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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) were submitted on 04/05/2023, 06/03/2024, and 01/29/2025. The submissions are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the following must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
There are various periods claimed by claims 10-13 that are not depicted in the drawings. Thus, it is unclear to the examiner how each of these periods is arranged in sequence.
“first period” (claims 10-11)
“third current” (claim 11)
“second period” (claims 12-13)
“the charging period” (claim 10)
“the discharge period” (claim 12)
“ON period of the first and second switches” (claims 11, 13)
“OFF period of the first and second switches” (claim 12)
“ON period of the third and fourth switches” (claim s 11, 13)
“OFF period of the third and fourth switches” (claim 14)
Corrected drawing sheets in compliance with 37 CFR 1.121(d) and/or amendment to the specification to add the reference character(s) in the description in compliance with 37 CFR 1.121(b) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
Claims 1, 3-5, and 9 are objected to because of the following informalities:
Claim 1, line 12 recites “the ON period”, which should be revised to “[[the]] an ON period” to ensure proper antecedent basis.
Claims 3-5 recite “in a condition”, which should be revised to “in [[a]] the condition” because the condition is introduced prior in claim 1, lines 10-12.
In claim 9, line 7, the word “one” appears to be erroneous and is ignored for examination purposes. Remove it.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-15 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1, lines 1-2 are indefinite as to which feature is being modified by “comprising: …”. For examination purposes, it is assumed “comprising” modifies the “cell balancing circuit”, rather than the “plurality of cells”. Thus, it is suggested to revise to “[[comprising]] wherein the cell balancing circuit comprises:”
Claim 1, line 8 is indefinite in the language “except the central battery cell among the plurality of cells. It may be interpreted (as is assumed for examination) that the “second battery cell” is not the “central battery cell”. Alternatively, it may be interpreted that the “third switch”, “second winding wire”, and “fourth switch” are not coupled in series with the “central battery cell”.
Claim 1, line 10 recites “during the charge or discharge”. There is insufficient antecedent basis for this limitation. The claim does not define “the charge or discharge” prior. For examination purposes, it is assumed this could be the charging or discharging of anything, including of individual cells to each other.
Claim 1, line 11 recites “the outer battery cell”. There is insufficient antecedent basis for this term in the claim language. For examination purposes, it is assumed “the outer battery cell” may be any cell in the “plurality of cells” other than the “central battery cell”.
Claim 2, line 6 recites “the current”. This language is indefinite as to which of the prior-introduced currents (“first side current”, “charging current”, “discharging current”) is being referred to. For examination purposes, it is assumed “the current” of claim 2, line 6, is referring to the “first side current” introduced in claim 1, line 13.
Claim 2, lines 7-8 recite “the turning-off of the first switch and the second switch”. There is insufficient antecedent basis for this limitation. No prior claim language describes turning off these two switches. For examination purposes, it is assumed a prior limitation exists to require turning off the first switch and the second switch.
Claim 8, line 9 recites “the determined result”. There is insufficient antecedent basis for this term in the claim language. For examination purposes, it is assumed the “determined result” is the result of comparing the “deviation” with the “predetermined threshold value” (lines 5-8).
Claim 8, line 14 recites “the predetermined deviation”. There is insufficient antecedent basis for this term in the claim language. For examination purposes, it is assumed “the predetermined deviation” is revised to “the [[predetermined]] deviation” to ensure antecedent basis from claim 8, line 5.
Claim 8 introduces “a battery pack”, however dependent claims 9-15 are indefinite for lacking antecedent basis for “the battery system”. It is assumed the “battery pack” and the “battery system” are the same.
Claim 10, line 3 recites “the charging period”. There is insufficient antecedent basis for this term in the claim language. For examination purposes, it is assumed the “charging period” comprises any period of time where charge is transferred.
Claims 12 and 14-15 each recite at least a subset of the following terms, each of which has insufficient antecedent basis.
“the first switch”
“the second switch”
“the third switch”
“the fourth switch”
“the first winding wire”
“the second winding wire”
For examination purposes, it is assumed each of claims 12 and 14-15 is dependent on claim 9, which would provide antecedent basis.
Claims 10 and 12 recite “switches the first to fourth switches”. This language is unclear whether it is switching from the first switch to the fourth switch or, alternatively, if each of the first, second, third, and fourth switches are switching. For examination purposes, it is assumed each of the first, second, third, and fourth switches are switching during the “first period” of claim 10 and during the “second period” of claim 12.
Claim 12 recites “among the discharge period”, which has an unclear meaning in the context of surrounding language. For examination purposes, it is assumed the “second period” occurs during a “discharge period”
Claims 3-7 are further rejected for their dependency on other rejected claims.
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.
Claims 1-2, and 4 are rejected under 35 U.S.C. 102(a)(1)/102(a)(2) as being anticipated by Li et al. (US 2011/0241622 A1).
Regarding Claim 1, Li discloses a cell balancing circuit (combo of “transformer 703”, “first switch array 706”, and “second switch array 707”; see annotated Fig. 7, included infra) connected to a plurality of cells (“N serial coupled battery cells 702_1-702_N”; Fig. 7; ¶ [76]) connected in series, comprising the following features.
PNG
media_image1.png
921
1026
media_image1.png
Greyscale
Li further discloses a first switch (“switch SA_2”; Fig. 7), a first winding wire (“first winding 704”; Fig. 7), and a second switch (“switch SB_2”; Fig. 7) coupled in series between both terminals of a central battery cell (“battery cell 702_2”; Fig. 7) among the plurality of cells (702_1-702_N).
Li further discloses a third switch (“switch SC_1”; Fig. 7), a second winding wire (“second winding 705”; Fig. 7), and a fourth switch (“switch SD_1”; Fig. 7) coupled in series (see “Fig. 7 – annotated for series path”, included infra) between a positive electrode of a first battery cell (“battery cell 702_N”; Fig. 7) and a negative electrode of a second battery cell (“battery cell 702_1”; Fig. 7) except the central battery cell (702_2) among the plurality of cells (702_1-702_N).
PNG
media_image2.png
872
1107
media_image2.png
Greyscale
Li further discloses the first winding wire (704) and the second winding wire (705) form a transformer (“transformer 703”; Fig. 7).
Li further discloses during the charge or discharge (Li’s disclosed operations, including that of Fig. 8, occur “during a charging process” or “during a discharging process” per ¶ [3]), in a condition (“NO” response to step 810: “V1 – V2 < VTHR2?”; Fig. 8; ¶ [90]: “if the difference is not lower than the second threshold … the battery cells 702_1-702_N are unbalanced”; per ¶ [77-80], when the difference is greater than the “second threshold, e.g., 50 mV”, then “the battery cells 702_1-702_N are unbalanced”) that a cell voltage difference (Fig. 8, step 810: “V1 – V2”; ¶ [77]: “a difference between a maximal voltage and a minimal voltage among the voltages of the battery cells 702_1-702_N”; see note included infra) between the central battery cell (702_2 represented by voltage “V1” or “V2” when having the “minimal voltage” or “maximal voltage” per ¶ [76-80, 88]) and the outer battery cell (702_1; represented by voltage “V1” or “V2” when having the “minimal voltage” or “maximal voltage” per ¶ [76-80, 88]) is greater than or equal to a predetermined threshold value (Fig. 8, step 810: “VTHR2”; ¶ [79, 89]: “second threshold, e.g., 50 mV”), the following occurs.
NOTE: The example balancing operation that is most explicitly described in Li’s ¶ [87-92] is for moving charge from “702_1” with maximum voltage “V1” to “702_N” with minimum voltage “V2”. However, these are simply two cells picked out for example (¶ [88]: “e.g.”). Per ¶ [86], this circuit is configured to “balance any two cells in the battery cells 702_1-702_N”. Thus, one can interpret “V1” as representing the voltage of central battery cell “702_2” (instead of “702_1”) when it has the maximum voltage among “702_1-702_N”. Further, one can interpret “V2” as representing the voltage of outer battery cell “702_1” when it has the minimum voltage among “702_1-702_N”.
Li further discloses during the ON period (“first period TON”; Fig. 3; described in ¶ [42-44] with respect to Fig. 2 embodiment, but also applicable to Fig. 7 embodiment per ¶ [108]) of the first switch (“SA_2”, turned on as part of the “first switch set”; ¶ [91]) and the second switch (“SB_2”, turned on as part of the “first switch set”; ¶ [91]), a first side current (“current I1 can be conducted to flow from the first battery cell 702_1 to the first winding”; ¶ [91]; also functions for central battery cell “702_2” instead of “702_1”, per examiner interpretation in note, included supra) as a part of a charging current (“I1” can be interpreted to be charging the first winding wire “704”; see note included infra) or a discharging current (“I1” is discharging from central battery cell “702_2”; when the battery pack is discharging per ¶ [3, 54, 108], current “I1” is part of a larger discharging current out of the full battery pack; see note included infra) flows through the first switch (SA_2), the first winding wire (704), and the second switch (SB_2).
NOTE: The “charging current” and “discharging current” are subject to a broad interpretation such that they may be currents to charge/discharge any component, not necessarily the battery pack as a whole. Claim 8’s language is more limiting for this subject matter and resulted in the incorporation of an additional reference (Bodkin et al., US 2013/0002201 A1) in the claim 8 rejection included infra.
PNG
media_image3.png
934
1023
media_image3.png
Greyscale
Regarding Claim 2, Li discloses the cell balancing circuit of claim 1.
Li further discloses that, in a condition (“NO” response to step 810; Fig. 8) that the cell voltage difference (V1 – V2) between the central battery cell (“702_2” with voltage “V1” or “V2”) and the outer battery cell (“702_1” with voltage “V1” or “V2”) during the charging (outer battery cell “702_1” is being charged, at least with the balancing charge from central battery cell “702_2”; further, the full battery pack may be getting charged per ¶ [3]; further, the first winding wire “704” is getting charged by current from central battery cell “702_2”) is greater than or equal to the predetermined threshold value (VTHR2), the following occurs.
See the “Fig. 3 - annotated for claims 2-3 & 10-11”, included infra, which depicts the switching sequence for transferring charge from the central cell to the outer cell and uses the first winding wire (704) as the primary winding per ¶ [81-82]. Though this figure is described in ¶ [42-44] with respect to the Fig. 2 embodiment, the switching pattern is also applicable to the Fig. 7 embodiment per ¶ [108].
Li further discloses the first switch (SA_2) and the second switch (SB_2) are turned-on (each is part of the “first switch set” which is turned on to connect “V1” of central battery cell “702_2” across the first winding “704” in step 814; Fig. 8).
Li further discloses an on duty (“duty cycle D1”; ¶ [42-43]) of the first switch (SA_2) and the second switch (SB_2) is controlled based on the current (per ¶ [43], equation (3), “D1” is determined based on first side current “I1”) flowing to the first winding wire (704).
Li further discloses the third switch (SC_1) and the fourth switch (SD_1) are turned-on (each is part of the “second switch set” which is turned on to connect “V2” of outer battery cell “702_1” across the second winding “705” in step 818; Fig. 8) after the turning-off (see annotated Fig. 3) of the first switch (SA_2) and the second switch (SB_2).
PNG
media_image4.png
834
1065
media_image4.png
Greyscale
Regarding Claim 4, Li discloses the cell balancing circuit of claim 1.
Li further discloses that, in a condition (“NO” response to step 810; Fig. 8) that the cell voltage difference (V1 – V2) between the central battery cell (“702_2” with voltage “V1” or “V2”) and the outer battery cell (“702_1” with voltage “V1” or “V2”) during the discharging (central battery cell “702_2” is discharging to balance the outer battery cell “701_1”; further, the full battery pack may be discharging per ¶ [3, 54, 108]) is equal to or greater than the predetermined threshold value (VTHR2), the following occurs.
See the “Fig. 3 - annotated for claims 4-5 & 12-13”, included infra, which depicts the switching sequence for transferring charge from the outer cell to the central cell and uses the second winding wire (705) as the primary winding per ¶ [83-84]. Though this figure is described in ¶ [42-44] with respect to the Fig. 2 embodiment, the switching pattern is also applicable to the Fig. 7 embodiment per ¶ [108].
Li further discloses the third switch (SC_1) and the fourth switch (SD_1) are turned-on (when transferring from outer cell “702_1” to central cell “702_2” using the second winding wire “705” as the primary, then “SC_1” and “SD_1” are the “first switch set SCD_1” per ¶ [83-84]; thus, both are on during the “TON” period of Fig. 3).
Li further discloses an on duty (“duty cycle D1”; ¶ [42-43]) of the third switch (SC_1) and the fourth switch (SD_1) is controlled based on the current (per ¶ [43], equation (3), “D1” is determined based on first side current “I1”; as modified by ¶ [83-84], “I1” is the current through the second winding wire “705”; however, the switch timing of is based the “current IN induced in the first winding 704”) flowing to the first winding wire (704).
Li further discloses the first switch (SA_2) and the second switch (SB_2) are turned-on (after the interval TON, the second switch set “SAB_N” is turned back on; ¶ [83-84]) after the turning-off (after the interval TON, the first switch set “SCD_1” is turned off; ¶ [83-84) of the third switch (SC_1) and the fourth switch (SD_1).
PNG
media_image5.png
833
1065
media_image5.png
Greyscale
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.
Claims 3 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 2011/0241622 A1) in view of Densham et al. (US 2014/0084871 A1; hereinafter “Den”).
Regarding Claim 3, Li discloses the cell balancing circuit of claim 2.
Li further discloses a condition (“NO” response to step 810; Fig. 8) that the cell voltage difference (V1 – V2) between the central battery cell (“702_2” with voltage “V1” or “V2”) and the outer battery cell (“702_1” with voltage “V1” or “V2”) during the charging (outer battery cell “702_1” is being charged, at least with the balancing charge from central battery cell “702_2”; further, the full battery pack may be getting charged per ¶ [3]; further, the first winding wire “704” is getting charged by current from central battery cell “702_2”) is greater than or equal to the predetermined threshold value (VTHR2).
See the “Fig. 3 - annotated for claims 4-5 & 10-11”, included supra, which depicts the switching sequence for transferring charge from the central cell to the outer cell and uses the first winding wire (704) as the primary winding per ¶ [81-82].
