DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Specification
The disclosure is objected to because of the following informalities:
The “charge rate” which is mentioned in the abstract and in the specification (¶[3, 4, 6, 15, 25, 29, 32-35, 37, 44]) of the claimed invention refers to the amount of charge or state of charge (SOC). But it can be confused with C-Rate or the rate of charge flow i.e. current or amperage. It is suggested to amend the term “charge rate” to “charge amount or SOC”.
Appropriate correction is required.
Claim Objections
Claim 1 and 2 are objected to because of the following informalities:
Claim 1 recites “at a time of full charge” in line 13. It is not sufficiently clear whose full charge (first cell or second cell or both or the battery itself) are being considered when performing the equalization process. Moreover, since SOC is below the lower limit of the flat region, the equalization would likely occur before the time of full charge operation. But in the claim, the equalization process takes place at the time of full charge.
Claim 1 further recites “charge rate”. It is unclear whether the charge rate refers to the capacity rate or C-rate, charging current or State of Charge (SOC) or another parameter. The examiner is interpreting the charge rate as the State of Charge of the battery cells after reading the specs of the claimed invention.
Claim 2 recites “the absolute value of the difference between the full charge capacity of the first cell and the full charge capacity of the second cell is less than the first threshold” in line 17-18. The specification in ¶[6] teaches of the “absolute value of the difference between the voltage of the first cell and the voltage of the second cell is equal to or greater than a third threshold”. The specification also teaches in ¶[44] “the voltage difference ΔV between the first cell and the second cell is equal to or greater than the third threshold value”. In Fig. 3 – S307, the voltage difference ΔV is taught to be equal to or greater than the third threshold value.
The voltage difference being equal to or greater than the third threshold value in order to perform the equalization process is not mentioned in the claim.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim 1 and 2 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated over Murao (U.S US 20090085520).
Independent Claim 1, Murao teaches the following:
An equalization control device (Fig. 1 – 2) for equalizing a plurality of battery cells (Fig. 1 – load 1) for a battery (abstract, ¶[15] discloses a state of charge optimizing device {being interpreted as equalization control device} … optimizing the state of charge of each of a plurality of cells … to form an assembled battery… to equalize the battery by discharging or charging each of the cells in accordance with the set equalization target value.)
in which an open circuit voltage is equal to or lower than a predetermined value (¶[53] mentions lithium ion battery cells which inherently possesses features such as a SOC-OCV characteristic curve with a flat area; Fig. 2, 3 and 7 shows the voltage being lower some predetermined threshold; ¶’s[54-55] discloses that the state of charge optimizing device having a voltage measuring circuit for each cell and a control circuit which controls discharge based on calculated optimization target voltage values {being interpreted as the open circuit voltage being within the voltage range});
the equalization control device comprising:
an acquisition unit for acquiring values of full charge capacities and voltages of a first cell and a second cell included in the battery cells (Fig. 1 – voltage measuring circuit 22; ¶[54] explicitly discloses a voltage measuring circuit 22 which measures the voltage across each cell {open-circuit voltage} and provides the measured value to control circuit 20 ¶[55]; ¶[63, 84-85] discloses of using the full charge capacity values, Q[i] and SOC[i] of i corresponding cells to acquire the current charge amount of each cell, thereby requiring the full-charge capacity and voltage values of the respective cells.) Although Murao doesn’t explicitly mention acquiring full charge capacity of each cell, the calculation process necessarily includes obtaining and storing the individual full charge capacities beforehand;
and a control unit for controlling equalization of the battery cells based on the values acquired by the acquisition unit (Fig. 1 – control circuit 20, ¶[55] teaches that control circuit calculates optimization target voltage values based on the measured values, and then controls discharging of each of the discharge circuits based on the calculated optimization target voltage values and the values measured by the respective voltage measuring circuits. Fig. 4 – S1-S3; ¶[58] teaches of the procedure of the optimizing process {being interpreted as controlling equalization of the battery cells} conducted by the control circuit. The control circuit measures the open-circuit voltage of each of the cells. It determines whether or not it is necessary to conduct the optimizing process.)
