22
Rev.12/31/97
years. Lead-selenium cells have a longer life expectation than lead-calcium
or lead-antimony. A battery is considered worn out when it fails to deliver
80 percent of its original capacity.
or lead-antimony. A battery is considered worn out when it fails to deliver
80 percent of its original capacity.
2.21 CLEANLINESS
2.21 CLEANLINESS
Battery connections must be clean, bright, and free of corrosion for the
battery to perform. Corrosion that is not cleaned off terminals periodically
will spread into areas between posts and connectors. This condition will
develop into a high resistance connection and cause heating and wasted
capacity. The battery and surrounding parts should be kept clean, dry, and
free of acid. Sulfuric acid absorbs moisture, and spilled electrolyte will not
dry up. If electrolyte is spilled or sprayed out of the cells on charge,
neutralize with a solution of baking soda (1 pound of soda to 1 gallon of
water), then rinse with distilled water and dry with a soft cloth.
battery to perform. Corrosion that is not cleaned off terminals periodically
will spread into areas between posts and connectors. This condition will
develop into a high resistance connection and cause heating and wasted
capacity. The battery and surrounding parts should be kept clean, dry, and
free of acid. Sulfuric acid absorbs moisture, and spilled electrolyte will not
dry up. If electrolyte is spilled or sprayed out of the cells on charge,
neutralize with a solution of baking soda (1 pound of soda to 1 gallon of
water), then rinse with distilled water and dry with a soft cloth.
A labeled jar
of soda solution at least one gallon, must be kept in the battery room. Care should be
taken to prevent the solution from getting into the cells. Make sure vent
plugs are open, flame arresters and dust caps are in place, and all
components are in good condition.
components are in good condition.
2.22 INTERNAL SHORTS
2.22 INTERNAL SHORTS
A short circuit through a separator may be caused by:
1. Insufficient charging causes material in the plates to become mostly lead
sulfate. The lead sulfate expands and, if the grid does not crack to relieve
the strain, the plate will become distorted. This condition is commonly
known as buckling. The buckling is most pronounced at the four corners
of the positive plates, where shorts are most likely to occur.
the strain, the plate will become distorted. This condition is commonly
known as buckling. The buckling is most pronounced at the four corners
of the positive plates, where shorts are most likely to occur.
2. Impurities in the solution caused by using contaminated water or dirty
utensils.
3. Excessive overcharging causes the grid specific gravity to be partially
converted to lead peroxide, which reduces mechanical strength and
allows positive and negative plate contact.
allows positive and negative plate contact.
A short in a cell can be detected by falling specific gravity and falling cell
voltage. In some cases, an orange discoloration occurs at the point of the
short. If a short is long standing, disintegration of the positive plate will
occur at the point of contact with the negative because of the conversion of
positive plate material to negative.
voltage. In some cases, an orange discoloration occurs at the point of the
short. If a short is long standing, disintegration of the positive plate will
occur at the point of contact with the negative because of the conversion of
positive plate material to negative.
2.23 NORMAL SULFATE AND OVER SULFATION
2.23 NORMAL SULFATE AND OVER SULFATION
During discharge of a battery, "normal" sulfate is formed, which is required
to produce current. If charging is neglected, the sulfate fills the pores of the
plates and makes the active material dense and hard. This condition is
referred to as "over sulfated."
to produce current. If charging is neglected, the sulfate fills the pores of the
plates and makes the active material dense and hard. This condition is
referred to as "over sulfated."