Li further discloses a turning on state (each is part of the “first switch set” which is turned on to connect “V1” of central battery cell “702_2” across the first winding “704” in step 814; Fig. 8) of the first switch (SA_2) and the second switch (SB_2).
Li further discloses the first switch (SA_2) and the second switch (SB_2) are turned-off based on the first side current (per ¶ [43], equation (3), “D1” is determined based on first side current “I1”).
Li does not disclose “the first side current reaches a predetermined reference value, and the first switch and the second switch are turned-off”.
Den teaches the first side current (“input current IP”; Fig. 1B) reaches a predetermined reference value (“peak current level IPP”, reached during “first duration T1”; Fig. 1B), and the input-side switch(es) (“108” in Fig. 1A; “208” in Fig. 5) is/are turned-off (when the first duration T1 expires … switch 108 is turned off; see note, included infra).
NOTE: Den is not relied upon to teach turning off both the first switch and the second switch. Den teaches turning off the input-side switch when the input-side current reaches the predetermined reference value. As discussed supra, Li teaches controlling the first side current, i.e. the input side current, by turning off the first switch and second switch, i.e. the input side switch(es). Because Den also teaches turning off an input-side switch to block the input-side current, one of ordinary skill in the art would understand the teachings of Den can be applied to the first switch and second switch of Li.
PNG
media_image6.png
882
1347
media_image6.png
Greyscale
Den further teaches to turn off the input-side switch(es) when the input-side current reaches a predetermined reference value to accurately control the voltage conversion by quickly responding to changes in the input-side current in response to changes in the varying voltage across a battery cell (¶ [2, 14, 16, 22]).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by Li to turn off the first and second switches when the first side current reaches a predetermined reference value, based on the teachings of Den, to more accurately control the voltage conversion of the transformer by quickly responding to changes in the input-side current that occur with the varying battery cell voltages.
Regarding Claim 5, Li discloses the cell balancing circuit of claim 4.
Li further discloses a condition (“NO” response to step 810; Fig. 8) that the cell voltage difference (V1 – V2) between the central battery cell (“702_2” with voltage “V1” or “V2”) and the outer battery cell (“702_1” with voltage “V1” or “V2”) during the discharge (central battery cell “702_2” is discharging to balance the outer battery cell “701_1”; further, the full battery pack may be discharging per ¶ [3, 54, 108]) is equal to or greater than the predetermined threshold value (VTHR2).
See the “Fig. 3 - annotated for claims 4-5 & 12-13”, included supra, which depicts the switching sequence for transferring charge from the outer cell to the central cell and uses the second winding wire (705) as the primary winding per ¶ [83-84].
Li further discloses the turning on state (when transferring charge from outer cell “702_1” to central cell “702_2” using second winding wire “705” as the primary per ¶ [83-84], each of “SC_1” and “SD_1” are the “first switch set SCD_1”, which are turned on during “TON” of Fig. 3) of the third switch (SC_1) and the fourth switch (SD_1).
Li further discloses the third switch (SC_1) and the fourth switch (SD_1) are turned-off (after “TON”; Fig. 3).
Li does not disclose “when the second side current reaches a predetermined reference value, the third switch and the fourth switch are turned-off”.
Den teaches when the input-side current (“input current IP”; Fig. 1B) reaches a predetermined reference value (“peak current level IPP”, reached during “first duration T1”; Fig. 1B), and the input-side switch(es) (“108” in Fig. 1A; “208” in Fig. 5) is/are turned-off (when the first duration T1 expires … switch 108 is turned off; see note, included infra).
NOTE: Den is not relied upon to teach turning off both the third switch and the fourth switch. Den teaches turning off the input-side switch when the input-side current reaches the predetermined reference value. As discussed supra, Li teaches controlling the second side current, i.e. the input side current, by turning off the third switch and fourth switch, i.e. the input side switch(es). Because Den also teaches turning off an input-side switch to block the input-side current, one of ordinary skill in the art would understand the teachings of Den can be applied to the third switch and fourth switch of Li.
Den further teaches to turn off the input-side switch(es) when the input-side current reaches a predetermined reference value to accurately control the voltage conversion by quickly responding to changes in the input-side current in response to changes in the varying voltage across a battery cell (¶ [2, 14, 16, 22]).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by Li to turn off the third and fourth switches when the second side current reaches a predetermined reference value, based on the teachings of Den, to more accurately control the voltage conversion of the transformer by quickly responding to changes in the input-side current that occur with the varying battery cell voltages.
Claims 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 2011/0241622 A1) in view of Badalec (DE 4010100 A1; hereinafter “Bada”).
Claims 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 2011/0241622 A1) in view of Denso (DENSO Developed New Generation Battery-Monitoring Integrated Circuit for Lithium-ion Batteries, a Key component of Battery ECUs; published 08/13/2020, www.denso.com), Densham et al. (US 2014/0084871 A1; hereinafter “Den”), Badalec (DE 4010100 A1; hereinafter “Bada”).
NOTE: The rejections are combined for claims 6 and 14 because the dependent limitations are equivalent. The rejections are combined for claims 7 and 15 because the dependent limitations are equivalent.
Regarding Claims 6 and 14, Li discloses the cell balancing circuit of claim 1 and the combination of Li, Denso, and Bodkin teaches the battery pack/system of claim 8.
The “Fig. 7 – annotated for claims 6-7, 14-15”, included infra, includes detailed mapping for the two terminals of each switch and winding from Li.
Li further discloses a first terminal of the first switch (SA_2) and a first terminal of the first winding wire (704).
Li further discloses a first terminal of the second switch (SB_2) and a second terminal of the first winding wire (704).
Li further discloses a second terminal of the first switch (SA_2) is connected to the second terminal of the first winding wire (704).
Li further discloses a second terminal of the second switch (SB_2) is connected to the first terminal of the first winding wire (704).
PNG
media_image7.png
846
1371
media_image7.png
Greyscale
Though Li discloses the terminals of each of the first and second switch, along with their connections to the first winding wire, Li does not disclose “a first diode connected between a first terminal of the first switch and a first terminal of the first winding wire; and a second diode connected between a first terminal of the second switch and a second terminal of the first winding wire”.
Bada teaches (see annotated Fig. 4, included infra) a first diode (“primary freewheeling diode D2”) connected between a first terminal of the first switch (S2) and a first terminal of the first winding wire (annotated as “primary winding wire”).
Bada further teaches a second diode (“primary freewheeling diode D3”) connected between a first terminal of the second switch (S1) and a second terminal of the first winding wire (“primary winding wire”).
Bada further teaches a second terminal of the first switch (S2) is connected to the second terminal of the first winding wire (“primary winding wire”).
Bada further teaches a second terminal of the second switch (S1) is connected to the first terminal of the first winding wire (“primary winding wire”).
PNG
media_image8.png
814
1480
media_image8.png
Greyscale
Bada further teaches the two diodes arranged on the input/primary side of the transformer-based converter to enable the free wheeling of current through the diodes back to the supply cell(s) in the event of damage on the secondary side of the transformer, thus protecting primary-side components by avoiding undesirable increases in voltage. (page 4, last paragraph – page 5, first paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by Li to incorporate the first and second diodes, as taught by Bada, to protect the cell balancing circuit by preventing voltage spikes.
