ABSTRACT
This chapter introduces storage batteries for conventional engine-based vehicles, rated at either 14 Vdc or 28 Vdc. The type of storage battery most used in automotive applications is a lead–acid cell-type battery. The specific density of the electrolyte is measured with a hydrometer. This device makes use of Archimedes’ principle: a solid suspended in a fluid is buoyed by a force equal to the weight of the fluid displaced. The battery voltage test is used on maintenance-free batteries because these batteries do not have caps that can be removed for testing with a hydrometer. The capacity of a battery is measured in Ampere–hours and its rating is required by law in Europe, under the EU Battery Directive 2006/66/EC. Modern electronic chargers are able to precisely control a constant charging current through power management and electronic power converters, connected from the grid to the battery. The sole storage source of electrical energy within an auto vehicle consists of a battery.
