Battery Operating and Maintenance

BATTERY OPERATION AND MAINTENANCE

I)   1.   (a) The Ampere hour capacity of 220V batteries at smaller Sub-stations shall

be 80.

            (b) The same at EHT Sub-stations shall be 200

(c) Batteries with 300Amps hour capacity shall be used only at Power houses or Sub- stations where solenoid closing of circuit breakers is in use.

2.      The trickle charging rate shall be

            “Amp hour capacity x 2/24x100 plus regular discharge in amps”.

3.      The boost charge rate shall not exceed “ Amp.hour capacity divided by ten”.

4.      The individual cell voltage shall not go down below 2.1 volt.

5.      The specific gravity should not differ by more than 30 points between cells in the same battery maximum and minimum. Where the difference is more; electrolyte should be diluted by adding distilled water in cells with higher specific gravity thus narrowing down the difference and all cells in the battery given a boost charge.

Under no circumstances electrolyte or concentrated acid should be added to cells with low specific gravity.

6.      Usage of alkali cells and acid cells in the same substation should be avoided to avert inadvertent mix up of electrolyte or usage of accessories of one with the other.

7.      Leakage indication lamps should be compulsorily connected on the charges panel for continuous indication of healthiness.

8.      Every D.C. Circuit takes off should be through protective fuses (H.R.C) or m.c.bs.

9.         (i) Once in a day A.C. supply to charges should be switched off and D.C.   voltage measured and noted.

(ii) In that condition with no A.C. supply to charger, the duty performance of the battery by closing or tripping of a relatively un-important breaker is to be ensured. Mere availability of D.C voltage is no index of healthiness of battery.

            (iii) A.C supply to charger is to be restored immediately after this test.

10.  Certain charger panels have “Switch Off” arrangement whenever A.C supply fails. There should be switched on after each restoration of supply.

11.  Leakages in D.C circuitry should be attended on top priority first by sectionalisation, then by isolation and finally be rectification.

Lead Acid Batteries (Common)

1.      Check up the Electricity to level in the cell of all the cells in morning shift every day. If the electrolyte is low, top up the cell with distilled water.

2.      Check up the voltage and specific gravity of six cells in each shift and record as per cell numbers given (PILOT CELLS)

3.      Check up the D.C voltage of the combined cells (battery) after switching off the battery charger every day in the morning shift. Record the battery voltage and current with the charger off.

4.      Ensure that the battery is in floating condition normally by adjusting the rheostat of the charger.

5.      Never charge a battery at a voltage higher than 2.4 V per cell i.e., it works out to 264 V for 220 V Battery and limit the charger ampere capacity also.

6.      If any of the cells is found to be having low voltage and specific gravity, by pass the cell. The removed cell should be charged separately and replaced after the voltage and specific gravity attains normal value. Improvement should not be attempted by adding acid to electrolyte.

7.      Check the condition of all the cells every month for voltage and specific gravity. Charge the battery if required. The voltage and specific gravity readings shall be taken before and after charging. The charging rate shall be limited to 10 hours rating to avoid excessive gassing and evaporation of Electrolyte.

8.      All the cells shall be physically checked for fracture and buckling of the container and excessive rise. Check battery terminals for tightness. Apply Vaseline (petroleum jelly) whenever necessary. This check should be attempted after the battery is brought to full charge.

9.      Keep the charger off, observe the voltage with D.C lighting ‘on’ continuously for two hours. Observe the voltage and current. The voltage should not fall by 10% when the discharge on the battery is at 10Hrs i.e., 25Amps for 250Hrs. battery 30Amps for 300Hrs. battery etc. Every discharge shall be compensated by charging. As the ampere hour efficiency is always less than unity, the charging ampere hours shall be more than discharge ampere hours.

The battery charger panels, in some cases have a no volt trips. Whenever A/C supply fails, the charger should be switched on after restoration of AC supply.