when a value of a difference between a full charge capacity of the first cell and a full charge capacity of the second cell is equal to or greater than a first threshold (s2 of Fig. 4 leads to Fig. 5, Fig. 8 – s37; ¶’s[57, 81, 82, 89, 90 esp. 89, 90] discloses that the cell optimizing/equalizing process is carried out when the difference between the full charge capacities of the respective cells, i and the cell with the smallest full charge capacity, j, i.e. Q[i] – Q[j] is greater than the upper limit {interpreted as the first threshold}),
the control unit performs equalization such that the value of a difference between a charge rate of the first cell and a charge rate (see claim objection interpretation) of the second cell at a time of full charge is less than a second threshold (all charging to 100% [i.e. full charge SOC [%] is less than a threshold SOC] as shown in at least Figs. [2, 3, 7]. ¶[80] mentions that the maximum charging capacity is obtained when the SOC of the cell with the smallest full charging capacity reaches 100 percent first {being interpreted as at a time of full charge}. ¶[15-17, esp. 16] mentions that based on the different full charge capacities, the equalization target value is “set to the amount of charge, or a value corresponding thereto, such that the difference between the amount of charge after optimization and the amount of charge in a predetermined state of charge is uniform among the plurality of cells” {being interpreted as less than a second threshold} and “when the assembled battery is discharged or charged thereafter, the states of charge of the plurality of cells will be uniform in the predetermined state of charge” ¶[17]
While Murao’s application of this process on a lithium ion battery ¶[53] inherently means the battery would have a SOC-OCV characteristic curve with a flat area in which a change rate of an open circuit voltage with respect to a charge rate is equal to or lower than a predetermined value, Murao does not explicitly show this characteristic. It is known, however, that as Murao demonstrates a charging state from 0% to 100% SOC, that the voltage will be below the flat area before it reaches 0% SOC, and thus that feature is taught.
Murao is silent to the absolute value of the difference of full charge capacities and charge rate of the battery cells. One having ordinary skill in the art would readily understand, in the context of battery equalization, that the control system is concerned with the magnitude of the difference between the charge rate of the first and second battery cells while performing equalization. A negative difference in full charge capacity or charge rate holds no physical meaning, much like the negative value for elapsed time or distance.
Dependent Claim 2, Murao teaches the following:
An equalization control device as stated in claim 1,
where the voltage of the first cell and the voltage of the second cell are lower than the lower limit voltage of the flat area (as stated in Claim 1, Murao’s application of this process on a lithium ion battery ¶[53] inherently means the battery would have a SOC-OCV characteristic curve with a flat area in which a change rate of an open circuit voltage with respect to a charge rate is equal to or lower than a predetermined value.)
when a value of a difference between a full charge capacity of the first cell and a full charge capacity of the second cell is less than the first threshold (s2 of Fig. 4 leads to Fig. 5, Fig. 8 – s37; ¶’s[57, 81, 82, 89, 90 esp. 89, 90] discloses that the cell optimizing/equalizing process is carried out when the difference between the full charge capacities of the respective cells, i and the cell with the smallest full charge capacity, j, i.e. Q[i] – Q[j] is greater than the upper limit {interpreted as the first threshold}),
the control unit performing equalization such that the value of a difference between the voltage of the first cell and voltage of the second cell is less than a third threshold (Fig. 2-9, esp, Fig. 3 supported by ¶[57] shows that the voltage differences between different cells becomes less than a predetermined threshold after optimization {equalization}). Additionally, Murao teaches of obtaining the OCV during equalization, discharging a cell with a voltage above its target voltage and terminating the discharge when the cell reaches its target voltage ¶’s[56,60].
Murao is silent to the absolute value of the difference of full charge capacities and charge rate of the battery cells. One having ordinary skill in the art would readily understand, in the context of battery equalization, that the control system is concerned with the magnitude of the difference between the charge rate of the first and second battery cells while performing equalization. A negative difference in full charge capacity or charge rate holds no physical meaning, much like the negative value for elapsed time or distance.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Akaishi et al. (U.S. 20200136399) in view of Kikuchi (U.S. 20150137763) further in view of Hu et al. (U.S. 20220153168).
