Page 210 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

Electrolyte Specific Gravity: The charged or discharged state of the battery can be determined by measuring
the specific gravity of the electrolyte in the battery cell. Spa. Hydrometer is used to measure gravity. Figure no in
hydrometer. there is a glass tube and a rubber ball (ball) is placed at the top to create suction in the tube and draw
the electrolyte. A fine hose is attached to the underside of the tube.

A glass tube contains a floating float on the top of which a paper strip with specific gravity numbers is attached. To
check the gravity of the electrolyte in the cell, when the electrolyte in the cell is suctioned in the hydrometer, the
float in the hydrometer starts floating and becomes more or less submerged in the electrolyte depending on the
specific gravity of the electrolyte. The number at which the float on the level of the electrolyte in the tube is stable
is the specific gravity of that electrolyte. 1.300 to 1.230 spe to indicate the state of full charge at the lowest point
on the paper strip on the hydrometer float. Gr. There is a yellow bar with a limit of up to 1.230 to 1.160 spec to
indicate the half charged state of the battery. Gr. Mayadi has a white stripe up to 1.140 to 1.100 spec to indicate
the discharge state of the battery.

Temperature effect on specific gravity
Temperature has an impact on the specific gravity of substances, such as liquids like water. Usually, when
temperature rises, the density of most substances decreases, leading to a decrease in their specific gravity.
However, this change might not be consistent for all substances. In the case of water, it reaches its highest
density at approximately 4 degrees Celsius (39.2 degrees Fahrenheit). When the temperature moves away from
this point, the density of water alters, influencing its specific gravity. Hence, when determining specific gravity, it’s
crucial to account for the temperature during the measurement and make adjustments if needed.
Battery troubles and their remedies

Battery troubles
1 Self-Discharging.
2 Sulphation
3 Internal Short Circuiting.

4 Deterioration of Plates.
5 Cracking of Container.
6 Corrosion of Battery Terminals and Clamps.

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CITS : Automotive - Mechanic Diesel - Lesson 57 - 61