Regarding Claims 7 and 15, Li discloses the cell balancing circuit of claim 1 and the combination of Li, Denso, and Bodkin teaches the battery pack/system of claim 8.
The “Fig. 7 – annotated for claims 6-7, 14-15”, included supra in the claim 6 section, includes detailed mapping for the two terminals of each switch and winding from Li.
Li further discloses a first terminal of the third switch (SC_1) and a first terminal of the second winding wire (705).
Li further discloses a first terminal of the fourth switch (SD_1) and a second terminal of the second winding wire (705).
Li further discloses a second terminal of the third switch (SC_1) is connected to the second terminal of the second winding wire (705).
Li further discloses a second terminal of the fourth switch (SD_1) is connected to the first terminal of the second winding wire (705).
Though Li discloses the terminals of each of the third and fourth switch, along with their connections to the second winding wire, Li does not disclose “a third diode connected between a first terminal of the third switch and a first terminal of the second winding wire; and a fourth diode connected between a first terminal of the fourth switch and a second terminal of the second winding wire”.
As discussed supra in the claim 6 rejection, Bada teaches “a first diode connected between a first terminal of the first switch and a first terminal of the first winding wire; and a second diode connected between a first terminal of the second switch and a second terminal of the first winding wire, a second terminal of the first switch is connected to the second terminal of the first winding wire, and a second terminal of the second switch is connected to the first terminal of the first winding wire” (see detailed mapping included supra).
Bada’s teachings are not explicitly with respect to a third diode, a third switch, a fourth diode, a fourth switch, and a second winding wire. However, because the base reference Li teaches the second winding wire (705) may be used as the input/primary winding to transfer energy to the output/secondary winding (first winding wire 704), one of ordinary skill in the art would understand that Bada’s teachings for these features are also applicable to the secondary side of Li’s converter circuit. Bada’s primary-side circuit arrangement of switches, a battery cell, and a winding are analogous to each of the primary and secondary sides of the bidirectional circuit arrangement disclosed by Li. Thus, Bada’s teachings for the arrangements of the first/second diodes can be applied to incorporate third/fourth diodes in the arrangement with the third/fourth switches and second winding wire disclosed by Li.
Bada further teaches the two diodes arranged on the input/primary side of the transformer-based converter to enable the free wheeling of current through the diodes back to the supply cell(s) in the event of damage on the secondary side of the transformer, thus protecting primary-side components by avoiding undesirable increases in voltage. (page 4, last paragraph – page 5, first paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by Li to incorporate the third and fourth diodes, as taught by Bada, to protect the cell balancing circuit by preventing voltage spikes.
Thus, the combination of Li and Bada teaches a third diode (incorporated “D2” from Bada) connected between a first terminal of the third switch (Li: “SC_1”; Bada equivalent: “S2”) and a first terminal of the second winding wire (Li: “705”; Bada equivalent: “primary winding wire”).
The combination of Li and Bada further teaches a fourth diode (incorporated “D3” from Bada) connected between a first terminal of the fourth switch (Li: “SD_1”; Bada equivalent: “S1”) and a second terminal of the second winding wire (Li: “705”).
The combination of Li and Bada further teaches a second terminal of the third switch (Li: “SC_1”; Bada equivalent: “S2”) is connected to the second terminal of the second winding wire (Li: “705”).
The combination of Li and Bada further teaches a second terminal of the fourth switch (Li: “SD_1”; Bada equivalent: “S1”) is connected to the first terminal of the second winding wire (Li: “705”).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US 2015/0035495 A1; hereinafter “Yosh”) in view of Denso (DENSO Developed New Generation Battery-Monitoring Integrated Circuit for Lithium-ion Batteries, a Key component of Battery ECUs; published 08/13/2020, www.denso.com).
NOTE: As of the current date, the Denso reference is available at the following link:
https://www.denso.com/global/en/news/newsroom/2020/20201013-g01/
Regarding Claim 8, Yosh discloses a battery pack (“battery pack 10”; Fig. 1) including a plurality of cells (“battery cells 100”, drawn as “Cell1-CellN”; Figs. 1, 12) connected in series (¶ [31]: “plurality of battery cells 100 are connected in series to each other”).
Yosh further discloses a cell monitoring circuit (“voltage and current measurement unit 340”; Fig. 1; ¶ [44]: “340 measures the voltage of each of the plurality of battery cells 100”) for measuring a cell voltage of each of the plurality of cells (100).
Yosh further discloses a main control circuit (“battery control unit 400”; Fig. 1) that determines whether a deviation (“voltage difference” between “highest voltage” and “lowest voltage” per ¶ [88-92]; Fig. 3, step S142; Fig. 5b depicts “highest voltage Va”, “lowest voltage “Vb”, and deviation “ΔV”) between a cell voltage of a central battery cell (“Cell2”; Figs. 1, 12; may be either the “maximum voltage cell” or the “minimum voltage cell” at any point in time) among the plurality of cells (100) and a cell voltage of an outer battery cell (“Cell1”; Figs. 1, 12; may be either the “maximum voltage cell” or the “minimum voltage cell” at any point in time) except for the central battery cell (“Cell2”) among the plurality of cells (100) is a predetermined threshold value or more (Fig. 3, step S142: “equal to or greater than first reference voltage value?”) based on a plurality of measured cell voltages (¶ [59]: “on the basis of the voltages measured by … 340”).
Yosh further discloses the main control circuit (400) controls a cell balancing operation (Fig. 3, step S150: “balance control: equalize voltage”; ¶ [58]: “400 performs balance control for equalizing the voltages of the battery cells 100 in which the voltage difference occurs, on the basis of the voltages measured”) based on the determined result (step S150 is executed for a “yes” response to step S142; Fig. 3) and the charging and discharging (step S150 is executed for a “yes” response to step S112: “is electrification performed?)”; Fig. 3; ¶ [45]: “400 can determine that the battery cell 100 is being electrified (charge or discharge is performed)”) of the battery pack (10).
Yosh further discloses a cell balancing circuit (combination of “battery control unit 400” of Figs. 1 & 11 and each of “second cell switch 206” and “third cell switch 208” of Fig. 12) that prevents a first current among a charging current from flowing (see “Fig. 12 - annotated for charging condition”, included infra; first current to “Cell2” is blocked by opening respective “206” and charging current is redirected around “Cell2” by closing respective “208”) to the central battery cell (“Cell2”) when the deviation is greater than the predetermined threshold value (“yes” response to step S142 indicates voltage difference exceeds “first reference voltage value”; Fig. 3) in the charging condition (“yes” response to S112 indicates “electrification” is being performed; Fig. 3; per ¶ [45], “electrification” is either “charge or discharge”) of the battery pack (10).
PNG
media_image9.png
833
1023
media_image9.png
Greyscale
Yosh further discloses the cell balancing circuit (400, 206, 208) prevents a second current among a discharging current from flowing (see “Fig. 12 - annotated for discharge condition”, included infra; second current to “Cell2” is blocked by opening respective “206” and discharging current is redirected around “Cell2” by closing respective “208”) to the central battery cell (“Cell2”) when the predetermined deviation is greater than the predetermined threshold value (“yes” response to step S142 indicates voltage difference exceeds “first reference voltage value”; Fig. 3) in the discharge condition (“yes” response to S112 indicates “electrification” is being performed; Fig. 3; per ¶ [45], “electrification” is either “charge or discharge”) of the battery pack (10).
