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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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