Prosecution Insights
Last updated: April 19, 2026
Application No. 17/944,894

BATTERY LIFE EXTENSION METHOD

Non-Final OA §103
Filed
Sep 14, 2022
Examiner
SILVA, FRANK ALEXIS
Art Unit
2859
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Trend Power Technology(changshu) Inc.
OA Round
3 (Non-Final)
34%
Grant Probability
At Risk
3-4
OA Rounds
3y 7m
To Grant
97%
With Interview

Examiner Intelligence

Grants only 34% of cases
34%
Career Allow Rate
10 granted / 29 resolved
-33.5% vs TC avg
Strong +63% interview lift
Without
With
+62.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
53 currently pending
Career history
82
Total Applications
across all art units

Statute-Specific Performance

§101
9.5%
-30.5% vs TC avg
§103
59.9%
+19.9% vs TC avg
§102
20.3%
-19.7% vs TC avg
§112
7.8%
-32.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 29 resolved cases

Office Action

§103
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 . Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 02/25/2026 has been entered. Status of the Claims In the communication filed on 01/20/2026 claims 1-5 are pending. Claim 1 is amended by rewriting limitations and incorporating new limitations not presented before. Claims 6-9 are cancelled. Response to Arguments/Amendments Applicant's arguments and amendments filed 01/20/2026 have been fully considered but they are not persuasive. First, the applicant in page 7 of the Remarks dated 01/20/2026 argues that claim 1 has been expressly limited to operation after the battery pack has been fully charged and set in a stationary state. In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., “without any transition to or from a charging state”) are not recited in the rejected claim. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). If the prior art is capable of performing the function claimed, then it meets the claim. Second, the applicant in page 7 of the Remarks dated 01/20/2026 argues that the cited prior art Zhang fails to teach balance operations as claimed since Zhang teaches that balance operations are performed during charging or external discharging rather that in a stationary state. However, the examiner respectfully disagrees. The examiner cites ¶[54] and ¶[283] of Zhang which explicitly state that the system continues monitoring voltages after it is fully charged because the circuit module determines full charge based on single-cell voltages and the monitoring unit continuously acquires state parameters including full-pack and single-cell voltages. Taking into consideration MPEP 2144.04 V. E. Making Continuous, it would have been obvious to one of ordinary skill in the art to have extended Zhang into cases wherein the battery is in a fully charged state since these balancing operations are performed during charging/discharging. Third, the applicant in page 8 of the Remarks dated 01/20/2026 argues that the cited prior art Yoshida addresses balance operations for preventing premature termination of an external discharge rather than in a stationary state. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). The remaining arguments are moot as the applicant’s arguments for the remaining claims were based on dependency of the independent claims. Drawings The drawings are objected to because step S450 in Fig. 2 includes spelling mistakes which would need to be corrected, see annotated Fig. 2 below. PNG media_image1.png 331 558 media_image1.png Greyscale Corrected drawing sheets in compliance with 37 CFR 1.121(d) 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 Claim 1 is objected to because of the following informalities: in line 21 add --pack-- after “battery” in order to avoid a lack of antecedent basis issue. Claim 5 is objected to because of the following informalities: in line 4 add --plurality of-- before “batteries” in order to avoid a lack of antecedent basis issue. Claim 5 is objected to because of the following informalities: in line 8 add --pack-- after “battery” in order to avoid a lack of antecedent basis issue. For examination purposes, these limitations will be interpreted as “battery pack” and “plurality of batteries”, however, appropriate correction is required. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1 and 3-5 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al. (USPGPN 20250141238), and further in view of Yoshida (WIPO Patent WO-2016098631-A1). With respect to claim 1, Zhang teaches a battery life extension method (In ¶ [75] a mode of operation is taught wherein prolongs the life of the battery pack). Zhang teaches after a battery pack consisting of a plurality of batteries connected in series is determined to have been fully charged and set in a stationary state, continuously detecting a voltage of each of the plurality of batteries (In Figs. 2-11 the monitoring unit 118 detects in real-time the individual voltages of the series-connected batteries 150 in the battery pack, see ¶ [283]. In ¶ [54] by monitoring the voltages of the series-connected batteries it may be determined that the battery pack has been fully charged in which one of ordinary skill understands would set the battery pack into a stationary state). Zhang teaches determining a first difference of the battery pack, and a second difference for each of the plurality of batteries, wherein the first difference corresponds to a difference between a highest voltage and a lowest voltage among the plurality of batteries, and the second difference corresponds to a difference