Equalization requirements for series VRLA batteries

P. T. Krein, S. West, C. Papenfuss

Research output: Contribution to conferencePaperpeer-review


State-of-charge (SOC) balance is a necessary task in any high-rate series battery system. This equalization task is evaluated here through cycling and hybrid vehicle platform tests of valve-regulated lead-acid (VRLA) batteries. It is shown that when voltage matching is used as the basis for SOC equalization, voltage differences must be kept small. An upper limit of 15 mV/cell was found from the tests, although a limit of 10 mV/cell is more realistic for a practical system. A diffusion model is developed for voltage-based equalization processes. A switched-capacitor equalization approach introduced previously is shown to be a low-cost way to meet the accuracy requirements while allowing the charge diffusion process to be accelerated. The tests show that switched-capacitor equalization supports lifetime extension in series strings.

Original languageEnglish (US)
Number of pages6
StatePublished - Jan 1 2001
Event16th Annual Battery Conference on Applications and Advances - Long Beach, CL, United States
Duration: Jan 9 2001Jan 12 2001


Other16th Annual Battery Conference on Applications and Advances
CountryUnited States
CityLong Beach, CL

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Equalization requirements for series VRLA batteries'. Together they form a unique fingerprint.

Cite this