
·
(1/I)+C′
−
(FCC−
remaining capacity)where Q represents the dischargeable capacity of the secondary battery, I represents the discharge current value of the secondary battery, FCC represents a full charge capacity of the secondary battery, A, B, and C represent coefficients of the expression, and A′
, B′
, and C′
represent coefficients of the expression. - View Dependent Claims (2, 3)
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4. A battery status detecting apparatus that detects a battery status of a secondary battery that supplies power to an electrical load, the apparatus comprising:
-
a storage unit that stores characteristics data used for determining secondary battery discharge characteristics, the characteristics data indicating relationships between a discharge capacity and a discharge rate that are observed when a voltage of the secondary battery drops to a predetermined voltage specified by the electrical load; and an estimating unit that estimates a dischargeable capacity or a dischargeable time of the secondary battery that is defined as a capacity or time dischargeable before the voltage of the secondary battery drops to the predetermined voltage specified by the electrical load, the estimating being pet-formed using the characteristics data stored in the storage unit, wherein the discharge characteristics indicate a relationship between a discharge capacity and a discharge current value of the secondary battery, and wherein the discharge characteristics are represented by an expression described as;
Q=A ·
I+B·
ln (I)+C−
(FCC−
remaining capacity)or
Q=A′
·
I+B′
·
(1/I)+C′
−
(FCC−
remaining capacity)where Q represents the dischargeable capacity of the secondary battery, I represents the discharge current value of the secondary battery, FCC represents a full charge capacity of the secondary battery, A, B, and C represent coefficients of the expression, and A′
, B′
, and C′
represent coefficients of the expression; andthe characteristics data include data for determining values of the coefficients A, B, and C or data for determining values of the coefficients A′
, B′
, and C′
. - View Dependent Claims (5, 6)
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7. An expression deriving method for deriving a dischargeable capacity computing expression for computing a dischargeable capacity of a secondary battery that supplies power to an electrical load, the method comprising:
-
a measuring step of measuring first discharge characteristics indicating a relationship between a voltage and a discharge capacity of the secondary battery, the first discharge characteristics being measured with respect to a plurality of discharge current values of the secondary battery; a converting step of converting the first discharge characteristics into second discharge characteristics indicating a relationship between the discharge capacity and the discharge current value of the secondary battery when the voltage of the secondary battery drops to a predetermined voltage specified by the electrical load; an expression deriving step of deriving the dischargeable capacity computing expression based on the second discharge characteristics of the secondary battery; storing data indicative of the derived dischargeable capacity computing expression in a memory of a battery status detecting apparatus that detects a battery status of the secondary battery; and configuring the battery status detecting apparatus such that the battery status detecting apparatus detects the battery status of the secondary battery based on the dischargeable capacity computing expression stored in the memory. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification