Variables that influence results of impedance testing for valve regulated cells

This paper demonstrates the effects of two variables that influence measured internal cell impedance values: state-of-charge and temperature. Both influences have an inverse effect in that the internal impedance will decrease as the cell is subjected to proper float charging and/or elevated temperatures. The popularity of this test technique has been propelled since the advent of the sealed valve-regulated lead acid cell, and an understanding of the data that must be collected to correlate the findings must be attained. Data presented represents tests on valve-regulated cells of both gelled and absorbed electrolyte technology.>