Page 48 - CITS - Electrician - Trade Practical

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ELECTRICIAN - CITS

EXERCISE 17 : To test the battery cells with high rate

discharge tester

Objectives

At the end of this exercise you shall be able to
• check the rating of high rate cell discharge tester & battery charger
• measure the specific gravity of electrolyte and battery voltage
• test Ah rating of battery cells with high rate discharge tester
• fallow the safety precautions.

Requirements

Tools/Equipments/Instruments Materials/Components
• Combination plier (150 mm Insulated) - 1 No. • Test lead with crocodile clip
• Screw driver (100mm) - 1 No. (4.0 sq.mm) - 1 set.
• Hydrometer (1100-1300range) - 1 No. • Distilled water - 1 litre.
• Battery charger (6 -12V, 6 A) - 1 No. • Petroleum jelly - As reqd.
• Lead acid battery (12 V, 65 Ah) - 1 No. • Sand paper - As reqd.
• Digital multimeter3 digit - 1 No. • Cotton waste - As reqd.
1/2
• High rate discharge tester
(12/24 V, 50 Amp) - 1 No.

Procedure

TASK 1: Test the specific gravity & battery voltage

1 Clean the battery with wet cotton cloth & clean its terminals with sand paper.
2 Uncap the vent plugs, Check the level of electrolyte.
3 Top up the electrolyte to marked level in all cells with distilled water.
4 Check the initial specific gravity of electrolyte of each cell with hydrometer, and measure the battery voltage.
Record the measured values.
5 Connect the battery terminals tightly to battery charger with proper polarity.
6 Set the charging voltage & current in battery charger and switch ON. (Charging voltage / current value should
be as per manufactures instruction)
7 Record the initial & final charging voltage & current values.

TASK 2: Test Ah rating of battery cells with high rate discharge tester

1 Switch OFF the battery charger and disconnect battery when it is fully charged.
2 Check the specific gravity of electrolyte and battery voltage.
3 Fit the vent plugs, clean the battery surface, and apply petroleum jelly to the terminals.
4 Connect the high rate cell discharge tester to the terminals of cells of battery.
5 Note the reading, It shows the ampere-hour capacity of the cell which should be in the “Green” range when
fully charged.
6 Disconnect the cell discharge tester and similarly check other cells of battery. (Each cell should read equally)

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