Page 197 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

3 Positive Plate: Terminal or Post Strap The post or terminal with which the positive plates are internally
connected is called the positive terminal or positive post. The + positive plate is soldered on it.
4 Cell Compartment Cover: Each compartment has cells. To cover them, a compartment cover is put on the
cell. Under this cover, there is a place for the cell, and on the top, one negative terminal and one positive
terminal per cell are seen coming out. In the middle of this, there are one or two filler or vent plug holes on
which the vent plugs are tightened.
5 Cell Connector or Link Connector: Since the cells of the battery are installed in series, the positive terminal
of one cell is connected with the negative terminal of the other cell. This work is done by the cell connector.
6 Sealing Compound: A special type of mixture (sealing compound) is applied to join the compartment cover
of the cells with the battery body so that the battery electrolyte does not jump out due to shock.
7 Negative Terminal or Negative Post: All the negative plates inside the cell will be connected to the negative
post.
8 Negative Plate Strap: Negative strap is used to keep the plates together like a shoulder.
9 Sediment Space or Element Rest: Sediment space is provided inside the battery case so that the debris
or other dust particles etc. from the plates settle down. Element rest or ribs are made to keep the cell plate
assembly on top and the space in between is left for the debris.
10 Negative Plate: It is connected to the negative strap at the top, its grid is filled with spongy metallic lead and
its Colour is grey.

11 Separator: To prevent short circuit between the negative and positive plates of the battery cell, a separator
made of special wood fiber, rubber and glass fiber mats etc. is used. It should be porous so that the solution
can pass through it.
12 Positive Plate: Like above, it is connected to the positive terminal by its positive strap. Its grid is filled with red
peroxide (PbO2) of chocolate brown ring.
13 Grid: It is made by mixing antimony and lead and is cast in a rectangular/lattice shape. It does not get
damaged in chemical reaction.
14 Cell: A cell is formed by having one positive plate, one separator on each side of it and then negative plates
on both sides. Instead of using positive plate and big negative plates, the number of small plates has been
increased in the cell to get more active area. Because the active paste acts on both the sides of the positive
plate, hence there is one more negative plate.
15 Electrolyte: The plates of the battery are immersed in a solution of sulphuric acid in their respective cell
containers. The specific gravity of this solution is 1.250 to 1.280. The appropriate solution for the battery is
also available readymade, otherwise it is prepared. Pure sulphuric acid and distilled water are used to make it.
It should be made in a glass, porcelain or plastic container and it should be kept in mind that the acid should
be poured into water, because if water is poured into the acid, its splashes will burn the body or clothes. This
solution should be filled up to about 15 mm above the plates of the battery.

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CITS : Automotive - Mechanic Diesel - Lesson 57 - 61