Page 454 - Battery Reference Book

Introduction 4413
Two principal methods of battery charging are used; ies). Another proposal, which has been tried out for
constant-potentiad charging and constant-current char- charge control of sealed nickel-cadmium cells, is to
ging. Many variants of these methods exist, such as incorporate an oxygen-consuming auxiliary electrode
the float charge regimen and the shallow charge regi- in the cell to consume oxygen gas as it is evolved
men, which are modifications of the constant-potential towards the end of charge and on overcharge and thus
method. Also, mmy methods of control of the charging prevent the build-up of excessive internal gas pres-
process exist. These include charging for a particular sure. This, however, needs extensive modifications of
time to a particular end-voltage, charging to a par- the cell structure and consequently is expensive and
ticular end-current, charging controlled by electrolyte increases the overall cost. The various methods used
temperature, and charging controlled by the internal to charge different types of battery by these methods
pressure of the battery (in the case of sealed batter- are discussed in Chapters 45-49.