A Balancing Current Ratio based State-of-Health Estimation Solution for Lithium-ion Battery Pack

Xiaopeng Tang, Furong Gao, Kailong Liu, Qi Liu, Aoife M. Foley

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)
422 Downloads (Pure)


The inevitable battery ageing is a bottleneck that hinders the advancement of battery-based energy storage systems. Developing a reliable health assessment strategy for battery pack is important but challenging when the joint requirements of computational burden, modelling cost, estimation accuracy, and battery equalisation are considered. This paper proposes a balancing current ratio (BCR)-based solution to realise satisfactory state-of-health (SoH) estimation performance of all series-connected cells within a pack, while the overall reliance on cell-level battery models is also reduced. Specifically, after employing BCR to describe the properties of the balancing process, the voltage-based active balancing is combined into the SoH estimator design for the first time, leading to a weighted fusion strategy for effectively estimating SoHs of all cells within a pack. Hardware-in-the-loop experiments show that even if a parameter-fixed open-circuit-voltage-resistance (OCV-R) model is adopted, the typical estimation error of our proposed solution can still be bounded within only 1.5%, which is 70% lower than that of the benchmarking algorithms. Due to the model-free nature of the integrated voltage-based balancing, the robustness and flexibility of the proposed pack SoH estimation solution are also improved.

Original languageEnglish
JournalIEEE Transactions on Industrial Electronics
Early online date03 Sept 2021
Publication statusEarly online date - 03 Sept 2021

Bibliographical note

Publisher Copyright:

Copyright 2021 Elsevier B.V., All rights reserved.


  • Aging
  • Balancing current ratio
  • Batteries
  • Battery charge measurement
  • Computational modeling
  • Current measurement
  • Electric Vehicle
  • Estimation
  • Lithium-ion Battery Pack
  • Sensors
  • State-of-health Estimation

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering


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