Independent Claim 1, Akaishi teaches the following:
An equalization control device for equalizing a plurality of battery cells for a battery including the battery cells (Fig. 1 – battery control device 50, abstract, ¶’s[2, 3] disclosing a battery control device that controls a battery assembly consisting of a plurality of battery cells for homogenizing (being interpreted as equalizing) the states of charge of a plurality of battery cells);
and having an SOC-OCV characteristic curve with a flat area (Fig. 2, abstract, ¶’s[7, 35, 41]) in which a change rate of an open circuit voltage with respect to a charge rate is equal to or lower than a predetermined value (abstract, ¶’s[5, 7] mentioning lithium iron phosphate (LFP) battery pack which inherently possesses features such as the open circuit voltage corresponding to the SOC of the cell is within the voltage range, ¶[7] explicitly mentioning that a rate of change of an open circuit voltage with respect to a power storage amount is smaller than that in an adjacent region);
the equalization control device comprising:
an acquisition unit for acquiring values of full charge capacities and voltages of a first cell and a second cell included in the battery cells (Fig. 1 – determining unit 51, controller 52, ¶’s[41, 42] where determining unit 51 obtains the open circuit voltage of each of the battery cells and controller 52 controls and keeps the power storage amount (SOC) of the battery cells);
and a control unit for controlling equalization of the battery cells (Fig. 1 – battery control device 50, processor 53, Fig. 9, ¶[45] explicitly mentioning that the processor 53 performs a battery homogenization process);
wherein in a case where a voltage of the first cell and a voltage of the second cell are lower than a lower limit voltage of the flat area (¶’s[7, 41] explicitly mentions whether the open circuit voltage of each battery cell is lower than a lower-limit voltage of the flat region of the SOC-OCV characteristic curve); and
the control unit performs equalization on the low-voltage side of the flat area in preference to the high-voltage side (¶’s[105, 106]).
Akaishi is silent to the absolute value of the differences of full charge capacities of the first and second cells being equal to or greater than a first threshold as the precursor to performing equalization. Akaishi is also silent to the equalization process in which an absolute value of a difference between a charge rate of the first cell and a charge rate (see claim objection interpretation) of the second cell at a time of full charge is less than a second threshold.
Kikuchi discloses of an equalization method of an electrical storage system {battery] with plurality of electrical storage elements {battery cells} connected in series (abstract, Fig. 3 – single cells 11)
where the acquisition unit acquires the value of a difference between a full charge capacity of the first cell and a full charge capacity of the second cell (cells in Fig. 2 of system in Figs. [1-3]) is equal to or greater than a first threshold (abstract, s103 of Fig. 7, see para's [62, 66-69, 89, esp. 62, 69, 89] further where a noticeable difference means it is above the tolerance value of the sensor/processor; ¶’s[89, 104] disclose that the controller 30 calculates a SOC difference that arises due to a difference in full charge capacity FCC[0] between a reference cell 11 and full charge capacity FCC[k] of a comparative cell 11 from a current value and a voltage value in the reference cell and each comparative cell); and
the control unit performs equalization such that the value of a difference between a charge rate of the first cell and a charge rate of the second cell is less than a second threshold (Fig. 7 full method, structure of Figs. [2, 3], equalization charts of Figs. [4-6]); ¶’s[113-120] disclose that the controller 30 calculates an equalization stopping SOC, compares each cell’s current SOC with that stopping SOC and discharges each comparative cell until the stopping SOC value is reached.)
Kikuchi teaches that through such technique, SOC variations due to full charge capacity variations can be acquired, and the equalizing process is not carried out for SOC variations due to full charge capacity variations. Thus, it is possible to suppress a situation where the equalizing process is frequently carried out on the basis of SOC variations due to full charge capacity variations and, as a result, electric energy stored in the single cells 11 tends to be wastefully consumed ¶’s[7, 10, 128].
It would have been obvious to one having ordinary skill in the art, prior to the effective filing date of the claimed invention, to modify the teaching of Akaishi with Kikuchi to perform equalization process as to minimize the wasteful electrical power consumption.
Akaishi doesn’t explicitly disclose of an equalization process with the value of a difference between a charge rate of the first cell and a charge rate of the second cell is taken at a time of full charge.
