GEAR & WEIGHT AS 1317125 - Caterpillar

Introduction to Battery
The battery stores energy for the complete electrical system. The battery produces current upon demand for the machine electrical devices.Batteries
Illustration 1 g01072957
A battery stores electrical energy in chemical form to be released as electrical energy for the machine electrical system. This includes the starting, charging, and accessory circuits. This battery current is produced by a chemical reaction between the active materials of the battery plates and the sulfuric acid in the electrolyte. The battery is a voltage stabilizer for the system. The battery acts as an accumulator or a reservoir of power.After a period of use, the battery becomes discharged and will no longer produce a flow of current. The battery can be recharged with direct current, in the opposite direction that current flows out of the battery. In normal operation, the battery is kept charged by current input from the alternator.For good operation, the battery must do the following:
Supply current for starting the engine.
Supply current when the demand exceeds the output of the charging system.
Stabilize the voltage in the system during operation.Battery Construction
A battery is made up of a number of individual elements in a hard rubber case or plastic case. The basic units of each cell are positive and negative plates, as shown in Illustration 1. Negative plates have a lead surface, which is gray in color, while the positive plates have a lead peroxide surface which is brown in color. The negative plates and positive plates are connected into plate groups. In some batteries, there is always one more plate in the negative group than in the positive group. This allows the negative plates to form two outsides when the groups are interconnected. Other batteries have the same number of positive plates and negative plates.Each plate in the interlaced group is kept apart from a neighbor by porous separators, which allow a free flow of electrolyte around the active plates. The complete assembly is called an element. Elements in different cells are connected in series in order to increase voltage. The cells are separate from one another, so there is no flow of electrolyte between the cells. Each cell will produce approximately 2.2 volts. So if 6 cells are connected together in series, the battery will produce approximately 13.2 volts.
Illustration 2 g01072958
The electrolyte in a fully charged battery is a concentrated solution of sulfuric acid in water. The electrolyte has a specific gravity of about 1.270 at 27 °C (80 °F), which means the electrolyte weighs 1.270 times more than water. The solution is about 36% sulfuric acid H2SO4 and 64% water H20.Battery Water
The necessity for pure water in batteries has always been a controversial subject. It is true that water with impurities affects the life and performance of a battery. Whether or not the effect of impure water is truly significant will depend on how high the mineral content of your water supply is. Generally, you do not have to use distilled water rather than tap water, but it will be better for the