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ELECTRICAL
8
Leaving Battery Idle
Causes the battery to run down due to
self-discharge. The lead sulphate crystals
formed as a result of self-discharge grow as the
battery stands idle and are not easily converted
back on recharge. The Sulphation in other words
tends to become permanent thus affecting
battery capacity and lowering battery life.
High Specific gravity
It is destructive for both positive and
negative plates to separator and shortens battery
life.
2. LACK OF WATER
Impure topping –up water
Impure water or electrolyte introduces
impurities into the battery, which accumulate
with each such topping – up.
The most common impurities are iron and
chlorine, which attack plates and shorten
overall life.
This will result in higher water loss and
premature failure.
Neglecting topping-up
De-mineralized water (
DM
) water or
distilled water is one of the four essential
chemicals of a lead acid battery and under
normal conditions of operation the only
component of the battery, which is lost as the
result of charging. It should be replaced as soon
as the liquid level falls to the top of the separator.
If water is not replaced plates will soon be
exposed and the acid will reach a dangerously
high concentration that may oxidize the
separator. It further can permanently impair the
performance of the plates. Plates cannot play full
part in the battery reactions unless they are
completely covered by the electrolyte. Acid
should not be added to cells.
3. INSTALLATION:
Loose Hold –downs
Container damages arise from gross
mishandling or dropping batteries, from hold-
downs either over tightened or extremely
loose. This may physically damage the plates
and separators in cells or cause leakage of
electrolyte so that the battery becomes
unserviceable.
Excessive loads
A battery should never be used to propel
the car by the use of the starter motor with clutch
engaged except in a great emergency. This may
produce extremely high internal battery
temperature and may also damage the starter
motor.
4. OPERATIONAL PROBLEMS
Discharge without recharge
A fully discharged or near fully discharged
cell will be damaged and possibly ruined if not
recharged within 24 to 48 hours. As a battery
discharges, the electrolyte starts changing from
an acid solution to almost pure water. Lead
dissolves in water and some of the plate material
mixes with water to form lead hydrate. Lead
hydrate causes the plate surfaces to turn white
and, because it is conductive it forms a short
circuit between the plates rendering the battery
permanently damaged.
Over discharge
Over
discharge
causes
abnormal
expansions of the active materials in the plates
which leads to permanent damage and also
recharge problems.
BATTERY TESTING
Battery testing has two basic elements
1.Visual Inspection
2.State of Charge
a.Specific Gravity
b.Open Circuit Voltage
1. VISUAL INSPECTION
Battery service should begin with a thorough
visual inspection. This inspection may reveal
simple, easily correctable problems.
Check for cracks in the battery container and
broken terminals. Either may allow electrolyte
leakage and warrant battery replacement.
Check for broken cable or connectors. Replace
as needed.
Check for corrosion on terminals and dirt or
acid on the battery top. Clean the terminals –
and battery top with a mixture of water and
baking soda. A battery wire brush tool is
required to remove hard scales if any on the
terminals.