Detecting method for detecting internal state of a rechargeable battery, detecting device for practicing said detecting method, and instrument provided with said detecting device
First Claim
1. A detecting method for detecting an internal state of an inspective rechargeable battery (Ba), said internal state including a deterioration state, an electricity storable capacity, a remaining capacity, and an internal resistance of said inspective rechargeable battery (Ba), said detecting method comprising:
- (1) a step in which basic data (BD) of characteristics of a normal non-deteriorated rechargeable battery (Bn) as a reference rechargeable battery for said inspective rechargeable battery (Ba) are provided; and
(2) a step in which for said inspective rechargeable battery (Ba), a voltage value or/and a current value thereof are measured, and the measured result is compared with said basic data (BD) obtained in said step (1) to judge;
(i) the inspective rechargeable battery (Ba) is short-circuited, (ii) the internal resistance of the inspective rechargeable battery (Ba) is increased, (iii) the electricity storable capacity of the inspective rechargeable battery (Ba) is decreased, (iv) the electricity storable capacity of the rechargeable battery (Ba) is decreased and the internal resistance thereof is increased, or (v) the inspective rechargeable battery (Ba) is normal.
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Abstract
A detecting method for detecting an internal state of an inspective rechargeable battery (Ba), said internal state including a deterioration state, an electricity storable capacity, a remaining capacity, and an internal resistance of said inspective rechargeable battery (Ba), comprising: (1) a step in which basic data (BD) of characteristics of a normal non-deteriorated rechargeable battery (Bn) as a reference rechargeable battery for said inspective rechargeable battery (Ba) are provided; and (2) a step in which for said inspective rechargeable battery (Ba), a voltage value or/and a current value thereof are measured, and the measured result is compared with said basic data (BD) obtained in said step (1) to judge whether or not said inspective rechargeable battery (Ba) is of a deterioration mode and to detect the internal state thereof.
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Citations
85 Claims
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1. A detecting method for detecting an internal state of an inspective rechargeable battery (Ba), said internal state including a deterioration state, an electricity storable capacity, a remaining capacity, and an internal resistance of said inspective rechargeable battery (Ba),
said detecting method comprising: -
(1) a step in which basic data (BD) of characteristics of a normal non-deteriorated rechargeable battery (Bn) as a reference rechargeable battery for said inspective rechargeable battery (Ba) are provided; and
(2) a step in which for said inspective rechargeable battery (Ba), a voltage value or/and a current value thereof are measured, and the measured result is compared with said basic data (BD) obtained in said step (1) to judge;
(i) the inspective rechargeable battery (Ba) is short-circuited, (ii) the internal resistance of the inspective rechargeable battery (Ba) is increased, (iii) the electricity storable capacity of the inspective rechargeable battery (Ba) is decreased, (iv) the electricity storable capacity of the rechargeable battery (Ba) is decreased and the internal resistance thereof is increased, or (v) the inspective rechargeable battery (Ba) is normal. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85)
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3. The detecting method according to claim 1 or 2, wherein said basic data (BD) are averaged basic data obtained by subjecting said normal non-deteriorated rechargeable battery (Bn) to charging and discharging under various temperature conditions and at various rates of charge or discharge where the battery voltages, and the remaining capacities or the discharged electricity quantities of the normal rechargeable battery (Bn) are measured and averaging the measured battery voltages and the measured remaining capacities or the measured discharged electricity quantities of the normal rechargeable battery (Bn).
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4. The detecting method according to claim 1 or 2, wherein said basic data (BD) are basic data previously obtained by way of computer simulation.
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5. The detecting method according to claim 3, wherein said basic data are obtained by way of computer simulation on the basis of said averaged basic data (BD).
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6. The detecting method according to claim 1 or 2, wherein the inspective rechargeable battery (normal non-deteriorated rechargeable battery (Ba) is judged of whether or nor it is short-circuited, then the inspective rechargeable battery (normal non-deteriorated rechargeable battery (Ba) is judged of whether or not the electricity storable capacity of the battery is decreased or whether or not the internal resistance of the battery is increased.
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7. The detecting method according to claim 1 or 2, wherein:
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(1) the inspective rechargeable battery (Ba) is judged to be short-circuited when the battery falls in any of the following cases (i) to (iv);
(i) a case where when the inspective rechargeable battery (Ba) is paused without subjecting to charging or discharging, the battery has a decrease with the passage of time in the open-circuit voltage, (ii) a case where upon charging, an increase in the battery voltage or open-circuit voltage of the inspective rechargeable battery (Ba) is smaller than that of the normal rechargeable battery (Bn) which is corresponding to the inspective rechargeable battery (Ba), (iii) a case where in comparison with the normal rechargeable battery (Bn), the open-circuit voltage of the inspective rechargeable battery (Ba) is smaller than that of the normal rechargeable battery (Bn) and a decrease in the battery voltage of the inspective rechargeable battery (Ba) upon discharging is greater than that of the normal rechargeable battery (Bn), and (iv) a case where the internal resistance of the inspective rechargeable battery (Ba) is smaller than that of the normal rechargeable battery (Bn);
(2) when the inspective rechargeable battery (Ba) is judged to be not short-circuited in the judgment (1) but it falls in any of the following cases (i) to (iii), the inspective rechargeable battery (Ba) is judged that the internal resistance is increased;
(i) a case where the open-circuit voltage of the inspective rechargeable battery (Ba) is substantially the same as that of the normal rechargeable battery (Bn) but an increase in the battery voltage of the former upon charging is greater than that of the latter, (ii) a case where the open-circuit voltage of the inspective rechargeable battery (Ba) is substantially the same as that of the normal rechargeable battery (Bn) but a decrease in the battery voltage of the former upon discharging is greater than that of the latter, and (iii) a case where the internal resistance of the inspective rechargeable battery (Ba) is greater than that of the normal rechargeable battery (Bn);
(3) when the inspective rechargeable battery (Ba) is judged to be not short-circuited in the judgment (1) but it falls in any of the following cases (i) and (ii), the inspective rechargeable battery (Ba) is judged that the electricity storable capacity is decreased;
(i) a case where an increase in the battery voltage of the inspective rechargeable battery (Ba) upon charging and an increase in the open-circuit voltage thereof after the charging are greater than those of the normal rechargeable battery (Bn), and (ii) a case where a decrease in the battery voltage of the inspective rechargeable battery (Ba) upon discharging and a decrease in the open-circuit voltage thereof after the discharging are smaller than those in a case where the inspective rechargeable battery (Ba) is short-circuited but they are greater than those of the normal rechargeable battery (Bn); and
(4) when the inspective rechargeable battery (Ba) does not fall in any of the cases mentioned in the above judgments (1) to (3), it is judged to be normal.
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8. The detecting method according to claim 1 or 2, wherein said basic data (BD) include one or more of data or function formulas selected from those mentioned in the following (1) to (5):
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(1) for a non-deteriorated normal rechargeable battery, basic data of a relationship Voc(Q) or Q(Voc) of the open-circuit voltage (Voc) to the remaining capacity (Q) which are obtained by way of measurement or function formulas obtained on the basis of said data;
(2) for said non-deteriorated normal rechargeable battery when it is in a full-charged state, basic data of relationships between battery voltages (Vd) measured when the rechargeable battery is subjected to discharging at various battery temperatures (T) and at various discharging currents (Id), open-circuit voltages (Voc) measured when the discharging is temporarily suspended, said discharging currents (Id) and said battery temperatures (T) or a function formula Vd(Voc, Id, T) obtained on the basis of said data; and
basic data or a function formula of a battery voltage-related function formula Vd(Q, Id, T)or Q(Vd, Id, T) obtained with reference to aforesaid data and aforesaid function formula and also with reference to the data or the function formula of the relationship Voc(Q) of the open-circuit voltage (Voc) to the remaining capacity which are described in the above (1);
(3) internal resistance-related basic data computed from a relation expression Vd=Voc−
Id×
Rd or Rd=(Voc−
Vd)/Id when the internal resistance of the normal rechargeable battery is made to be Rd in the above (2), or a function formula Rd(Voc, Id, T) or Rd(Vd, Id, T) obtained on the basis of said data, in addition, basic data or a function formula of an internal resistance-related function formula Rd(Q, Id, T) or Q(Rd, Id, T) obtained with reference to aforesaid data and aforesaid function formula and also with reference to the data or the function formula of the relationship Voc(Q) of the open-circuit voltage (Voc) which are described in the above (1);
(4) for the above non-deteriorated normal rechargeable battery when the remaining capacity thereof is zero, data of relationships between battery voltages (Vc) measured when the rechargeable battery is subjected to charging at various battery temperatures (T) and at various charging currents (Ic), open-circuit voltages (Voc) measured when the charging is temporarily suspended, said discharging currents (Ic) and said battery temperatures (T) or a function formula Vc(Voc, Ic, T) obtained on the basis of said data, in addition, data or a function formula of a battery voltage-related function formula Vc(Q, Ic, T) or Q(Vc, Ic, T) obtained with reference to aforesaid data and aforesaid function formula and also with reference to the data or the function formula of the relationship Voc(Q) of the open-circuit voltage (Voc) which are described in the above (1);
(5) internal resistance-related data computed from a relation expression Vc=Voc+Ic×
Rc or Rc=(Vc−
Voc)/Ic when the internal resistance of the normal rechargeable battery is made to be Rc in the above (4), or a function formula Rc(Voc, Ic, T) obtained on the basis of said data, in addition, data or a function formula of an internal resistance-related function formula Rc(Q, Ic, T) or Q(Rc, Ic, T) obtained with reference to aforesaid data and aforesaid function formula and also with reference to the data or the function formula of the relationship Voc(Q) of the open-circuit voltage (Voc) which are described in the above (1).