PNG
media_image10.png
832
1020
media_image10.png
Greyscale
Though Yosh discloses a cell monitoring circuit for measuring the cell voltages, Yosh does not disclose “a cell monitoring integrated circuit (IC) for measuring a cell voltage of each of the plurality of cells”.
Denso teaches a cell monitoring integrated circuit (IC) (“new generation battery-monitoring integrated circuit”) for measuring a cell voltage (page 2, 4th paragraph: “detect battery voltage”) of each of the plurality of cells (page 2, 4th paragraph: “monitor 1.2 times more battery cells (25 ch/IC)”).
Denso further teaches a cell monitoring IC can minimize the size and cost of the hardware implementation by reducing the number of parts required to monitor the battery cells (page 3, 1st paragraph: “reduced the number of ICs and peripheral parts … to minimize the size and cost of battery ECUs”).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell monitoring circuit disclosed by Yosh to be an integrated circuit, as taught by Denso, to minimize the size and cost of the battery pack.
Claims 9-13 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US 2015/0035495 A1; hereinafter “Yosh”) in view of Denso (DENSO Developed New Generation Battery-Monitoring Integrated Circuit for Lithium-ion Batteries, a Key component of Battery ECUs; published 08/13/2020, www.denso.com) and Li et al. (US 2011/0241622 A1).
Regarding Claim 9, the combo of Yosh & Denso teaches the battery system of claim 8.
Though Yosh discloses the cell balancing circuit with a first battery cell, a second battery cell, and various switches, Yosh does not disclose the arrangement “wherein the cell balancing circuit includes: a first switch, a first winding wire, and a second switch coupled in series between both terminals of the central battery cell; and a third switch, a second winding wire, and a fourth switch coupled in series between a positive electrode of a first battery cell and a negative electrode of a second battery cell one among the plurality of cells, and the first winding wire and the second winding wire form a transformer”.
Li discloses the cell balancing circuit (703, 706, 707) includes the following features.
Li further discloses a first switch (“switch SA_2”; Fig. 7), a first winding wire (“first winding 704”; Fig. 7), and a second switch (“switch SB_2”; Fig. 7) coupled in series between both terminals of the central battery cell (“battery cell 702_2”; Fig. 7).
Li further discloses a third switch (“switch SC_1”; Fig. 7), a second winding wire (“second winding 705”; Fig. 7), and a fourth switch (“switch SD_1”; Fig. 7) coupled in series (see “Fig. 7 – annotated for series path”, included supra) between a positive electrode of a first battery cell (“battery cell 702_N”; Fig. 7) and a negative electrode of a second battery cell (“battery cell 702_1”; Fig. 7) one among the plurality of cells (702_1-702_N).
Li further discloses the first winding wire (704) and the second winding wire (705) form a transformer (“transformer 703”; Fig. 7).
Li teaches this arrangement of switches to connect the battery cells to transformer windings to improve the efficiency of the cell balancing circuit by enabling the transfer of charge between specific battery cells through the transformer, as controlled by the switches (¶ [47, 52, 54, 108, 111]).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by Yosh to incorporate the arrangement of switches and a transformer, as taught by Li, to improve the efficiency of the cell balancing circuit. The Yoshida drawing “Fig. 12 – annotated for modification from Li” illustrates the features incorporated from Li’s Fig. 7 into Yoshida’s Fig. 12.
PNG
media_image11.png
967
1172
media_image11.png
Greyscale
Regarding Claims 10-11, the combination of Yosh, Denso, and Li teaches the battery system of claim 9.
Yosh does not disclose “the cell balancing circuit switches the first to fourth switches during a first period in which the deviation is larger than the predetermined threshold value during the charging period to store the energy in the first winding wire by the first current and to transmit the stored energy in the first winding wire to the second winding wire”. (claim 10)
Yosh further does not disclose “during the first period, the first current flows in the first winding wire during an ON period of the first and second switches, and a third current is induced to the second winding wire during an OFF period of the first and second switches and an ON period of the third and fourth switches”. (claim 11)
See the Li “Fig. 3 - annotated for claims 2-3 & 10-11”, included supra, which depicts the switching sequence for transferring charge from the central cell to the outer cell and uses the first winding wire (704) as the primary winding per ¶ [81-82].
Li further teaches the cell balancing circuit (703, 706, 707) switches the first to fourth switches (SA_2, SB_2, SC_1, SD_1) during a first period (“period T”; Fig. 3 shows all four switches change state during “period T”) in which the deviation is larger than the predetermined threshold value (“NO” response to step 810 means “V1 – V2” is ≥ “VTHR2”; Fig. 8) during the charging period (cell balancing is controlled during each of charging and discharging per ¶ [3]) to store the energy in the first winding wire (704; operating as the primary/input winding per ¶ [81-82]) by the first current (I1) and to transmit the stored energy (¶ [82]: “energy … can be transferred to and accumulated in a magnetic core of the transformer 703”; ¶ [82]: “energy stored in the magnetic core … can be released”, causing “current IN induced in the second winding 705”) in the first winding wire (704) to the second winding wire (705; operating as the secondary winding per ¶ [81-82]).
Li further discloses during the first period (T), the first current (I1) flows in the first winding wire (704; operating as the primary/input winding per ¶ [81-82]) during an ON period (TON) of the first and second switches (SA_2, SB_2).
Li further discloses a third current (IN; ¶ [82]: “current IN induced in the second winding 705”) is induced to the second winding wire (705) during an OFF period (TON') of the first and second switches (SA_2, SB_2; Fig. 3 shows each is off during TON') and an ON period (TON') of the third and fourth switches (SC_1, SD_1; Fig. 3 shows each is on during TON').
Li teaches this operation of the switches and windings to improve the efficiency of the cell balancing circuit by enabling the transfer of charge between specific battery cells through the transformer, as controlled by the switches (¶ [47, 52, 54, 108, 111]).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by the combination of Yosh, Denso, and Li to incorporate operation of the switches and windings, as further taught by Li, to improve the efficiency of the cell balancing circuit.
Regarding Claims 12-13, the combination of Yosh, Denso, and Li teaches the battery system of claim 9.
Yosh does not disclose “the cell balancing circuit switches the first to fourth switches during a second period in which the deviation is larger than the predetermined threshold value among the discharge period to store the energy in the second winding wire and to transmit the stored energy in the second winding wire to the first winding wire”. (claim 12)
Yosh further does not disclose “during the second period, a third current flows in the second winding wire during an ON period of the third and fourth switches, and the second current is induced to the first winding wire during an OFF period of the third and fourth switches and an ON period of the first and second switches”. (claim 13)
See the Li “Fig. 3 - annotated for claims 4-5 & 12-13”, included supra, which depicts the switching sequence for transferring charge from the outer cell to the central cell and uses the second winding wire (705) as the primary winding per ¶ [83-84].