Hu teaches of a battery pack with plurality of battery cells wherein the equalization process is performed such that the value of a difference between a charge rate of the first cell and a charge rate of the second cell at a time of full charge is less than a second threshold (¶’s[12, 14-18, esp. 16] disclose that if the difference in initial SOCs between the “new” and “old” cells is equal to ΔSOC when charging it initiated for all the cells, the “new” and “old” cells will achieve 100% state of charge at the same time-thus achieving a balanced pack. In this example, 100% is used as the target value for balancing (being interpreted as at a time of full charge.) Hu teaches in ¶’s[13, 17] that discharging the “new” cells to the 20% lower limit value wastes energy. If all the cells were simply recharged at the same time, the “new” and “old” cells would not achieve 100% SOC at the same time. To remedy this situation, Hu proposes to individually discharge the “new” cells such that their SOC become equal to an initial SOC at which all cells would achieve 100% if charged at the same time. Then, all the cells can be recharged at the same time, resulting in a balanced peak.
It would have been obvious to one having ordinary skill in the art, prior to the effective filing date of the claimed invention, to modify the teaching of Akaishi in view of Kikuchi, with Hu, to perform the equalization process such that all cells reach the full charge state at the same time within a tolerance to eliminate any imbalance between the cells with different charge capacities while minimizing stored energy wastage.
Akaishi is silent to teaching the absolute value difference of full charge capacities and charge rate of battery cells.
One having ordinary skill in the art would readily understand, in the context of battery equalization, that the control system is concerned with the magnitude of the difference between the charge rate of the first and second battery cells while performing equalization. A negative difference in full charge capacity or charge rate holds no relative physical meaning, since a negative value for one point of view is a positive value from another point of view (i.e. B1-voltage – B2-voltage may be negative, but the positive version is B2-voltage – B1 voltage, and if the differences between the batteries are taken into account, then this relative difference is already considered, and is thus equivalent to absolute value differences)
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Yoshida (U.S. 20140159664) teaches of a battery pack charge balance system with plurality of battery cells having different full charge capacities where the cells are charged and discharged such that their full charge capacity difference and current amount difference become mutually substantially the same ¶’s[65-67].
Hamada (U.S. 20240053411) teaches of storage battery management device for managing an assembly of series connected storage batteries including a voltage equalization circuit that performs constant current control to reduce the voltage difference of each storage battery by transferring electric charge among the storage batteries; a coulomb counting processing unit that calculates the (full charge) capacity of each storage battery; a voltage equalization control unit that causes the voltage equalization circuit to perform the constant current control. If the average voltage is within the plateau region of SOC-OCV characteristic curve, the voltage equalization control unit continues constant current control when the capacity difference is ≥ a first capacity difference, and stops constant current control when the capacity difference reaches a second capacity difference (abstract).
Takahashi et al. (U.S. 20120065824) discloses a battery with a control apparatus for a vehicle capable of controlling the vehicle by estimating the SOC of a battery having a long plateau region with high accuracy. The control apparatus estimates a status of charge (SOC) by a first estimation method by temporarily changing the SOC of a battery (B) so that the SOC of the battery (B) falls within a first region in the case a period, during which the estimated value of the status of charge of the battery (B) falls within a second region, exceeds a prescribed period (abstract, ¶[10]).
Kang et al. (U.S. 20100085009) teaches an equalization process that equalizes SOC difference between SOC of each cell (C1 to Cn) and an average SOC of the total cells (C1 to Cn). The SOC deviation taught for the equalization process is not limited to any specific method for defining an SOC deviation of a cell (¶[76]). Nakamoto et al. (U.S. 20140104739) teaches of an equalization process which includes a detector, configured to detect a variation value corresponding to an amount of charge of the electric storage device, a controller, configured to determine whether the variation value detected by the detector is equal to or lower than an opening threshold, and execute an opening process to switch a state of the relay from a closed state to an open state if the variation value is equal to or lower than the opening threshold (¶[8,14,16]).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAWHID PRANTO whose telephone number is (571)270-3205. The examiner can normally be reached on Monday through Friday 9am-6pm (often working later), M-F, ET. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, JULIAN HUFFMAN can be reached on (571)272-2147. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TAWHID M PRANTO/Examiner, Art Unit 2859
/JULIAN D HUFFMAN/Supervisory Patent Examiner, Art Unit 2859
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