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9. The detecting method according to claim 1 or 2, wherein when the inspective rechargeable battery (Ba) is in a paused state, a change with the passage of time in open-circuit voltage (Voc) thereof is measured;
- the inspective rechargeable battery (Ba) is judged to be short-circuited when a decrease rate (−
dVoc/dt) of the Voc is greater than a prescribed value v0, that is, −
dVoc/dt>
v0>
0, and the inspective rechargeable battery (Ba) is judged to be not short-circuited when said increase rate of the Voc is 0≦
−
dVoc/dt≦
v0.
- the inspective rechargeable battery (Ba) is judged to be short-circuited when a decrease rate (−
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10. The detecting method according to claim 8, wherein when the inspective rechargeable battery (Ba) is in a paused state without subjecting to charging or discharging, with reference to the data or relation expression of the relation Q(Voc), a remaining capacity of said rechargeable battery is computed.
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11. The detecting method according to claim 8 or 10, wherein when the inspective rechargeable battery (Ba) is in a paused state without subjecting to charging or discharging, said rechargeable battery is judged of whether the battery is normal or deteriorated by measuring a change with the passage of time in the open-circuit voltage (Voc), discharging an electricity quantity q1 of a current value×
- a time t1 from the measured open-circuit voltage, and measuring a battery voltage (V) of said battery duration until said discharging is terminated and an open-circuit voltage (Voc) of said battery after the termination of the discharging.
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12. The detecting method according to claim 11, wherein judgment of the inspective rechargeable battery (Ba) is performed as will be described below:
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(1) when a decrease rate (−
dVoc/dt) of the open-circuit voltage (Voc) is greater than a prescribed value v0, that is, −
dVoc/dt>
v0>
0, the inspective rechargeable battery (Ba) is judged to be not short-circuited;
(2) when the inspective rechargeable battery (Ba) does not correspond to the above (1), with reference to the basic data mentioned in (1) of claim 8, a remaining capacity Q0=Q(Voc0) when the open-circuit voltage of the normal rechargeable battery (Bn)is Voc0 is estimated and an open-circuit voltage Voc=Voc(Q0−
q1) of the normal rechargeable battery is estimated when an electricity quantity q1 is discharged from Q0, and when a difference between the open-circuit voltage Voc(Q0−
q1) of the normal rechargeable battery (Bn) and the measured open-circuit voltage Voc1 of the inspective rechargeable battery (Ba) is f0≦
[Voc(Q0−
q1)−
Voc1]≦
f1(f0<
0<
f1) which is an allowable variation range of the characteristics of the normal rechargeable battery (Bn) as a product, the inspective rechargeable battery (Ba) is judged to be free of a decrease in the electricity storable capacity; and
by assuming that transient characteristics of the battery voltage of the inspective rechargeable battery at an initial stage when discharging for the inspective rechargeable battery is initiated can be expressed by an equation V=V1+(Voc0−
V1)×
e−
t/τ
(with V being a battery voltage, t being a discharging time, V1 being a battery voltage of the battery when the discharging time is extrapolated to infinity, and τ
being a time constant decided by an internal resistance or the like of the battery), in accordance with the battery voltage V to a measured discharging time and in accordance with said equation, a time constant τ
when the discharging is initiated at a discharging current I1 from the open-circuit voltage Voc0 and a battery voltage V1 are computed where when the internal resistance of the inspective rechargeable battery is made to be R1, there is obtained an equation V1=Voc0−
I1×
R1 or R1=(Voc0−
V1)/I1;
in accordance with this equation, an internal resistance R1 of the Ba inspective rechargeable battery (Ba)is estimated, and this internal resistance R1 of the inspective rechargeable battery (Ba) is compared with the internal resistance Rd(Voc0, I1, T)[or Rd(Q0, I1, T)] of the normal rechargeable battery (Bn) which is obtained from the function formula Rd(Voc, Id, T) or Rd(Q0, Id, T) mentioned in (3) of claim 8, where judgment is performed as will be described below,(i) when the internal resistance R1 of the inspective rechargeable battery (Ba) is substantially the internal resistance Rd(Voc0, I1, T) or Rd(Q0, I1, T) of the normal rechargeable battery (Bn), in other words, when the internal resistance R1 of the inspective rechargeable battery (Ba)falls in an allowable variation range of r1≦
[R1−
Rd(Q0, I1, T)]≦
r2(r1<
0<
r2) for the normal rechargeable battery (Bn) as a product, the inspective rechargeable battery (Ba)is judged that it is normal, and(ii) when the internal resistance R1 of the inspective rechargeable battery (Ba) falls in a variation range of [R1−
Rd(Q0, I1, T)]>
r2(0<
r2), the inspective rechargeable battery (Ba) is judged that the internal resistance is increased; and
(3) when the inspective rechargeable battery (Ba) does not correspond to the above (1) and a difference between the open-circuit voltage Voc(Q0−
q1) of the normal rechargeable battery (Bn) and the measured open-circuit voltage Voc1 of the inspective rechargeable battery (Ba) is in a range of [Voc(Q0−
q1)−
Voc1]>
f1(0<
f1), the inspective rechargeable battery (Ba) is judged that the electricity storable capacity is decreased.
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13. The detecting method according to claim 12, wherein in the judgment (2)-(ii) of claim 12, when the inspective rechargeable battery (Ba) is judged that the internal resistance is increased, for the inspective rechargeable battery, an electricity quantity q2 of a current value I2×
- a time t2 is discharged from the open-circuit voltage Voc1, where a battery voltage duration until the discharging operation is terminated and an open-circuit voltage Voc2 after the termination of the discharging operation are measured, then by assuming that transient characteristics of the battery voltage of the inspective rechargeable battery (Ba) at a initial stage of the commencement of the discharging operation can be expressed by an equation V=V2+(Voc1−
V2)×
e−
t/τ
(with V being a battery voltage, t being a discharging time, V2 being a battery voltage of the battery when the discharging time t is extrapolated to infinity, and τ
being a time constant), in accordance with the battery voltage V to a measured discharging time and in accordance with said equation, a time constant τ
when the discharging operation is initiated at a discharging current I2 from the open-circuit voltage Voc1 and a battery voltage V2 are computed, then an internal resistance R2 of the inspective rechargeable battery at this time is computed from an equation V2=Voc1−
I2×
R2 or R2=(Voc1−
V2)/I2, successively by assuming that the internal resistance of the inspective rechargeable battery (Ba) is increased from the internal resistance Rd(Q, Id, T) of the normal rechargeable battery (Bn) to a×
Rd(Q, Id, T)+b (where each of a and b is a constant) and in accordance with an equation R1−
[a×
Rd(Q0, I1, T)+b]=0 (where each of a and b is a constant) and an equation R2−
[a×
Rd(Q0−
q1, I2, T)+b]=0 (where each of a and b is a constant) or an equation R2−
[a×
Rd(Q1, I2, T)+b]=0 (where each of a and b is a constant) using Q1=Q0−
q1=Q(Voc1), the constant a and the constant b are computed to estimate a value of the increased internal resistance Rd′
=a×
Rd(Q, Id, T)+b.
