Samsung SDI proposes battery diagnostics based on individual cells' balancing time. US application US20260299045A1, published on October 1, 2026, measures how long each cell participates in balancing. The accumulated times are intended to indicate unusual behaviour.
Balancing time as a diagnostic measurement
Balancing reduces differences in voltage or state of charge between cells. The method measures the duration for each cell and adds it across multiple operations. A processor compares the accumulated times with a criterion, for example based on the pack's mean and standard deviation. If a time exceeds an upper limit or falls below a lower one, the system can classify the cell as unusual. Depending on the deviation, proposed responses include a warning, a charging limit or stopping use. The approach evaluates an operating measurement; it does not describe an AI model.
The original document covers measurement, accumulation and diagnosis in independent claim 1. Claim 7 adds the mean-based criterion; paragraphs [0057]–[0064] explain the statistics. Figure 6 is a conceptual example.
Unusual does not necessarily mean damaged
The document provides no experimentally demonstrated detection rate or false-alarm rate. Its thresholds are examples. Unusual balancing time alone does not establish a particular cell defect. Reliability across different charging conditions and differently aged cells would require practical testing. The publication establishes neither production use nor prevented fires or longer battery life.
Document and status
“Method and Apparatus for Identifying an Abnormal Battery Cell”: Applicant Samsung SDI Co., Ltd.; US application 19/412,436, filed December 8, 2025; claimed Korean priority KR 10-2025-0038682 dated March 26, 2025. A1 denotes a published application, not a grant. We could not independently confirm the current official prosecution status on October 3, 2026.
Pandorex View: Balancing operations that already take place could yield an additional diagnostic signal. The decisive question is whether the time statistics distinguish actual faults from normal cell differences without unnecessarily taking usable batteries out of service.