Li further discloses the cell balancing circuit (703, 706, 707) switches the first to fourth switches (SA_2, SB_2, SC_1, SD_1) during a second period (“period T”; Fig. 3 shows all four switches change state during “period T”) in which the deviation is larger than the predetermined threshold value (“NO” response to step 810 means “V1 – V2” is ≥ “VTHR2”; Fig. 8) among the discharge period (cell balancing is controlled during each of charging and discharging per ¶ [3]) to store the energy in the second winding wire (705; operating as the primary/input winding per ¶ [83-84]) and to transmit the stored energy (¶ [84]: “energy … can be transferred to and accumulated in the magnetic core of the transformer 703”; ¶ [84]: “energy stored in the magnetic core … can be released”, causing “a current IN induced in the first winding 704”) in the second winding wire (705) to the first winding wire (704; operating as the secondary winding per ¶ [83-84]).
Li further discloses during the second period (T), a third current (I1; ¶ [84]: “a current I1 can flow … to the second winding 705”) flows in the second winding wire (705; operating as the primary/input winding per ¶ [83-84]) during an ON period (TON) of the third and fourth switches (SC_1, SD_1).
Li further discloses the second current (IN; ¶ [84]: “current IN induced in the first winding 704”) is induced to the first winding wire (704) during an OFF period (TON') of the third and fourth switches (SC_1, SD_1; Fig. 3 shows each is off during TON') and an ON period (TON') of the first and second switches (SA_2, SB_2; Fig. 3 shows each is on during TON').
Li teaches this operation of the switches and windings to improve the efficiency of the cell balancing circuit by enabling the transfer of charge between specific battery cells through the transformer, as controlled by the switches (¶ [47, 52, 54, 108, 111]).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by the combination of Yosh, Denso, and Li to incorporate operation of the switches and windings, as further taught by Li, to improve the efficiency of the cell balancing circuit.
Claims 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US 2015/0035495 A1; hereinafter “Yosh”) in view of Denso (DENSO Developed New Generation Battery-Monitoring Integrated Circuit for Lithium-ion Batteries, a Key component of Battery ECUs; published 08/13/2020, www.denso.com), Li et al. (US 2011/0241622 A1), and Badalec (DE 4010100 A1; hereinafter "Bada").
Regarding Claim 14, the combination of Yosh, Denso, and Li teaches the battery system of claim 9.
The “Fig. 7 – annotated for claims 6-7, 14-15”, included supra, includes detailed mapping for the two terminals of each switch and winding from Li, which are incorporated into Yosh’s cell balancing circuit.
The combo of Yosh, Denso, and Li discloses a first terminal of the first switch (SA_2, incorporated from Li) and a first terminal of the first winding wire (704, from Li).
The combo of Yosh, Denso, and Li discloses a first terminal of the second switch (SB_2, from Li) and a second terminal of the first winding wire (704, from Li).
The combo of Yosh, Denso, and Li discloses a second terminal of the first switch (SA_2, from Li) is connected to the second terminal of the first winding wire (704, from Li).
The combo of Yosh, Denso, and Li discloses a second terminal of the second switch (SB_2, from Li) is connected to the first terminal of the first winding wire (704, from Li).
Though combo of Yosh, Denso, and Li discloses the terminals of each of the first and second switch, along with their connections to the first winding wire, Yosh does not disclose “a first diode connected between a first terminal of the first switch and a first terminal of the first winding wire; and a second diode connected between a first terminal of the second switch and a second terminal of the first winding wire”.
Bada teaches (see annotated Fig. 4, included supra) a first diode (“primary freewheeling diode D2”) connected between a first terminal of the first switch (S2) and a first terminal of the first winding wire (annotated as “primary winding wire”).
Bada further teaches a second diode (“primary freewheeling diode D3”) connected between a first terminal of the second switch (S1) and a second terminal of the first winding wire (“primary winding wire”).
Bada further teaches a second terminal of the first switch (S2) is connected to the second terminal of the first winding wire (“primary winding wire”).
Bada further teaches a second terminal of the second switch (S1) is connected to the first terminal of the first winding wire (“primary winding wire”).
Bada further teaches the two diodes arranged on the input/primary side of the transformer-based converter to enable the free wheeling of current through the diodes back to the supply cell(s) in the event of damage on the secondary side of the transformer, thus protecting primary-side components by avoiding undesirable increases in voltage. (page 4, last paragraph – page 5, first paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by the combination of Yosh, Denso, and Li to incorporate the first and second diodes, as taught by Bada, to protect the cell balancing circuit by preventing voltage spikes.
Regarding Claim 15, the combination of Yosh, Denso, and Li teaches the battery system of claim 9.
The “Fig. 7 – annotated for claims 6-7, 14-15”, included supra in the claim 6 section, includes detailed mapping for the two terminals of each switch and winding from Li, which are incorporated into Yosh’s cell balancing circuit.
The combo of Yosh, Denso, and Li discloses a first terminal of the third switch (SC_1, incorporated from Li) and a first terminal of the second winding wire (705, from Li).
The combo of Yosh, Denso, and Li discloses a first terminal of the fourth switch (SD_1, from Li) and a second terminal of the second winding wire (705, from Li).
The combo of Yosh, Denso, and Li discloses a second terminal of the third switch (SC_1, from Li) is connected to the second terminal of the second winding wire (705, from Li).
The combo of Yosh, Denso, and Li discloses a second terminal of the fourth switch (SD_1, from Li) is connected to the first terminal of the second winding wire (705, from Li).
Though the combo of Yosh, Denso, and Li discloses the terminals of each of the third and fourth switch, along with their connections to the second winding wire, Yosh does not disclose “a third diode connected between a first terminal of the third switch and a first terminal of the second winding wire; and a fourth diode connected between a first terminal of the fourth switch and a second terminal of the second winding wire”.
As discussed supra in the claim 14 rejection, Bada teaches “a first diode connected between a first terminal of the first switch and a first terminal of the first winding wire; and a second diode connected between a first terminal of the second switch and a second terminal of the first winding wire, a second terminal of the first switch is connected to the second terminal of the first winding wire, and a second terminal of the second switch is connected to the first terminal of the first winding wire” (see detailed mapping included supra).
Bada’s teachings are not explicitly with respect to a third diode, a third switch, a fourth diode, a fourth switch, and a second winding wire. However, because the base reference Li teaches the second winding wire (705) may be used as the input/primary winding to transfer energy to the output/secondary winding (first winding wire 704), one of ordinary skill in the art would understand that Bada’s teachings for these features are also applicable to the secondary side of Li’s converter circuit. Bada’s primary-side circuit arrangement of switches, a battery cell, and a winding are analogous to each of the primary and secondary sides of the bidirectional circuit arrangement disclosed by Li. Thus, Bada’s teachings for the arrangements of the first/second diodes can be applied to incorporate third/fourth diodes in the arrangement with the third/fourth switches and second winding wire disclosed by Li.
Bada further teaches the two diodes arranged on the input/primary side of the transformer-based converter to enable the free wheeling of current through the diodes back to the supply cell(s) in the event of damage on the secondary side of the transformer, thus protecting primary-side components by avoiding undesirable increases in voltage. (page 4, last paragraph – page 5, first paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit disclosed by the combination of Yosh, Denso, and Li to incorporate the third and fourth diodes, as taught by Bada, to protect the cell balancing circuit by preventing voltage spikes.