- a time t2 is discharged from the open-circuit voltage Voc1, where a battery voltage duration until the discharging operation is terminated and an open-circuit voltage Voc2 after the termination of the discharging operation are measured, then by assuming that transient characteristics of the battery voltage of the inspective rechargeable battery (Ba) at a initial stage of the commencement of the discharging operation can be expressed by an equation V=V2+(Voc1−
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14. The detecting method according to claim 12, wherein in the judgment (3) of claim 12, when the inspective rechargeable battery (Ba) is judged that the electricity storable capacity is decreased, by assuming that the electricity storable capacity C′
- of the inspective rechargeable battery is D time the electricity storable capacity C of the normal rechargeable battery (where D is a constant and is 0<
D<
1) and making the remaining capacity Q0′
of the inspective rechargeable battery to be Q0′
=Q0×
D (where Q0 is a remaining capacity of the normal rechargeable battery (Bn), and D is a constant and is 0<
D<
1) and with reference to the remaining capacity Q0 of the normal rechargeable battery which is corresponding to the open-circuit voltage Voc0 of the inspective rechargeable battery, the remaining capacity Q0′
=Q0×
D of the inspective rechargeable battery, the remaining capacity Q1 of the normal rechargeable battery which is corresponding to the open-circuit voltage Voc1 of the inspective rechargeable battery, and the remaining capacity Q1′
=Q0′
−
Q1×
D of the inspective rechargeable battery and also with reference to function formulas Voc(Q)=Voc(Q0′
/D)=Voc0 and Voc(Q1)=Voc(Q1′
/D)=Voc(Q0′
/D−
q1/D)=Voc1 which are obtained on the basis of the basic data mentioned in (1) of claim 8, a value of the constant D and a value of the remaining capacity Q1′
=Q0′
−
q1=Q1×
D are estimated, where judgment of the inspective rechargeable battery is performed as will be described below,(i) when a difference between the internal resistance R1 computed in the (2) of claim 12 and an internal resistance Rd(Q0′
/D, I1, T) estimated from the above basic data falls in a range of r1≦
[R1−
Rd(Q0′
/D, I1, T)]≦
r2(r1<
0<
r2), the inspective rechargeable battery is judged that the internal resistance is not increased but the electricity storable capacity is decreased, and(ii) when said difference falls in a range of [R1−
Rd(Q0′
/D, I1, T)]>
r2(0<
r2), the inspective rechargeable battery is judged that the internal resistance is increased and the electricity storable capacity is decreased;
then, for the inspective rechargeable battery, an electricity quantity q1 of a current value I1×
a time t1 is discharged from the open-circuit voltage Voc0, followed by discharging an electricity quantity q2 of a current value I2×
a time t2, where a battery voltage of the inspective rechargeable battery duration until the discharging operation is terminated and an open-circuit voltage Voc2 after the termination of the discharging operation are measured, and by assuming that transient characteristics of the battery voltage of the inspective rechargeable battery at a initial stage of the commencement of the discharging operation can be expressed by an equation V=V2+(Voc1−
V2)×
e−
t/τ
(with V being a battery voltage, t being a discharging time, V2 being a battery voltage of the battery when the discharging time t is extrapolated to infinity, and τ
being a time constant), in accordance with the battery voltage V to a measured discharging time and in accordance with said equation, a time constant τ
when the discharging operation is initiated at a discharging current I2 from the open-circuit voltage Voc1 and a battery voltage V2are computed, then an internal resistance R2 of the inspective rechargeable battery at this time is computed from an equation V2=Voc1−
I2×
R2 or R2=(Voc1−
V2)/I2, successively by assuming that the internal resistance of the inspective rechargeable battery is increased from the internal resistance Rd(Q, Id, T) of the normal rechargeable battery to a×
Rd(Q, Id, T)+b (where each of a and b is a constant) and in accordance with an equation R1−
[a×
Rd(Q0, I1, T)+b]=0 (where each of a and b is a constant) and an equation R2−
[a×
Rd(Q1, I2, T)+b]=R2−
[a×
Rd(Q0−
q1/D, I2, T)+b]=0 (where each of a and b is a constant)[where Q0=Q0′
/D, Q1=Q1′
−
q1=Q1′
/D, and Q0′ and
Q1′
are a remaining capacity when the open-circuit voltage is Voc0 and a remaining capacity when the open-circuit voltage is Voc1 respectively], the constant a and the constant b are computed to estimate a value of the increased internal resistance Rd′
=a×
Rd(Q′
/D, Id, T)+b (where Q′
is a true remaining capacity when the electricity storable capacity is decreased) of the inspective rechargeable battery, whereby a deteriorated state and a remaining capacity of the inspective rechargeable are capable of being detected.
- of the inspective rechargeable battery is D time the electricity storable capacity C of the normal rechargeable battery (where D is a constant and is 0<
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15. The detecting method according to claim 8 to 10, wherein for the inspective rechargeable battery which is in a paused state without subjecting to charging or discharging, after an open-circuit voltage Voc thereof is measured, charging for said rechargeable battery is started at a charging voltage Ic1 where a battery voltage Vc of the battery is measured, followed by charging an electricity quantity q1 of a time t1×
- a charge-and-discharge efficiency Eff where the charging operation is terminated when the battery voltage of the battery becomes Vc1, where a change with the passage of time in the open-circuit voltage Voc of the battery is measured and a stable open-circuit voltage of the battery is made to be Voc1.
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16. The detecting method according to claim 8 or 10, wherein for the inspective rechargeable battery which is in a paused state without subjecting to charging or discharging, after an open-circuit voltage Voc thereof is measured, charging for said rechargeable battery is started at a charging voltage Ic1 where a battery voltage Vc of the battery is measured, followed by charging an electricity quantity q1 of a time t1×
- a charge-and-discharge efficiency Eff where the charging operation is terminated when the battery voltage of the battery becomes Vc1, where an open-circuit voltage Voc1 of the battery after an elapse of a prescribed period of time is measured.
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17. The detecting method according to claim 15 or 16, wherein:
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(1) when the inspective rechargeable battery falls in any of the following cases (i) to (iii), the inspective battery is judged to be short-circuited;
(i) a case where with reference to the basic data mentioned in (1) of claim 8, a remaining capacity Q0 of the normal rechargeable battery when the open-circuit voltage of the normal rechargeable battery is Voc0 is estimated, and when a difference between an open-circuit voltage Voc(Q0+q1) of the normal rechargeable battery which is estimated with reference to the basic data mentioned in (1) of claim 8 and the open-circuit voltage Voc1 of the inspective rechargeable battery falls in a range of [Voc(Q0+q1)−
Voc1]>
g1(g1>
0),(ii) a case where a difference between a battery voltage Vc(Q0+q1, Ic1, T) of the normal rechargeable battery which is estimated with reference to the basic data mentioned in (4) of claim 8 and the battery voltage Vc1 of the inspective rechargeable battery falls in a range of [Vc(Q0+q1, Ic1, T)−
Vc1]>
j1(j1>
0), and(iii) a case where a difference between an internal resistance Rc(Voc0, Ic, T) of the normal rechargeable battery which is estimated with reference to the basic data mentioned in (5) of claim 8 and an internal resistance Rc1 of the inspective rechargeable battery which is obtained in accordance with the equation Rc1=(Vc1−
Voc1)/Ic1 falls in a range of [Rc1−
Rc(Voc1, Ic1, T)]<
z1(z1<
0);
(2) when the difference between the open-circuit voltage Voc(Q0+q1) of the normal rechargeable battery and the open-circuit voltage Voc1 of the inspective rechargeable in the above (1)-(i) falls in a range of g0≦
[Voc(Q0+q1)−
Voc1]≦
g1(g0<
0<
g1), the inspective rechargeable battery is judged that the electricity storable capacity is not decreased, then by assuming that transient characteristics of the battery voltage (Vc) of the inspective rechargeable battery at an initial stage when the charging operation for the battery is commenced can be expressed by the equationVc=V1−
(V1−
Voc0)×
e−
t/τ(with t being a charging time, V1 being a battery voltage of the battery when the charging time is extrapolated to infinity, and τ
being a time constant) and in accordance with the battery voltage Vc to a measured charging time t and in accordance with said equation, a time constant τ
when the charging operation is initiated at a charging current Ic1 from the open-circuit voltage Voc0 and a battery voltage V1 are computed, and a difference between an internal resistance Rc1 of the inspected rechargeable battery which is obtained in accordance with the equation V1=Voc0+Ic1×
Rc1 or Rc1=(V1−
Voc0)/Ic1 and an internal resistance Rc(Voc0, Ic1, T) or Rc(Q0, Ic1, T) of the normal rechargeable battery which is estimated with reference to the basic data mentioned in (5) of claim 8 is subjected to a judgment of the inspective rechargeable battery as will be described below;
(i) when said difference falls in a range of z1≦
[Rc1−
Rc(Q0, Ic1, T)]≦
z2(z1<
0<
z2) or a range of j1≦
[Vc1−
Vc(Q0+q1, Ic1, T)]≦
j2(j1<
0<
j2), the inspective rechargeable battery is judged to be normal,(ii) when said difference falls in a range of [Rc1−
Rc(Q0, Ic1, T)]>
z2(0<
z2) or a range of j2<
[Vc1−
Vc(Q0+q1, Ic, T)](0<
j2), the rechargeable battery is judged that the internal resistance is increased, and(iii) when said difference falls in a range of [Voc(Q0+q1)−
Voc1]<
g0(g0<
0), the rechargeable battery is judged that the electricity storable capacity is decreased,whereby a deteriorated state and a remaining capacity of the inspective rechargeable battery is capable of being detected.
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18. The detecting method according to claim 17, wherein in the judgment (2)-(ii) of claim 17, when the inspective rechargeable battery is judged that the internal resistance is increased, for the inspective rechargeable battery which is in a paused state, charging is performed at least two times, that is, an electricity quantity q1 of a current value Ic1×
- a time t1 is charged from the battery voltage Voc0, followed by charging an electricity quantity q2 of a current value Ic2×
a time t2 where a battery voltage Vc of the inspective rechargeable battery duration until the charging operation is terminated and an open-circuit voltage Voc2 of the inspective rechargeable battery after the termination of the charging operation are measured, then by assuming that transient characteristics of the battery voltage of the inspective rechargeable battery at a initial stage of the commencement of the charging operation can be expressed by an equation Vc=V2−
(V2−
Voc1)×
e−
t/τ
(with Vc being a battery voltage, t being a discharging time, V2 being a battery voltage of the battery when the discharging time t is extrapolated to infinity, and τ
being a time constant) and in accordance with the battery voltage V to a measured discharging time and in accordance with said equation, a time constant τ
when the charging operation is initiated at a discharging current Ic2 from the open-circuit voltage Voc1 and a battery voltage V2 are computed, then an internal resistance Rc2 of the inspective rechargeable battery at this time is computed from an equation V2=Voc1+Ic2×
Rc2 or Rc2=(V2−
Voc1)/Ic2, successively by assuming that the internal resistance of the inspective rechargeable battery is increased from the internal resistance Rc(Q, Ic, T) of the normal rechargeable battery to a×
Rc(Q, Ic, T)+b (where each of a and b is a constant) and in accordance with an equation Rc1−
[a×
Rc(Q0, Ic1, T)+b]=0 (where each of a and b is a constant) and an equation Rc2−
[a×
Rc(Q0+q1, Ic2, T)+b]=0 (where each of a and b is a constant) or an equation Rc2−
[a×
Rc(Q1, Ic2, T)+b]=0 (where each of a and b is a constant) using Q1=Q(Voc1), the constant a and the constant b are computed to estimate a value of the increased internal resistance Rc′
=a×
Rc(Q, Ic, T)+b, whereby a deteriorated state and a remaining capacity of the inspective rechargeable battery are capable of being detected.
