Active SOC Balancing for a Multi-Chemistry Battery Pack with Reduced Number of Converters: Preprint

Alastair Thurlbeck, Ashraf Siddiquee, Mithat Kisacikoglu, Yilmaz Sozer

Research output: Contribution to conferencePaper


In energy storage systems using second-life or multi-chemistry cells, an active state of charge (SOC) balancing system can prolong pack life and enhance performance by utilizing the healthier cells more than those which are heavily degraded. However, the high cost of the active balancing system, particularly in converter-based solutions, prevents their widespread usage. Considering this, existing research has proposed numerous balancing systems utilizing only one converter. However, such systems may compromise the balancing speed too much. Therefore, this work proposes two active balancing systems with a reduced number of converters for 14-16 series-connected cells. One system uses two converters for direct cell-to-cell balancing. The other uses a time-multiplexed approach to exchange energy via an auxiliary low-voltage (LV) bus using four converters. The proposed balancing systems are compared to two baseline systems, a single converter cell-to-cell balancing system, and a 14 converter balancing system with an auxiliary LV bus.
Original languageAmerican English
Number of pages11
StatePublished - 2023
EventIEEE Energy Conversion Congress & Expo (ECCE) - Nashville, TN
Duration: 29 Oct 20232 Nov 2023


ConferenceIEEE Energy Conversion Congress & Expo (ECCE)
CityNashville, TN

Bibliographical note

See NREL/CP-5400-88819 for paper as published in proceedings

NREL Publication Number

  • NREL/CP-5400-86749


  • battery pack
  • converters
  • dual active bridge
  • energy storage
  • Kalman filtering
  • SOC balancing


Dive into the research topics of 'Active SOC Balancing for a Multi-Chemistry Battery Pack with Reduced Number of Converters: Preprint'. Together they form a unique fingerprint.

Cite this