Thus, the combo of Yosh, Denso, Li, and Bada teaches a third diode (incorporated “D2” from Bada) connected between a first terminal of the third switch (Li: “SC_1”; Bada equivalent: “S2”) and a first terminal of the second winding wire (Li: “705”; Bada equivalent: “primary winding wire”).
The combo of Yosh, Denso, Li, and Bada further teaches a fourth diode (incorporated “D3” from Bada) connected between a first terminal of the fourth switch (Li: “SD_1”; Bada equivalent: “S1”) and a second terminal of the second winding wire (Li: “705”).
The combo of Yosh, Denso, Li, and Bada further teaches a second terminal of the third switch (Li: “SC_1”; Bada equivalent: “S2”) is connected to the second terminal of the second winding wire (Li: “705”).
The combo of Yosh, Denso, Li, and Bada further teaches a second terminal of the fourth switch (Li: “SD_1”; Bada equivalent: “S1”) is connected to the first terminal of the second winding wire (Li: “705”).
Claims 8-13 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 2011/0241622 A1) in view of Denso (DENSO Developed New Generation Battery-Monitoring Integrated Circuit for Lithium-ion Batteries, a Key component of Battery ECUs; published 08/13/2020, www.denso.com), and Bodkin et al. (US 2013/0002201 A1).
Regarding Claim 8, Li discloses a battery pack (“battery management system 700” of Fig. 7; includes some of the details shown in Figs. 12-13; see annotated Fig. 7, included supra) including a plurality of cells (“N serial coupled battery cells 702_1-702_N”; Fig. 7; ¶ [76]) connected in series.
Li further discloses a cell monitoring circuit (“monitoring circuit 1302” located within “detection and control unit 708/1208”; Figs. 7, 13) for measuring a cell voltage (¶ [128]: “1302 is configured to receive … multiple voltage detection signals indicating cell voltages of the battery cells”) of each of the plurality of cells (702_1-702_N).
Li further discloses a main control circuit (combo of “processing unit 1304” and “balancing controller 1306” located within “detection and control unit 708/1208”; Figs. 7, 13) that determines whether a deviation (Fig. 8, step 810: “V1 – V2”; ¶ [77]: “a difference between a maximal voltage and a minimal voltage among the voltages of the battery cells 702_1-702_N”; see note included infra) between a cell voltage (either “maximal voltage V1” or “minimal voltage V2”; Fig. 8; ) of a central battery cell (“battery cell 702_2”; Fig. 7; represented by voltage “V1” or “V2” when having the “minimal voltage” or “maximal voltage” per ¶ [76-80, 88]) among the plurality of cells (702_1-702_N) and a cell voltage (V1 or V2) of an outer battery cell (“battery cell 702_1”; Fig. 7; represented by voltage “V1” or “V2” when having the “minimal voltage” or “maximal voltage” per ¶ [76-80, 88]) except for the central battery cell (702_2) among the plurality of cells (702_1-702_N) is a predetermined threshold value (Fig. 8, step 810: “VTHR2”; ¶ [79, 89]: “second threshold, e.g., 50 mV”) or more (“NO” response to step 810: “V1 – V2 < VTHR2?”; Fig. 8) based on a plurality of measured cell voltages (Fig. 8, step 802; ¶ [88]: “detects voltages of multiple battery cells 702_1-702_N”).
NOTE: The example balancing operation that is most explicitly described in Li’s ¶ [87-92] is for moving charge from “702_1” with maximum voltage “V1” to “702_N” with minimum voltage “V2”. However, these are simply two cells picked out for example (¶ [88]: “e.g.”). Per ¶ [86], this circuit is configured to “balance any two cells in the battery cells 702_1-702_N”. Thus, one can interpret “V1” as representing the voltage of central battery cell “702_2” (instead of “702_1”) when it has the maximum voltage among “702_1-702_N”. Further, one can interpret “V2” as representing the voltage of outer battery cell “702_1” when it has the minimum voltage among “702_1-702_N”.
Li further discloses the main control circuit (“1304” and “1306” within “708/1208”) controls a cell balancing operation (Fig. 8) based on the determined result (result of step 810) and the charging and discharging (cell balancing is controlled based on the charging and discharging per ¶ [3]) of the battery pack (700).
Li further discloses a cell balancing circuit (combo of “transformer 703”, “first switch array 706”, and “second switch array 707”; Fig. 7).
Though Li discloses a cell monitoring circuit for measuring the cell voltages, Li does not disclose “a cell monitoring integrated circuit (IC) for measuring a cell voltage of each of the plurality of cells”.
Li further does not disclose the cell balancing circuit “prevents a first current among a charging current from flowing to the central battery cell when the deviation is greater than the predetermined threshold value in the charging condition of the battery pack, and prevents a second current among a discharging current from flowing to the central battery cell when the predetermined deviation is greater than the predetermined threshold value in the discharge condition of the battery pack”.
Denso teaches a cell monitoring integrated circuit (IC) (“new generation battery-monitoring integrated circuit”) for measuring a cell voltage (page 2, 4th paragraph: “detect battery voltage”) of each of the plurality of cells (page 2, 4th paragraph: “monitor 1.2 times more battery cells (25 ch/IC)”).
Denso further teaches a cell monitoring IC can minimize the size and cost of the hardware implementation by reducing the number of parts required to monitor the battery cells (page 3, 1st paragraph: “reduced the number of ICs and peripheral parts … to minimize the size and cost of battery ECUs”).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell monitoring circuit disclosed by Li to be an integrated circuit, as taught by Denso, to minimize the size and cost of the battery pack.
Bodkin teaches a cell balancing circuit (combo of “cell switch elements 407”, “transformer 401”, “additional balancing-charge switching element 408”, and “energy storage element 411”; Figs. 4-6) that prevents a first current (arrow “602” depicts a first current split off from charging current “603” to discharge from “high-energy cell 413B” to “adjacent secondary coil 406B” by closing “bi-directional switch 407B”; Figs. 5-6; ¶ [28]: “simultaneously taking energy from one or more high-energy cells and transfer it to one or more low energy cells”) among a charging current (current from “charger 402” to all cells is identified by arrow “603”; Fig. 6; ¶ [28]) from flowing to the central battery cell (during charging, the current to the “high-energy cell 413B” is reduced, but may occur for any of “cells 413”; Figs. 5-6) when the deviation is excessively high (¶ [9]: “higher imbalance levels”; ¶ [28]: “high-energy cell” and “low-energy cell”; see note, included infra) in the charging condition (occurs in either “balanced charging mode” or “fast charging mode”; ¶ [28, 35-36]) of the battery pack (“system 400” including “plurality of serially connected cells 413”; Fig. 4; ¶ [37-40]; Abstract: “cells making up a battery pack”).
Bodkin further teaches the cell balancing circuit (407, 401, 408) prevents a second current (¶ [32]: “the balancing-charge switch element (408) would deliver energy from the energy storage element (411) through the transformer core to the secondary windings ( 406) and through the cell switch elements ( 407) to the cells that require extra energy”; thus, the “low-energy cell 413A” delivers a smaller portion of the discharging current to “load 403”) among a discharging current (output current to “load 403”; Figs. 4-6) from flowing to the central battery cell (during discharging, the current to the “low-energy cell 413A” is reduced, but may occur for any of “cells 413”; Figs. 5-6) when the predetermined deviation is excessively high (¶ [9]: “higher imbalance levels”; ¶ [28]: “high-energy cell” and “low-energy cell”; see note, included infra) in the discharge condition (¶ [32]: “discharge balancing mode”) of the battery pack (400).