- a time t1 is charged from the battery voltage Voc0, followed by charging an electricity quantity q2 of a current value Ic2×
-
19. The detecting method according to claim 17, wherein in the judgment (2)-(iii) of claim 17, when the inspective rechargeable battery is judged that the electricity storable capacity is decreased, by assuming that the electricity storable capacity C′
- of the inspective rechargeable battery is D time the electricity storable capacity C of the normal rechargeable battery (where D is a constant and is 0<
D<
1) and making the remaining capacity Q0′
of the inspective rechargeable battery to be Q0′
=Q0×
D (where Q0 is a remaining capacity of the normal rechargeable battery, and D is a constant and is 0<
D<
1) and with reference to the remaining capacity Q0 of the normal rechargeable battery which is corresponding to the open-circuit voltage Voc0 of the inspective rechargeable battery, the remaining capacity Q0′
=Q0×
D of the inspective rechargeable battery, the remaining capacity Q1 of the normal rechargeable battery which is corresponding to the open-circuit voltage Voc1 of the inspective rechargeable battery, and the remaining capacity Q1′
=Q0′
−
q1=Q1×
D of the inspective rechargeable battery and also with reference to function formulas Voc(Q0)=Voc(Q0′
/D)=Voc0 and Voc(Q1)=Voc(Q1′
/D)=Voc(Q0′
/D−
q1/D)=Voc1 which are obtained on the basis of the basic data mentioned in (1) of claim 8, a value of the constant D and a value of the remaining capacity Q1′
=Q0′
−
q1=Q1×
D are estimated, where judgment of the inspective rechargeable battery is performed as will be described below,(i) when a difference between the internal resistance Rc1 computed in the (2) of claim 17 and an internal resistance Rc(Q0′
/D, Ic1, T) estimated from the above basic data falls in a range of z1≦
[Rc1−
Rc(Q0′
/D, Ic1, T)]≦
z2(z1<
0<
z2), the inspective rechargeable battery is judged that the internal resistance is not increased but the electricity storable capacity is decreased, and(ii) when said difference falls in a range of [Rc1−
Rc(Q0′
/D, Ic1, T)]>
z2(0<
z2), the inspective rechargeable battery is judged that the internal resistance is increased and the electricity storable capacity is decreased;
then, for the inspective rechargeable battery, an electricity quantity q2 of a current value Ic2×
a time tc2 is charged from the open-circuit voltage Voc1, where a battery voltage of the inspective rechargeable battery duration until the charging operation is terminated and an open-circuit voltage Voc2 after the termination of the charging operation are measured, and by assuming that transient characteristics of the battery voltage of the inspective rechargeable battery at a initial stage of the commencement of the charging operation can be expressed by an equation Vc=V2−
(V2−
Voc1)×
e−
t/τ
(with Vc being a battery voltage, t being a charging time, V2 being a battery voltage of the battery when the charging time t is extrapolated to infinity, and τ
being a time constant), in accordance with the battery voltage Vc to a measured charging time t and in accordance with said equation, a time constant τ
when the charging operation is initiated at a charging current Ic2 from the open-circuit voltage Voc1 and a battery voltage V2 are computed, then an internal resistance Rc2 of the inspective rechargeable battery at this time is computed from an equation V2=Voc1+Ic2×
Rc2 or Rc2=(V2−
Voc1)/Ic2, successively by assuming that the internal resistance of the inspective rechargeable battery is increased from the internal resistance Rc(Q0′
/D, Ic, T) of the normal rechargeable battery to a×
Rc(Q0′
/D, Ic, T)+b (where each of a and b is a constant) and in accordance with an equation Rc1−
[a×
Rc(Q0′
/D, Ic1, T)+b]=0 (where each of a and b is a constant) and an equation Rc2−
[a×
Rc(Q0′
/D+q1/D, Ic2, T)+b]=0 or an equation Rc2−
[a×
Rd(Q1′
/D, Ic2, T)+b]=0 (where each of a and b is a constant) using Q1=Q1′
/D=Q(Voc1), the constant a and the constant b are computed to estimate a value of the increased internal resistance Rc′
=a×
Rc(Q′
/D, Ic, T)+b (where Q′
is a true remaining capacity when the electricity storable capacity is decreased) of the inspective rechargeable battery, whereby a deteriorated state and a remaining capacity of the inspective rechargeable are capable of being detected.
- of the inspective rechargeable battery is D time the electricity storable capacity C of the normal rechargeable battery (where D is a constant and is 0<
-
20. The detecting method according to claim 1 or 2, wherein the inspective rechargeable battery is subjected to charging and the charging operation is terminated at a battery voltage VcE, where a change with the passage of time in the open-circuit voltage Voc of the battery is detected.
-
21. The detecting method according to claim 1 or 2, wherein the inspective rechargeable battery is subjected to charging and the charging operation is terminated at a battery voltage VcE, where an open-circuit voltage VocE of the battery after an elapse of a prescribed period of time is detected.
-
22. The detecting method according to claim 20, wherein a time t since the termination of the charging operation and an open-circuit voltage Voc of the inspective rechargeable battery at that time are measured, by making an open-circuit voltage of the inspective rechargeable battery when the open-circuit voltage Voc becomes to be a steady state to be VocE and summing that the open-circuit voltage Voc can be expressed by an equation Voc=VocE+(VcE−
- VocE)×
e−
t/τ
(with Voc being an open-circuit voltage, t being a time, VocE being an open-circuit voltage when the time t is extrapolated to infinity, and τ
being a time constant), in accordance with this equation and from the Voc values measured at a plurality of time points, a time constant τ
is computed and a value of the VocE is estimated.
- VocE)×
-
23. The detecting method according to claim 20 or 21, wherein the inspective rechargeable battery is judged to be short-circuited when the inspective rechargeable battery falls in any of the following cases (i) and (ii);
-
(i) a case where a change with the passage of time in the open-circuit voltage Voc of the inspective rechargeable battery, namely, a decrease rate (−
dVoc/dt) of the open-circuit voltage is greater than that (ve) of the corresponding normal rechargeable battery, that is, −
dVocE/dt>
ve>
0, and(ii) a case where the charge termination voltage VcE of the inspective rechargeable battery is smaller than that (m0) of the corresponding normal rechargeable battery, that is, VcE<
m0(0<
m0).
-
-
24. The detecting method according to claim 1 or 2, wherein the inspective rechargeable battery is charged by a constant current-constant voltage charging method wherein the inspective rechargeable battery is charged at a prescribed constant current value until the battery voltage reaches a prescribed upper limit battery voltage VcL and following this constant current discharging operation, the inspective rechargeable battery whose battery voltage is VcL is charged at a constant voltage VcL and after an elapse of a prescribed period of time, the charging operation is terminated, where the inspective rechargeable battery is judged with respect to internal state while comparing with a normal rechargeable battery corresponding to the inspective rechargeable battery and having been charged by the constant current-constant voltage charging method as will be described below:
-
(1) when the inspective rechargeable battery falls in any of the following cases (i) to (iii), the inspective rechargeable battery is judged to be short-circuited;
(i) a case where a change (−
dVocE/dt) with the passage of time in the open-circuit voltage (VocE) of the inspective rechargeable battery after full-charging in the constant current-constant voltage charging operation is greater than that (ve) of the corresponding normal rechargeable battery, that is, −
dVocE/dt>
ve>
0,(ii) a case where the battery voltage (VcE) of the inspective rechargeable battery when the entire charging operation is terminated is smaller than that (m0) of the corresponding normal rechargeable battery, that is, VcE<
m0(0<
m0), and(iii) a case where an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery upon the constant current charging operation is smaller than that (s0) of the corresponding normal rechargeable battery, that is, dVc/dt<
s0(0<
s0);
(2) when an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery upon the constant current charging is greater than that (s1) the corresponding normal rechargeable battery, that is, dVc/dt>
s1>
0, and the open-circuit voltage (VocE) of the inspective rechargeable battery after full-charging in the constant current−
constant voltage charging operation is smaller than that (Vocn) of the corresponding normal rechargeable battery, that is, 0<
VocE<
Vocn, the inspective rechargeable battery is judged that the internal resistance is increased;
(3) when a period of time consumed to reach the upper limit voltage (VcL) from the prescribed battery voltage in the constant current charging operation for the inspective rechargeable batter is shorter than that for the corresponding normal rechargeable battery or an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery in the constant current charging is greater than that (s1) of the corresponding normal rechargeable battery, that is, dVc/dt>
s1>
0, and the open-circuit voltage (VocE) of the inspective rechargeable battery after full-charging in the constant current-constant voltage charging operation is greater than that (Vocn) of the corresponding normal rechargeable battery, that is, VocE≧
Vocn>
0, the inspective rechargeable battery is judged that the electricity storable capacity is decreased;
(4) when a period of time consumed to reach the upper limit voltage (VcL) from the prescribed battery voltage in the constant current charging for the inspective rechargeable batter is substantially the same as that for the corresponding normal rechargeable battery or an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery in the constant current charging operation is substantially the same as that (s1) of the corresponding normal rechargeable battery, that is, s0≦
dVc/dt≦
s1(0<
s0<
s1), and the open-circuit voltage (VocE) of the inspective rechargeable battery after full-charging in the constant current-constant voltage charging operation is substantially the same as or greater than that (Vocn) of the corresponding normal rechargeable battery, that is, 0<
Vocn≦
VocE, the inspective rechargeable battery is judged to be normal,whereby the internal state of the inspective rechargeable battery is capable of being detected.
