Journal of Applied Electrochemistry

, Volume 9, Issue 3, pp 369–379

Impedance parameters and the state-of-charge. II. Lead-acid battery

  • M. L. Gopikanth
  • S. Sathyanarayana
Papers

DOI: 10.1007/BF01112492

Cite this article as:
Gopikanth, M.L. & Sathyanarayana, S. J Appl Electrochem (1979) 9: 369. doi:10.1007/BF01112492

Abstract

The determination of the state-of-charge of the lead-acid battery has been examined from the viewpoint of internal impedance. It is shown that the impedance is controlled by charge transfer and to a smaller extent by diffusion processes in the frequency range 15–100 Hz. The equivalent series/parallel capacitance as well as the a.c. phase-shift show a parabolic dependence upon the state-of-charge, with a maximum or minimum at 50% charge. These results are explained on the basis of a uniform transmission-line analog equivalent circuit for the battery electrodes.

Nomenclature

Battery

This word is used synonymous with the word ‘cell’

Rp

equivalent parallel resistance (Ω)

Rs

equivalent series resistance (Ω)

¦Z¦

modulus of impedance (Ω)

Cp

equivalent parallel capacitance (F)

Cs

equivalent series capacitance (F)

φ

a.c. phase-shift (radians or degrees)

ω

2πf

f

a.c. frequency (Hz)

RΩ

resistance of electrolyte solution and separator (Ω)

¯C

double layer capacity (F)

W

diffusional (Warburg) impedance (Ω)

Rt

resistance due to polarization (Ω)

α

energy transfer coefficient

T

absolute temperature (K)

R

gas constant

F

Faraday constant

CO0

bulk concentration of the oxidant

CR0

bulk concentration of the reductant

DO

diffusion coefficient of the oxidant

DR

diffusion coefficient of the reductant

σ

Warburg coefficient

N

number of pores/area

A

active area of the electrode (cm2)

S

state-of-charge

a

anode

c

cathode

L

inductance

Io

exchange current

Copyright information

© Chapman and Hall Ltd. 1979

Authors and Affiliations

  • M. L. Gopikanth
    • 1
  • S. Sathyanarayana
    • 1
  1. 1.Department of Inorganic and Physical ChemistryIndian Institute of ScienceBangaloreIndia