NOTE: Bodkin is not relied upon to teach the comparison of the cell-to-cell deviation with the predetermined threshold value. This comparison versus a predetermined threshold value is explicitly by Li, as discussed supra. Bodkin teaches a more generic comparison of cell voltages (¶ [9]: “higher imbalance levels”; ¶ [28]: “high-energy cell” and “low-energy cell”). One of ordinary skill in the art understands that Bodkin’s teachings for cell-to-cell rebalancing by redirecting a portion of charging/discharging currents away from a cell during charging/discharging processes is still applicable as a teaching to modify the cell balancing circuit disclosed by Li.
Bodkin further teaches to prevent the first current to the central battery cell during charging and prevent the second current during discharging to enable faster charging by balancing simultaneously with external charging (¶ [36]).
Bodkin further teaches to prevent the second current to the central battery cell during discharging to increase the capacity of the battery pack beyond the capacity of the weakest cell (¶ [9]).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the cell balancing circuit and its currents to the central battery cell when at a high cell-to-cell deviation, as disclosed by the combination of Li and Denso, to prevent the first current during charging and prevent the second current during discharging, as taught by Bodkin, for to enable faster charging of the battery pack and higher capacity of the battery pack during discharging.
Regarding Claim 9, the combination of Li, Denso, and Bodkin teaches the battery system of claim 8.
Li discloses the cell balancing circuit (703, 706, 707) includes the following features.
Li further discloses a first switch (“switch SA_2”; Fig. 7), a first winding wire (“first winding 704”; Fig. 7), and a second switch (“switch SB_2”; Fig. 7) coupled in series between both terminals of the central battery cell (“battery cell 702_2”; Fig. 7).
Li further discloses a third switch (“switch SC_1”; Fig. 7), a second winding wire (“second winding 705”; Fig. 7), and a fourth switch (“switch SD_1”; Fig. 7) coupled in series (see “Fig. 7 – annotated for series path”, included supra) between a positive electrode of a first battery cell (“battery cell 702_N”; Fig. 7) and a negative electrode of a second battery cell (“battery cell 702_1”; Fig. 7) one among the plurality of cells (702_1-702_N).
Li further discloses the first winding wire (704) and the second winding wire (705) form a transformer (“transformer 703”; Fig. 7).
Regarding Claim 10, the combination of Li, Denso, and Bodkin teaches the battery system of claim 9.
See the “Fig. 3 - annotated for claims 2-3 & 10-11”, included supra, which depicts the switching sequence for transferring charge from the central cell to the outer cell and uses the first winding wire (704) as the primary winding per ¶ [81-82].
Li further discloses the cell balancing circuit (703, 706, 707) switches the first to fourth switches (SA_2, SB_2, SC_1, SD_1) during a first period (“period T”; Fig. 3 shows all four switches change state during “period T”) in which the deviation is larger than the predetermined threshold value (“NO” response to step 810 means “V1 – V2” is ≥ “VTHR2”; Fig. 8) during the charging period (cell balancing is controlled during each of charging and discharging per ¶ [3]) to store the energy in the first winding wire (704; operating as the primary/input winding per ¶ [81-82]) by the first current (I1) and to transmit the stored energy (¶ [82]: “energy … can be transferred to and accumulated in a magnetic core of the transformer 703”; ¶ [82]: “energy stored in the magnetic core … can be released”, causing “current IN induced in the second winding 705”) in the first winding wire (704) to the second winding wire (705; operating as the secondary winding per ¶ [81-82]).
Regarding Claim 11, the combination of Li, Denso, and Bodkin teaches the battery system of claim 10.
See the “Fig. 3 - annotated for claims 2-3 & 10-11”, included supra, which depicts the switching sequence for transferring charge from the central cell to the outer cell and uses the first winding wire (704) as the primary winding per ¶ [81-82].
Li further discloses during the first period (T), the first current (I1) flows in the first winding wire (704; operating as the primary/input winding per ¶ [81-82]) during an ON period (TON) of the first and second switches (SA_2, SB_2).
Li further discloses a third current (IN; ¶ [82]: “current IN induced in the second winding 705”) is induced to the second winding wire (705) during an OFF period (TON') of the first and second switches (SA_2, SB_2; Fig. 3 shows each is off during TON') and an ON period (TON') of the third and fourth switches (SC_1, SD_1; Fig. 3 shows each is on during TON').
Regarding Claim 12, the combination of Li, Denso, and Bodkin teaches the battery system of claim 8.
See the “Fig. 3 - annotated for claims 4-5 & 12-13”, included supra, which depicts the switching sequence for transferring charge from the outer cell to the central cell and uses the second winding wire (705) as the primary winding per ¶ [83-84].
Li further discloses the cell balancing circuit (703, 706, 707) switches the first to fourth switches (SA_2, SB_2, SC_1, SD_1) during a second period (“period T”; Fig. 3 shows all four switches change state during “period T”) in which the deviation is larger than the predetermined threshold value (“NO” response to step 810 means “V1 – V2” is ≥ “VTHR2”; Fig. 8) among the discharge period (cell balancing is controlled during each of charging and discharging per ¶ [3]) to store the energy in the second winding wire (705; operating as the primary/input winding per ¶ [83-84]) and to transmit the stored energy (¶ [84]: “energy … can be transferred to and accumulated in the magnetic core of the transformer 703”; ¶ [84]: “energy stored in the magnetic core … can be released”, causing “a current IN induced in the first winding 704”) in the second winding wire (705) to the first winding wire (704; operating as the secondary winding per ¶ [83-84]).
Regarding Claim 13, the combination of Li, Denso, and Bodkin teaches the battery system of claim 12.
See the “Fig. 3 - annotated for claims 4-5 & 12-13”, included supra, which depicts the switching sequence for transferring charge from the outer cell to the central cell and uses the second winding wire (705) as the primary winding per ¶ [83-84].
Li further discloses during the second period (T), a third current (I1; ¶ [84]: “a current I1 can flow … to the second winding 705”) flows in the second winding wire (705; operating as the primary/input winding per ¶ [83-84]) during an ON period (TON) of the third and fourth switches (SC_1, SD_1).
Li further discloses the second current (IN; ¶ [84]: “current IN induced in the first winding 704”) is induced to the first winding wire (704) during an OFF period (TON') of the third and fourth switches (SC_1, SD_1; Fig. 3 shows each is off during TON') and an ON period (TON') of the first and second switches (SA_2, SB_2; Fig. 3 shows each is on during TON').
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Daniel P McFarland whose telephone number is (571)272-5952. The examiner can normally be reached Monday-Friday, 7:30 AM - 4:00 PM Eastern.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Drew Dunn can be reached at 571-272-2312. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/DANIEL P MCFARLAND/Examiner, Art Unit 2859
/JOHN T TRISCHLER/Primary Examiner, Art Unit 2859