-
-
25. The detecting method according claim 1 or 2, wherein when constant current charging for the inspective rechargeable battery is terminated by detecting a battery voltage thereof, a change with the passage of time in the battery voltage, a battery temperature of the battery or a change with the passage of time in the battery temperature,
(1) when the inspective rechargeable battery falls in any of the following cases (i) to (iii), the inspective rechargeable battery is judged to be short-circuited: -
(i) a case where a change (−
dVocE/dt) with the passage of time in the open-circuit voltage (VocE) of the inspective rechargeable battery after full-charging is greater than that (ve) of a normal rechargeable battery corresponding to the inspective rechargeable battery and having been subjected to the constant current charging in the same manner as the inspective rechargeable battery, that is, −
dVocE/dt>
ve>
0,(ii) a case where an increase rate (dT/dt) of the battery temperature (T) of the inspective rechargeable battery upon the constant current charging operation is greater than that (u0) of the corresponding normal rechargeable battery, that is, dT/dt>
u0>
0, and(iii) a case where an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery upon the constant current charging operation is smaller than that (s0) of the corresponding normal rechargeable battery, that is, 0<
dVc/dt<
s0;
(2) when an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery upon the constant current charging operation is greater than that (s1) of the corresponding normal rechargeable battery, that is, dVc/dt>
s1>
0, and an open-circuit voltage (VocE) of the inspective rechargeable battery after the termination of the constant current charging operation is smaller than that (Vocn) of the corresponding normal rechargeable battery, that is, 0<
VocE<
Vocn, the inspective rechargeable battery is judged that the internal resistance is increased;
(3) when an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery during the constant current charging operation is greater than that (s1) of the corresponding normal rechargeable battery, that is, dVc/dt>
s1>
0, and an open-circuit voltage (VocE) of the inspective rechargeable battery after the termination of the constant current charging operation is greater than that (Vocn) of the corresponding normal rechargeable battery, that is, VocE>
Vocn(0<
Vocn), the inspective rechargeable battery is judged that the electricity storable capacity is decreased;
(4) when an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery during the constant current charging operation is substantially the same as that (s1) of the corresponding normal rechargeable battery, that is, s0≦
dVc/dt≦
s1(0<
s0<
s1), and an open-circuit voltage (VocE) of the inspective rechargeable battery after the termination of the constant current charging operation is substantially the same as or greater than that (Vocn) of the corresponding normal rechargeable battery, that is, 0<
Vocn≦
VocE, the inspective rechargeable battery is judged to be normal;
whereby the internal state of the inspective rechargeable battery is capable of being detected.
-
-
26. The detecting method according to claim 1 or 2, wherein when constant current charging for the inspective rechargeable battery is terminated after an elapse of a prescribed period of time since the commencement of the constant current charging or when the battery voltage of the inspective rechargeable battery reaches a prescribed upper limit voltage (VcL),
(1) when the inspective rechargeable battery falls in any of the following cases (i) to (iii), the inspective rechargeable battery is judged to be short-circuited: -
(i) a case where a change (−
dVocE/dt) with the passage of time in the open-circuit voltage (VocE) of the inspective rechargeable battery after full-charging is greater than that (ve) of a normal rechargeable battery corresponding to the inspective rechargeable battery and having been subjected to the constant current charging in the same manner as the inspective rechargeable battery, that is, −
dVocE/dt>
ve>
0,(ii) a case where a battery voltage (VcE) of the inspective rechargeable battery upon the termination of the constant current charging operation is smaller than that (m0) of the corresponding normal rechargeable battery, that is, VcE<
m0(m0>
0), and(iii) a case where an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery upon the constant current charging operation is smaller than that (s0) of the corresponding normal rechargeable battery, that is, 0<
dVc/dt <
s0;
(2) when an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery during the constant current charging operation is greater than that (s1) of the corresponding normal rechargeable battery, that is, dVc/dt>
s1>
0, and an open-circuit voltage (VocE) of the inspective rechargeable battery after the termination of the constant current charging operation is smaller than that (Vocn) of the corresponding normal rechargeable battery, that is, 0<
VocE≦
Vocn, the inspective rechargeable battery is judged that the internal resistance is increased;
(3) when an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery during the constant current charging operation is greater than that (s1) of the corresponding normal rechargeable battery, that is, dVc/dt>
s1>
0, and an open-circuit voltage (VocE) of the inspective rechargeable battery after the termination of the constant current charging operation is greater than that (Vocn) of the corresponding normal rechargeable battery, that is, VocE>
Vocn (0<
Vocn), the inspective rechargeable battery is judged that the electricity storable capacity is decreased;
(4) when an increase rate (dVc/dt) of the battery voltage (Vc) of the inspective rechargeable battery during the constant current charging operation is substantially the same as that (s1) of the corresponding normal rechargeable battery, that is, s0≦
dVc/dt≦
s1(0<
s0<
s1), and an open-circuit voltage (VocE) of the inspective rechargeable battery after the termination of the constant current charging operation is substantially the same as or greater than that (Vocn) of the corresponding normal rechargeable battery, that is, 0<
Vocn≦
VocE, the inspective rechargeable battery is judged to be normal;
whereby the internal state of the inspective rechargeable battery is capable of being detected.
-
-
27. The detecting method according to claim 1 or 2, wherein when the inspective rechargeable battery is in a state that it is being subjected to discharging, the inspective rechargeable battery is judged to be in a last stage where a residual electricity quantity capable of being discharged is little or to be short-circuited when the battery voltage is less than a prescribed voltage value from the basic data of a normal rechargeable battery corresponding to the inspective rechargeable battery or when a decrease rate (−
- dVd/dt) of the battery voltage (Vd) is greater than a prescribed value (x1) from said basic data, that is, −
dVd/dt>
x1(0<
x1).
- dVd/dt) of the battery voltage (Vd) is greater than a prescribed value (x1) from said basic data, that is, −
-
28. The detecting method according to claim 1 or 2, wherein when the inspective rechargeable battery is in a state that it is being subjected to discharging, a discharging current (Id0) of the discharging operation and a battery voltage (Vd) of the inspective rechargeable battery are measured, where when the battery voltage (Vd) is greater than a prescribed voltage value the basic data of a normal rechargeable battery corresponding to the inspective rechargeable battery or when a decrease rate (−
- dVd/dt) of the battery voltage (Vd) is less than a prescribed value (x1) from said basic data, that is, 0<
−
dVd/dt x1, the inspective rechargeable battery is judged to be normal or to be in a deterioration mode other than short-circuit.
- dVd/dt) of the battery voltage (Vd) is less than a prescribed value (x1) from said basic data, that is, 0<
-
29. The detecting method according to claim 28, wherein when the inspective rechargeable battery is in a substantially steady state while being subjected to discharging where a discharging current of the discharging operation is Id0, a battery temperature of the inspective rechargeable battery is T and a battery voltage of the inspective rechargeable battery is Vd0 where a remaining capacity of the battery is Q0 and after an electricity quantity q is discharged, the battery voltage of the inspective rechargeable battery in the steady state becomes to be Vd1 at a discharging current Id1, with reference to the basic data mentioned in (1) and (2) of claim 8, a battery voltage Vd0=Vd(Q0, Id0, T) and a remaining capacity Q0=Q(Vd0, Id0, T) of the normal rechargeable battery when the battery voltage is Vd0 are estimated and a battery voltage Vd(Q0−
- q, Id1, T) when the remaining capacity becomes (Q0−
q) from Q0 and a remaining capacity Q(Vd1, Id1, T) of the normal rechargeable battery when the battery current is Id1 and the battery voltage is Vd1 are estimated, and the inspective rechargeable battery is subjected to a judgment as will be described below;
(1) (i) when y1≦
[Vd1−
Vd(Q0−
q, Id1, T)]≦
y2(y1<
0y2) or (ii) when w1Q(Vd1, Id1, T)−
[Vd0, Q(Id0, T)−
q]≦
w2(w1<
0<
w2), the inspective rechargeable battery is judged to be normal;
(2) (i) when [Vd1−
Vd(Q0−
q, Id1, T)]>
y2 (0<
y2) or (ii) when Q(Vd1, Id1, T)−
[Q(Vd0, Id0, T)−
q]>
w2 (0<
w2), the inspective rechargeable battery is judged that the internal resistance is increased; and
(3) (i) when [Vd1−
Vd(Q0−
q, Id1, T)]<
y1(y1<
0) or (ii) when Q(Id1, Vd1, T)−
[Q(Id0, Vd0, T)−
q]<
w1(w1<
0), the inspective rechargeable battery is judged that the electricity storable capacity is decreased;
whereby the internal state of the inspective rechargeable battery is capable of being detected.
