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Current Imbalance in Parallel Battery Strings Measured Using a Hall‐Effect Sensor Array
Author(s) -
Luca Robert,
Whiteley Michael,
Neville Toby,
Tranter Tom,
Weaving Julia,
Marco James,
Shearing Paul R.,
Brett Dan J. L.
Publication year - 2021
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.202001014
Subject(s) - battery (electricity) , string (physics) , electrical engineering , series and parallel circuits , current (fluid) , power (physics) , computer science , electronics , automotive industry , materials science , optoelectronics , voltage , acoustics , engineering , physics , aerospace engineering , quantum mechanics
Herein, individual cell currents in parallel connected battery strings are measured using micro‐Hall‐effect sensors. Cells are routinely connected in electrical series and parallel to meet the power and energy requirements of automotive and consumer electronics applications. Cells connected in series have been extensively studied; however, cells in parallel are often assumed to be a “black box” in battery management systems. Poor pack design can result in positive feedback between current and temperature differentials along the parallel string, driving greater levels of heterogeneous behavior and uneven degradation. Herein, a noninvasive multisensor array board using Hall‐effect sensors is used to individually record the current passing through eight parallel connected cells in two different electrical configurations, showing highly heterogeneous current distribution. Characteristic “waves” of current and temperature are found to propagate along the parallel battery string and cell rebalancing is found to occur over hundreds of seconds with individual cell currents of up to 1 C rate.