Chevrolet 1977 light duty truck, Руководство по обслуживанию

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NEGATIVE
SEPARATOR
ELEMENT
2 VOLT BATTERY CELL
C O N T A IN E R ELECTROLYTE
Fig. 6 D - 3 B -B a tte ry E le m e n t (S im ple)
cover is bonded to the case forming an air-tight seal between
the cover and case.
Electrical energy is released by chemical reactions
between the active materials in the two dissimilar plates and
the electrolyte whenever the battery is being "discharged."
M axim um electrical energy is released only when the cells
are being discharged from a state of full charge.
As the cells discharge, chemical changes in the active
m aterials in the plates gradually reduce the potential
electrical energy available. "Recharging" the battery with a
flow of direct current opposite to that during discharge
reverses the chemical changes within the cells and restores
them to their active condition and a state o f full charge.
The lead-acid storage battery is an electrochemical
device for converting chemical energy into electrical energy.
It is not a storage tank for electricity as is often believed, but
instead, stores electrical energy in chemical form.
Active m aterials within the battery react chemically to
produce a flow of direct current whenever lights, radio,
cranking m otor, or other current consuming devices are
connected to the battery term inal posts. This current is
produced by chemical reaction between the active materials
of
the PLA TES and the sulfuric acid of the
ELECTRO LY TE.
The battery performs three functions in automotive
applications:
1. It supplies electrical energy for the cranking m otor
and for the ignition system as the engine is started.
2. It supplies current for the lights, radio, heater, and
other accessories when the electrical demands of these devices
exceed the output of the generator.
3. The battery acts as a voltage stabilizer in the electrical
system. Satisfactory operation of the vehicle is impossible
unless the battery perform s each of these functions.
The simplest unit o f a lead-acid storage battery is made
up of two unlike m aterials, a positive plate and a negative
plate, kept apart by a porous separator. This assembly is
called an "E L E M E N T " (Fig. 6D-3B).
W hen this simple element is put in a container filled with
a sulphuric acid and water solution called "electrolyte", a
Fig. 6 D -4 B ~ T w o V o lt B a tte ry Cell
two-volt "cell" is formed. Electricity will flow when the plates
are connected to an electrical load (Fig. 6D-4B).
An element made by grouping several positive plates
together and several negative plates together with separators
between them also generates two-volts but can produce more
total electrical energy than a simple cell (Fig. 6D-5B).
W hen six cells are connected in series, a "battery" of
cells is formed which produces six times as much electrical
pressure as a simple cell, or a total o f 12 volts (Fig. 6D-6B).
If the battery continuously supplies current, it becomes
run-down or discharged. This is where the generator gets into
the act. The generator restores the chemical energy to the
battery. This is done by sending current through the battery
in a direction opposite to that during discharge. The
generator current reverses the chemical actions in the battery
and restores it to a charged condition.
2 VOLTS