- q, Id1, T) when the remaining capacity becomes (Q0−
-
30. The detecting method according to claim 29, wherein for the inspective rechargeable battery in the substantially steady state where the discharging current is a steady discharging current of Ino and the battery voltage is Vno, when the discharging current is changed n-times (with n being a positive integer of 1, 2, 3, 4, . . . ) such that the discharging current is changed to In1 from Ino and an electricity quantity qn of a current value In1×
- a time tn1 is discharged and thereafter, the discharging current is returned to the steady discharging current Ino, battery voltages (V) at a plurality of time points upon changes in the discharging current are measured and by assuming that transient characteristics of the battery voltage (V) when the discharging current is changed can be expressed by an equation V=Vn1+(Vno−
Vn1)×
e−
t/τ
(with t being a discharging time, Vn1 being a battery voltage of the battery when the discharging time t is extrapolated to infinity, τ
being a time constant, and n is a positive integer of 1, 2, 3, 4, . . . ), and in accordance with the measured battery voltages V to the time t since the time when the discharging current is changed and in accordance with said equation, the time constant τ
is estimated and a true value of the Vn1 is estimated, whereby the internal state of the rechargeable battery is detected.
- a time tn1 is discharged and thereafter, the discharging current is returned to the steady discharging current Ino, battery voltages (V) at a plurality of time points upon changes in the discharging current are measured and by assuming that transient characteristics of the battery voltage (V) when the discharging current is changed can be expressed by an equation V=Vn1+(Vno−
-
31. The detecting method according to claim 30, wherein in a case where the discharging current for the inspective rechargeable battery is changed at least three times such that when the battery voltage in the steady discharging at a discharging current I10 is V10, the discharging current is changed to I11 and an electricity quantity q1 of a current value I11×
- a time t11 from the battery voltage V10 is discharged where the battery voltage is changed to V20 from V10, then, the discharging current I20 of the steady discharging is changed to I21 and an electricity quantity q2 of a current value I21×
a time t21 is discharged from the battery voltage V20 where the battery voltage is changed to V30 from V20, and the discharging current I30 of the steady discharging is changed to I31 and an electricity quantity q3 of a current value I31×
a time t31 is discharged from the battery voltage V30 where the battery voltage is changed to V40 from V30, wherein as a result that the discharging current In0 of the steady discharging is changed to In1 and an electricity quantity qn of a current value In1×
a time n1 is discharged, when the inspective rechargeable battery is judged that the internal resistance is increased in (2) of claim 29,then, by assuming that the internal resistance of the inspective rechargeable battery is changed from the internal resistance Rd(Q, Id, T) of the corresponding normal rechargeable battery to an internal resistance Rd′
(Q, Id, T)=a×
Rd(Q, Id, T)+b (where each of a and b is a constant) and also assuming that transient characteristics of the battery voltage in every change in the discharging current can be expressed by an equation V=Vn1+(Vno−
Vn1)×
et/τ
(with t being a discharging time, Vn1 being a battery voltage of the battery when the discharging time t is extrapolated to infinity, τ
being a time constant, and n is a positive integer of 1, 2, 3, 4, . . . ), in accordance with the measured battery voltages V to the time t since the time when the discharging current is changed and in accordance with said equation, the time constant τ
when the discharging current In0 is changed to In1 is estimated and a true value of the Vn1 is estimated,further, an open-circuit voltage Vocn0 of the inspective rechargeable battery having a remaining capacity Qno when the discharging current is Ino and the battery voltage is expressed to be Vocn0=Vn0+In0×
Rd′
(Qn0, In0, T)=Vn1+In1×
Rd′
(Qn0, In1, T)[where n=1, 2, 3, . . . ],and when the remaining capacities when battery voltages are V10, V20, and V30 are made to be Q10, Q20, and Q30, the following relationships are established; Q20=Q10−
q1Q30=Q20−
q2=Q1031 q1−
q2V10−
V11=I11×
Rd′
(Q10, I11, T)−
I10×
Rd′
(Q10, I10, T)V20−
V21=I21×
Rd′
(Q20, I21, T)−
I20×
Rd′
(Q20, I20, T)V30−
V31=I31×
Rd′
(Q30, I31, T)−
I30×
Rd′
(Q30, I30, T)Rd′
(Q10, I10, T)=a×
Rd(Q10, I10, T)+bRd′
(Q10, I11, T)=a×
Rd(Q10, I11, T)+bRd′
(Q20, I20, T)=a×
Rd(Q20, I20, T)+bRd′
(Q20, I21, T)=a×
Rd(Q20, I21, T)+bRd′
(Q30, I30, T)=a×
Rd(Q30, I30, T)+bRd′
(Q30, I31, T)=a×
Rd(Q30, I31, T)+b(where each of a and b is a constant) by solving these equations, the constants a and b and the remaining capacity Q10 are estimated and a present remaining capacity Q30 and an internal resistance Rd′
(Q, I, T) of the inspective rechargeable battery which is deteriorated to increase the internal resistance are estimated, whereby the internal state of the inspective rechargeable battery is detected.
- a time t11 from the battery voltage V10 is discharged where the battery voltage is changed to V20 from V10, then, the discharging current I20 of the steady discharging is changed to I21 and an electricity quantity q2 of a current value I21×
-
32. The detecting method according to claim 30, wherein in a case where the discharging current when the battery temperature is is changed at least four times from the steady discharging state such that when the battery voltage in the steady discharging at a discharging current I10 is V10, the discharging current is changed to I11 and an electricity quantity q1 of a current value I11×
- a time t11 from the battery voltage V10 is discharged where the battery voltage is changed to V20 from V10, then the discharging current I20 of the steady discharging is changed to I21 and an electricity quantity q2 of a current value I21×
a time t21 is discharged from the battery voltage V20 where the battery voltage is changed to V30 from V20, successively the discharging current I30 of the steady discharging is changed to I31 and an electricity quantity q3 of a current value I31×
a time t31 is discharged from the battery voltage V30 where the battery voltage is changed to V40 from V30, finally the discharging current I40 of the steady discharging is changed to I41 and an electricity quantity q4 of a current value I41×
a time t41 is discharged from the battery voltage V40 where the battery voltage is changed to V50 from V40, wherein as a result that the discharging current In0 of the steady discharging is changed to In1 and an electricity quantity qn of a current value In1×
a time n1 is discharged, when the inspective rechargeable battery is judged that the electricity storable capacity is decreased in (3) of claim 29,then, the electricity storable capacity of the inspective rechargeable battery is assumed to be decreased from C to C′
=D×
C (where D is a constant of 0<
D<
1), the remaining capacity of the inspective rechargeable battery is assumed to be decreased from the remaining capacity Q of the corresponding normal rechargeable to a remaining capacity Q′
=D×
Q, and the internal resistance of the inspective rechargeable battery is assumed to be increased from the internal resistance Rd(Q, Id, T) of the corresponding normal rechargeable battery to an internal resistance R′
(Q, Id, T)=a×
Rd(Q, Id, T)+b (where each of a and b is a constant),successively, it is assumed that transient characteristics of the battery voltage in every change in the discharging current can be expressed by an equation V−
Vn1+(Vn0−
Vn1)×
e−
t/τ
(with t being a discharging time, Vn1 being a battery voltage of the battery when the discharging time t is extrapolated to infinity, τ
being a time constant, and n is a positive integer of 1, 2, 3, 4, . . . ),in accordance with the measured battery voltages V to the time t since the time when the discharging current is changed and in accordance with said equation, the time constant τ
when the discharging current In0 is changed to In1 is estimated and a true value of the Vn1 is estimated, next, an open-circuit voltage Vocn0 of the inspective rechargeable battery having a remaining capacity Qn0 when the discharging current is In0 and the battery voltage is Vn0 is expressed to be Vocn0=Vn0+In0×
Rd′
(Qn0, In0, T)=Vn1+In1×
Rd′
(Qn0, In1, T)[where n=1, 2, 3, . . . ],and when the remaining capacities when battery voltages are V10, V20, V30, and V40 are made to be Q10, Q20, Q30 and Q40, the following relationships are established;
when Q=Q′
/;
DQ20′
=Q10′
−
q1Q30′
=Q20′
−
q2=Q10′
−
q1−
q2Q40′
=Q30−
q3=Q10′
−
q1−
q2q3when Q10=Q10′
/D, Q20=(Q10′
−
q1)/D, Q30=(Q10′
−
q1−
q2)/D,and Q40=(Q10′
−
q1−
q2q3)/D;
V10−
V11=I11×
Rd′
(Q10, I11, T)−
I10×
Rd′
(Q10, I10, T)V20−
V21=I21×
Rd′
(Q20, I21, T)−
I20×
Rd′
(Q20, I20, T)V30−
V31=I31×
Rd′
(Q30, I31, T)−
I30×
Rd′
(Q30, I30, T)V40−
V41=I41×
Rd′
(Q40, I41, T)−
I40×
Rd′
(Q40, I40, T)Rd′
(Q10, I10, T)=a×
Rd(Q10, I10, T)+bRd′
(Q10, I11, T)=a×
Rd(Q10, I11, T)+bRd′
(Q20, I20, T)=a×
Rd(Q20, I20, T)+bRd′
(Q20, I21, T)=a×
Rd(Q20, I21, T)+bRd′
(Q30, I30, T)=a×
Rd(Q30, I30, T)+bRd′
(Q30, I31, T)=a×
Rd(Q30, I31, T)+bRd′
(Q40, I40, T)=a×
Rd(Q40, I40, T)+bRd′
(Q40, I41, T)=a×
Rd(Q40, I41, T)+b(where each of a and b is a constant) By solving these equations, a value of each of the constants a and b, a value of the D, and a value of the Q10=Q10′
/D are estimated, and a value of the electricity storable capacity which is deteriorated to be D time and a value of the increased internal resistance are estimated, whereby the internal state of the inspective rechargeable battery is detected.
