Lesson 2/Learning Event 2
Learning Event 2:
DESCRIBE MAINTENANCE PROCEDURES FOR AUTOMOTIVE BATTERIES
In nearly all cases of early failure of automotive batteries, the cause can be traced to a lack of
preventive maintenance. When given proper care, batteries generally will give no trouble until they
are worn out, unless damaged by accident or enemy action. The vehicle operator and the
organizational level mechanic are responsible for performing preventive maintenance on the
batteries of vehicles assigned to the unit.
Each time the vehicle is started and often during its operation, the driver should check the battery-
generator indicator located on the dash panel. The battery-generator indicator on tactical vehicles is
a meter that shows the level of battery voltage. It has a scale marked off in three colors: red,
yellow or amber, and green.
When the ignition switch is first turned on, the indicator hand will usually point to the yellow
section, which is the center part of the scale. If the hand points to the red at the left side of the
scale, the battery is in a low state of charge. (The hand may point to the green scale on the right if
the battery was just recently charged at a high rate.)
If the battery charge is low, find out the cause and make necessary corrections. If a battery is
allowed to remain in a low state of charge for very long, the sulfate formed in the plates will
harden, and it will be impossible or very difficult to return the battery to a fully charged condition.
When the engine is started, the battery-generator indicator hand will move to the right if the
charging system is operating properly. The hand will point to the left half of the green part of the
scale when the battery is fully charged.
If the hand moves into the right half of the green scale, the battery is being overcharged. (On
some indicators this part of the scale is red instead of green.) The operator should have the
charging system checked immediately before the battery or charging system is damaged.
Overcharging overheats the battery, causing it to lose water at a fast rate, and can warp the plates
causing permanent damage.