between a voltage of the battery and the lowest voltage among the plurality of batteries (In ¶ [213] a first difference between the maximum voltage value and the minimum voltage value according to the acquired individual voltages among the plurality of batteries is determined. In ¶ [220] a second difference between the actual voltage of each of the plurality of batteries and the minimum voltage value is determined). Zhang teaches selectively performing at least one of a balance operation based on the continuously detected voltages of each of the plurality of batteries in the stationary state (¶[54]; taking into consideration MPEP 2144.04 V. E. Making Continuous (see below), it would have been obvious to one of ordinary skill in the art to have extended Zhang into cases wherein the battery is in a fully charged state since these balancing operations are performed during charging/discharging). Zhang teaches when the first difference is greater than the first predetermined voltage difference and the lowest voltage is greater than a balance starting voltage, the balance operation is performed until either all of the second differences become smaller than a second predetermined voltage difference or the lowest voltage becomes smaller than the balance starting voltage (In ¶ [220-221] teaches when the voltage difference between the highest and lowest battery cells (i.e., first difference) is above a preset threshold, and the lowest voltage is still above a minimum level, a balancing operation is started and continues until all the voltage differences between each cell and the lowest voltage (i.e., second differences) fall below a smaller preset value). Zhang teaches the second predetermined voltage difference is smaller than the first predetermined voltage difference (In ¶ [220-221] a second preset difference is 30 mV and a third preset difference is 10 mV. It is understood by one of ordinary skill a first preset difference would be larger since the first difference is between the max cell voltage – min cell voltage, the second difference is between each cell voltage – min voltage, and the third difference is between the target cell voltage – min voltage thus first preset > second preset > third preset). However, Zhang fails to explicitly teach when the first difference is smaller than a first predetermined voltage difference and the lowest voltage is greater than a discharge starting voltage, the discharge operation is performed until the lowest voltage becomes smaller than the discharge starting voltage; and the discharge starting voltage is greater than the balance starting voltage. Yoshida teaches when the first difference is smaller than a first predetermined voltage difference and the lowest voltage is greater than a discharge starting voltage, the discharge operation is performed until the lowest voltage becomes smaller than the discharge starting voltage (In Figs. 2-3 a discharging operation is performed until the balance operation conditions are met in step S110 when the maximum voltage and minimum voltage difference is greater than a difference threshold in step S202 and when the minimum voltage among the battery cells is below a predetermined reference voltage VB). While Yoshida initiates discharging when the voltage difference is large and the minimum cell voltage is already low approaching the discharge end voltage, it would have been obvious for one of ordinary skill to have modified the battery pack of Zhang with the discharging operation of Yoshida to initiate discharging when the minimum voltage is still above the cutoff voltage. The benefit of this modification being extending the battery life thereby decreasing operational and maintenance (O&M) costs. However, Zhang fails to explicitly teach the discharge starting voltage is greater than the balance starting voltage. While Yoshida teaches initiating discharging when the minimum voltage approaches a low reference threshold and Zhang teaches balancing based on preset voltage differences, it would have been obvious to one of ordinary skill to set a discharge starting voltage greater than the balance starting voltage when combining the teachings. The benefit to this modification being to clearly distinguish when to perform a discharging operation versus when to start a balance operation thereby providing a logical way to manage battery safety and efficiency depending on the imbalance. MPEP 2144.04 V. E. Making Continuous In re Dilnot, 319 F.2d 188, 138 USPQ 248 (CCPA 1963) (Claim directed to a method of producing a cementitious structure wherein a stable air foam is introduced into a slurry of cementitious material differed from the prior art only in requiring the addition of the foam to be continuous. The court held the claimed continuous operation would have been obvious in light of the batch process of the prior art.). With respect to claim 3, Zhang teaches the invention as discussed above in claim 1. Further, Zhang teaches further comprising an act of terminating the discharge operation or the balance operation if the battery pack is determined in charging or in discharging during the discharge operation or the balance operation (In ¶ [213-214, 218] teach terminating a discharge or balance operation when charging or discharging is detected when fault conditions including voltage imbalance are detected). With respect to claim 4, Zhang teaches the invention as discussed above in claim 1. Further, Zhang teaches wherein each of the plurality