- a time t11 from the battery voltage V10 is discharged where the battery voltage is changed to V20 from V10, then the discharging current I20 of the steady discharging is changed to I21 and an electricity quantity q2 of a current value I21×
-
33. The detecting method according to any of claims 30 to 32, wherein a current of Δ
- Id is intentionally flown so that the discharging current In1 becomes to be In1=In0+Δ
Id which is greater than the steady discharging current In0.
- Id is intentionally flown so that the discharging current In1 becomes to be In1=In0+Δ
-
34. The detecting method according to claim 33, wherein the discharging current In1 is less than a current value of 2C.
-
35. The detecting method according to any of claims 12, 17, 24, 25, 26, and 29, wherein for the inspective rechargeable battery judged to be normal, the internal state thereof is detected as will be described below:
-
(1) when the inspective rechargeable battery is in a paused state, using data or function formula of the relationship Voc(Q0)=Voc0 or Q0=Q(Voc0) derived from the open-circuit voltage (Voc0) of the inspective rechargeable battery and the basic data mentioned in (1) of claim 8, a remaining capacity Q0 of the inspective rechargeable battery is estimated;
(2) when the inspective rechargeable battery is during it being subjected to charging, a remaining capacity of the inspective rechargeable battery is estimated by any of the following manners (i) to (iii);
(i) by measuring a charging current for the inspective rechargeable battery during the charging operation, a battery temperature and a battery voltage of the inspective rechargeable battery and with reference to the basic data and the function formula Vc(Q, Ic, T) or Q (Vc, Ic, T) mentioned in (4) of claim 8, a remaining capacity of the inspective rechargeable battery is estimated, (ii) the charging operation is temporarily suspended, where a charging time τ and
an open-circuit voltage Voc of the inspective rechargeable battery are measured to estimate a remaining capacity of the inspective rechargeable battery at that time, and(iii) by measuring a charging termination voltage VcE of the inspective rechargeable battery and an open-circuit voltage VocE of inspective rechargeable battery after the termination of the charging operation and with reference to data or function formulas of a relationship VcE(QE, Ic, T) or Q(VcE, Ic, T) derived from the basic data or the function formulas mentioned in (4) of claim 8 or data or function formulas of a relationship Voc(QE)=VocE or QE=Q(VocE) derived from the basic data or function formulas mentioned in (1) of claim 8, a remaining capacity of the inspective rechargeable battery is estimated;
(3) when the inspective rechargeable battery is during it being subjected to discharging, a remaining capacity of the inspective rechargeable battery is estimated by any of the following manners (i) to (ii);
(i) with reference to the function formula Vd(Q, Id, T) or Q(Vd, Id, T) mentioned in (2) of claim 8, a remaining capacity of the inspective rechargeable battery is estimated, and (ii) by estimating an internal resistance Rd of the inspective rechargeable battery and with reference to the function formula Q(Rd, Id, T) mentioned in (3) of claim 8, a remaining capacity the inspective rechargeable battery is estimated.
-
-
36. The detecting method according to claim 18, wherein for the inspective rechargeable battery judged to free of short-circuit and of a decrease in the electricity storable but have an increase in the internal resistance, an increased internal resistance Rc′
- (Q, Ic, T) upon the charging operation is estimated and with reference to a relation expression Vc=Voc(Q)+Ic×
Rc′
(Q, Ic, T) of a relationship between the battery voltage, the open-circuit voltage Voc(Q), the charging current Ic, and the internal resistance Rc′
(Q, Ic, T) upon the charging operation, a electricity storable capacity C′
of the inspective rechargeable battery upon the termination of the charging operation is estimated from measured values of the charging current, battery voltage and open-circuit voltage upon the termination of the charging operation.
- (Q, Ic, T) upon the charging operation is estimated and with reference to a relation expression Vc=Voc(Q)+Ic×
-
37. The detecting method according to claim 13 or 31, wherein for the inspective rechargeable battery judged to free of short-circuit and of a decrease in the electricity storable but have an increase in the internal resistance, an increased internal resistance Rd′
- (Q, Id, T) of the inspective rechargeable battery upon the discharging operation is estimated, and with reference to a relation expression Vd=Voc(Q)−
Id×
Rd′
(Q, Id, T) of said increased internal resistance [in said relation expression, Vd is abatteryvoltage, Voc(Q) is an open-circuit voltage, Q is a remaining capacity, Id is a discharging current, and Rd′
(Q, Id, T) is said internal resistance] and also reference to a function formula Vd=Vd(Q, Id, T) [where T is a battery temperature], a battery voltage (Vd), a discharging current (Id), and a battery temperature (T) of the inspective rechargeable battery are measured upon the discharging operation, and a remaining capacity (Q) of the inspective rechargeable battery is computed.
- (Q, Id, T) of the inspective rechargeable battery upon the discharging operation is estimated, and with reference to a relation expression Vd=Voc(Q)−
-
38. The detecting method according to claim 19, wherein for the inspective rechargeable battery judged that the electricity storable capacity is decreased, a decrease coefficient D (0<
- D<
1) of the decreased electricity storable capacity is estimated, and(1) when the internal resistance of the inspective rechargeable battery is not decreased, the electricity storable capacity is estimated to be D time the nominal capacity of the corresponding normal rechargeable battery, and (2) when the internal resistance is increased, with reference to a relation expression Vc=Voc(Q)+Ic×
Rc′
(Q, Ic, T) [where Vc is a battery voltage, Voc is an open-circuit voltage, Q is a remaining capacity, Ic is a charging current, and Rc′
(Q, Id, T) is said increased internal resistance], a remaining capacity (Q) of the inspective rechargeable battery is computed and the value of the computed Q upon termination of full-charging is multiplied by D where the value obtained is estimated as an electricity storable capacity C′
upon the termination of the full-charging.
- D<
-
39. The detecting method according to claim 14 or 32, wherein the inspective rechargeable battery is judged that the electricity storable capacity is decreased, and
(1) when the internal resistance of the inspective rechargeable battery is not decreased, a decrease coefficient D (0< - D<
1) of the decreased electricity storable capacity is estimated, and the electricity storable capacity of the inspective rechargeable battery is estimated to be D time the nominal capacity of the corresponding normal rechargeable battery, and(2) when the internal resistance is increased, the decrease coefficient of the decreased electricity storable capacity and the increased internal resistance upon the discharging operation are estimated as a function formula Rd′
(Q, Id, T), and with reference to a relation expression Vd=Voc(Q)−
Id×
Rd′
(Q, Ic, T) [where Vc is a battery voltage, Voc(Q) is an open-circuit voltage, Q is a remaining capacity, Ic is a charging current, and Rc′
(Q, Id, T) is said increased internal resistance]and also reference to a function formula Vd=Vd(Q, Id, T) [where T is a battery temperature], a battery voltage (Vd), a discharging current (Id), and a battery temperature (T) of the inspective rechargeable battery are measured upon the discharging operation to estimate an apparent remaining capacity (Q) of the inspective rechargeable battery, and the apparent remaining capacity (Q) is multiplied by D to obtain a remaining capacity Q′
=D×
Q as a true remaining capacity of the inspective rechargeable battery.
- D<
-
40. The detecting method according to any of claims 35, 36 and 38, wherein for the inspective rechargeable battery is during it being subjected to charging, a remaining capacity Q thereof is computed and a period of time until reaching a remaining capacity upon the termination of the charging operation is computed.
-
41. The detecting method according to any of claims 35, 37, and 39, wherein for the inspective rechargeable battery is during it being subjected to discharging, after a remaining capacity Q thereof is computed and a remaining capacity Qmin of the inspective rechargeable battery when the battery voltage becomes to be a minimum actuation voltage Vmin of an instrument in which the inspective rechargeable battery is used as the power source is computed, an usable capacity (Q−
- Qmin) of the inspective rechargeable battery with which the instrument is still able to operate is computed.
-
42. The detecting method according to claim 41, wherein after the usable capacity (Q−
- Qmin) of the inspective rechargeable battery is computed, in accordance with an equation h=(Q−
Qmin)/i (where h is an actuation time of the instrument, and i is an average consumptive current of the instrument) or h=(Vd+Vmin)×
(Q−
Qmin)/2p (where p is an average consumptive power), a residual actuation time of the instrument is computed.
- Qmin) of the inspective rechargeable battery is computed, in accordance with an equation h=(Q−
-
43. The detecting method according to claim 8, wherein the temperature T is a temperature in a range of −
- 30°
C. to +80°
C.
- 30°
-
44. The detecting method according to claim 8, wherein the temperature T is a temperature in a range of −
- 20°
C. to +60°
C.
- 20°
-
45. The detecting method according to claim 11, wherein the discharging current is a rectangular wave pulse current.
-
46. The detecting method according to claim 15 or 16, wherein the discharging current is a rectangular wave pulse current.
-
47. The detecting method according to claim 33, wherein the discharging current is a rectangular wave pulse current.
-
48. The detecting method according to claim 33, wherein the changing discharging current comprises a pausing pulse with no discharging current.
-
49. The detecting method according to claim 42, wherein the value of the average consumptive current or that of the average consumptive power is a value computed based on an operation pattern and a use frequency of the instrument by a user.
-
50. The detecting method according to claim 36 or 38, wherein when the acquired remaining capacity of the inspective rechargeable battery upon the termination of the charging operation is made to be C′
- and the nominal capacity of or the remaining capacity of the inspective rechargeable battery at a initial use stage is made to be C, the performance of the inspective rechargeable battery after having deteriorated is computed as a value of C′
/C or 100×
C′
/C [%].
- and the nominal capacity of or the remaining capacity of the inspective rechargeable battery at a initial use stage is made to be C, the performance of the inspective rechargeable battery after having deteriorated is computed as a value of C′
-
51. The detecting method according to claim 36 or 50, wherein when the performance 100×
- C′
/C [%] relating to the remaining capacity of the inspective rechargeable battery after having deteriorated becomes to be less than 60%, the inspective rechargeable battery is judged to be over the lifetime.
- C′
-
52. The detecting method according to any of claims 1 to 51, wherein the inspective rechargeable battery is a rechargeable battery in which oxidation-reduction reaction of lithium is used.
-
53. The detecting method according to any of claims 1 to 51, wherein the inspective rechargeable battery is a rechargeable battery in which a hydrogen storage alloy is used in the anode of the battery.
-
54. The detecting method according to any of claims 1 to 51, wherein the inspective rechargeable battery is a rechargeable battery in which a nickel hydroxide is used in the cathode.
-
55. The detecting method according to any of claims 1 to 51, wherein the inspective rechargeable battery is a nickel-cadmium rechargeable battery.
-
56. The detecting method according to any of claims 1 to 51, wherein the inspective rechargeable battery is a lead-acid rechargeable battery.
-
57. A detecting device for detecting an internal state of a rechargeable battery in which the detecting method defined in any of claims 1 to 51 is adopted.
-
58. The detecting device according to claim 57, comprising at least (i) a voltage-detecting means for detecting a voltage between a pair of terminals of an inspective rechargeable battery, (ii) a current-detecting means for detecting a charging or discharging current flown in said inspective rechargeable battery, (iii) a temperature-detecting means for detecting a temperature of said inspective rechargeable battery, and (iv) a memorizing means for memorizing previously acquired basic data of a normal rechargeable battery which is the same kind and the same type of said inspective rechargeable battery or a function formula obtained by digitizing said basic data, wherein from said basic data or said function formula memorized in said memorizing means (iv) and information obtained from said voltage-detecting means (i), said current-detecting means (ii) and said temperature-detecting means (iii), an internal state of said inspective rechargeable battery is detected.
-
59. The detecting device according to claim 58 which further comprises a current-changing means for intentionally changing a current flown in the inspective rechargeable battery.
-
60. The detecting device according to claim 59, wherein the current-changing means includes a means for adding a prescribed pulse current to the current flown in the inspective rechargeable battery.
-
61. The detecting device according to claim 58 which further comprises a current flow change-detecting means for detecting a change in the current flown in inspective rechargeable battery.
-
62. The detecting device according to claim 58 which further comprises a wave form-processing means for processing a signal wave form outputted from each of the voltage-detecting means (i), the current-detecting means (ii) and the temperature-detecting means (iii).
-
63. The detecting device according to claim 58 which further comprises a operational means for processing the basic data and the information obtained from each of the voltage-detecting means (i), the current-detecting means (ii) and the temperature-detecting means (iii).
-
64. The detecting device according to claim 63, wherein the operational means has one or more means selected from the group consisting of (1) a computation means for computing at least either a remaining capacity or an internal resistance of the inspective rechargeable battery, (2) a computation means for computing an usable capacity of the inspective rechargeable battery with which an instrument can be used and at least either an average consumptive current or an average consumptive power which is consumed by said instrument, and (3) a computation means for computing at least either a time required until charging operation for the inspective rechargeable battery is terminated or a remaining capacity of the inspective rechargeable battery after said charging operation is terminated.
-
65. The detecting device according to claim 58 which further comprises a judging means for judging whether the inspective rechargeable battery is normal or deteriorated and also judging a deterioration mode when the inspective rechargeable battery is deteriorated.
-
66. The detecting device according to claim 58 which further comprises a means for outputting at least either the information obtained from each of the voltage-detecting means (i), the current-detecting means (ii) and the temperature-detecting means (iii) or information relating to the internal state of the inspective rechargeable battery.
-
67. The detecting device according to claim 66 which includes an indication means for indicating at least either the information obtained from each of the voltage-detecting means (i), the current-detecting means (ii) and the temperature-detecting means (iii) or the information relating to the internal state of the inspective rechargeable battery.
-
68. A battery module comprising at least one rechargeable battery and which is provided with a detecting device defined in any of claims 57 to 67.
-
69. The battery module according to claim 68 which has a communication means to an instrument.
-
70. An instrument which is provided with a detecting device defined in any of claims 57 to 67.
-
71. The instrument according to claim 70 which has a communication means.
-
72. A machine which is provided with a detecting device defined in any of claims 57 to 67.
-
73. The instrument according to claim 71, wherein said instrument is a cellular phone or a personal digital assistant.
-
74. The instrument according to claim 70, wherein said instrument is a computer.
-
75. The machine according to claim 72, wherein said machine is a computer.
-
76. The machine according to claim 72, wherein said machine is a vehicle.
-
77. The machine according to claim 72, wherein said vehicle is a machine having wheels.
-
78. The instrument according to claim 70, wherein said instrument is a charger to charge a rechargeable battery.
-
79. The machine according to claim 72 which has a charger to charge a rechargeable battery.
-
80. The instrument according to claim 70, wherein said instrument is an instrument for inspecting a rechargeable battery product whether it is good or not good.
-
81. The machine according to claim 72, wherein said machine is a machine for inspecting a rechargeable battery product whether it is good or not good.
-
82. A power storage system having a detecting device defined in any of claims 57 to 67.
-
83. A detecting program for detecting an internal state of a rechargeable battery, having a detecting method defined in any of claims 1 to 56 installed therein.
-
84. A memory medium having a detecting program defined in claim 83 therein.
-
85. The detecting method according to claim 1 or 2, wherein two or more of the judgment items (i) to (v) are used in combination.
-
3. The detecting method according to claim 1 or 2, wherein said basic data (BD) are averaged basic data obtained by subjecting said normal non-deteriorated rechargeable battery (Bn) to charging and discharging under various temperature conditions and at various rates of charge or discharge where the battery voltages, and the remaining capacities or the discharged electricity quantities of the normal rechargeable battery (Bn) are measured and averaging the measured battery voltages and the measured remaining capacities or the measured discharged electricity quantities of the normal rechargeable battery (Bn).
-
-
2. A detecting method for detecting an internal state of an inspective rechargeable battery (Ba), said internal state including a deterioration state, an electricity storable capacity, a remaining capacity and an internal resistance of said inspective rechargeable battery (Ba),
said detecting method comprising: -
(1) a step in which basic data (BD) of characteristics of a normal non-deteriorated rechargeable battery (Bn) as a reference rechargeable battery for said inspective rechargeable battery (Ba) are provided; and
(2) a step in which for said inspective rechargeable battery (Ba), a voltage value or/and a current value thereof are measured, and the measured result is compared with said basic data (BD) obtained in said step (1) to judge;
(i) the inspective rechargeable battery (Ba) is short-circuited, (ii) the internal resistance of the inspective rechargeable battery (Ba) is increased, (iii) the electricity storable capacity of the inspective rechargeable battery (Ba) is decreased, (iv) the electricity storable capacity of the rechargeable battery (Ba) is decreased and the internal resistance thereof is increased, or (v) the inspective rechargeable battery (Ba) is normal, after this judgment, a remaining capacity of the inspective rechargeable battery (Ba) or a usable capacity thereof with which an instrument can be operated is computed.
-
Specification
- Resources
-
Current AssigneeCanon Kabushiki Kaisha (Canon Inc.)
-
Original AssigneeCanon Kabushiki Kaisha (Canon Inc.)
-
InventorsKawakami, Soichiro, Degura, Yasusaburo
-
Granted Patent
-
Time in Patent OfficeDays
-
Field of Search
-
US Class Current324/522
-
CPC Class CodesG01R 31/389 Measuring internal impedanc...G01R 31/392 Determining battery ageing ...G01R 31/52 Testing for short-circuits,...