of batteries is connected in parallel with a balance resistor through a switch, and the discharge operation comprises turning ON all the switches to make the plurality of batteries discharge through the paralleled-connected balance resistors (In ¶ [222] teaches that each battery core is connected to a bleeder unit comprising a switch and a resistor in parallel, and during discharge, the control module closes the bleeder switch to allow the target battery core to discharge through the resistor). With respect to claim 5, Zhang teaches the invention as discussed above in claim 1. Further, Zhang teaches wherein each of the plurality of batteries is connected in parallel with a balance resistor through a switch, and the balance operation comprises turning ON the switches connected in parallel with the batteries having the second differences greater than the first predetermined voltage difference to discharge through the parallel-connected balance resistors, and continuously detecting whether each of the second differences is smaller than the second predetermined voltage difference; and turning OFF all the switches connected in parallel with the battery when any second difference of the plurality of batteries is smaller than the second predetermined voltage difference (In ¶ [221-222] teach that each battery core is connected in parallel with a bleeder resistor and switch, and during balancing, the control module identifies the target battery cores (i.e., those with voltages exceeding the second preset difference from the minimum), turns on their respective bleeder switches to discharge them, and continuously detects voltages to determine when to stop discharging by turning off the switches when voltage difference fall below the present threshold). Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al. (USPGPN 20250141238), in view of Yoshida (WIPO Patent WO-2016098631-A1), and further in view of Wang et al. (USPGPN 20200049772). With respect to claim 2, Zhang teaches the invention as discussed above in claim 1. However, Zhang fails to explicitly teach wherein the determination of the battery pack consisted of the plurality of batteries that has been fully charged and set in the stationary state comprises a holding time period of a total voltage or an average voltage of the battery pack that has been fully charged and set in the stationary state is greater than a determined time period. Wang teaches wherein the determination of the battery pack consisted of the plurality of batteries that has been fully charged and set in the stationary state comprises a holding time period of a total voltage or an average voltage of the battery pack that has been fully charged and set in the stationary state is greater than a determined time period (In ¶ [22, 26, and 41] teach determining when a battery pack has reached a stationary state after charging by requiring the voltage to stabilize over a sufficient holding period). Therefore, it would have been obvious for one of ordinary skill to have modified the battery pack of Zhang with the relaxation time (i.e., stationary state) determination method of Wang in order to require a total or average value to remain above a threshold for a sufficient holding time period. The advantage to this modification being that open circuit voltage used for estimation is accurate thereby improving battery life management and preventing error due to making estimates based on a sufficiently relaxed cell voltage (see ¶ [45] of Wang). Relevant Prior Art The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Watanabe et al. (USPGPN 20150318721) teaches a voltage balance control device selects a reference capacity battery cell on the basis of battery capacity and calculates a balance target voltage value according to the capacity difference between the reference capacity battery cell and each battery cell. The balance target voltage value is calculated such that the remaining charge capacity at a charging end time of an assembled battery and the remaining discharge capacity at a discharging end time thereof either should substantially match each other or should be at a predetermined ratio. Even if the voltage characteristic of each battery cell changes after performing voltage balancing, this makes it possible to set the minimum capacity battery cell as a charging and discharging end voltage limiting cell and fully use the capacity of the minimum capacity battery cell to bring out the maximum battery performance of the assembled battery. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Frank A Silva whose telephone number is (703)756-1698. The examiner can normally be reached Monday - Friday 09:30 am -06:30 pm ET. 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. /FRANK ALEXIS SILVA/Examiner, Art Unit 2859 /DREW A DUNN/Supervisory Patent Examiner, Art Unit 2859
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Prosecution Timeline

Sep 14, 2022
Application Filed
May 14, 2025
Non-Final Rejection — §103
Aug 27, 2025
Response Filed
Nov 15, 2025
Final Rejection — §103
Jan 20, 2026
Response after Non-Final Action
Feb 05, 2026
Examiner Interview (Telephonic)
Feb 09, 2026
Examiner Interview Summary
Feb 25, 2026
Request for Continued Examination
Mar 04, 2026
Response after Non-Final Action
Mar 12, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
34%
Grant Probability
97%
With Interview (+62.8%)
3y 7m
Median Time to Grant
High
PTA Risk
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