TSO for maintenance of lead acid starter batteries for diesel locomotive

There have been few incidences of diesel loco failures due to various battery problems. 

1.	Problems encountered  are - 1.         Unable to restart 2.         Low battery voltage 3.         Reverse polarity 4.         Deep discharge 5.         Low specific gravity
1.1	This TSO is being issued to assist sheds to address battery maintenance related issues during initial charging of battery and trip schedule maintenance. Sheds should also refer RDSO’s instruction bulletin no. MP.IB.EC.01.06.05, Manufacturers Instruction Manual, DLW’s specification no. DEL/SPN/193, Specification For Lead Acid Starter Batteries For Diesel Locomotives & Railcars – IS:7624-1975,  Specification for Sulphuric Acid – IS:266-1961, and Specification for distilled water –  IS : 1069-1964.
2 2.1	Initial charging : Please ensure use of only battery grade sulphuric acid  (Conc) conforming to IS 266-1961.  Technical grade Acid should not be used. Incoming acid supply should be checked by lab for colour, residue on ignition (0.06% by weight,  iron percent by weight Max. .002% etc.(details given in Annexure).  Battery grade acid is colourless.
2.2	Only distilled water should be used.  Distillation plant output water should conform to IS : 1069-1964.  Parameters to be checked are (i) Non-volatile residue(less than .001 g per 100 ml),, (ii) Chlorides, (iii) Ammonia, (iv) heavy metals, (v) Calcium, (vi) Manganese, (vii) Oxidizable matter, (viii) electrical conductivity in dionic units (max. 10). (details given in Annexure 2).  Monthly sample should be sent to National / Zonal Test Houses for checking quality of water from distillation plant.
2.3	Facility for uninterrupted power supply should be provided for continuous charging.  UPS of rating 15KVA capacity with at least 30 minutes  back up should be provided. Facility to switch  on generator within 10 minutes should be developed. Two fully automated  constant current  charger  having auto restart facility on resumption of power should be used. Time counter and trip counter should be provided in MCB connected to battery charger.
2.4	Cell voltage, specific gravity & temperature should be recorded on hourly basis.
2.5	Cell temperature should be kept below 450c by suitably regulating charging current (below 2.6V)
2.6	No cell having temperature variation more than 20C, low cell voltage and low specific gravity should be permitted.
2.7	Cell charging is complete when cell voltage and specific gravity  value remains constant for 3 consecutive hourly reading at the end of charging period & cell  voltage of 2.6 - 2.7 Volts  is achieved. Improper initial charging is the root cause of low specific gravity in cells.
3.	C10 capacity test : Once charging is complete, battery should be discharged through suitable resistance at a constant current ( 0.1 x C10) amperes and the discharge shall be stopped when cell voltage falls down to 1.70 volt. Capacity in ampere shall be obtained by multiplying the discharge current by the total time of discharge in hours. New batteries must give 450 AH / 500 AH capacity as per battery type.  New battery must be capable of withstanding at least 10 cranking cycles.
4.	Check point during initial charging : If any cell is not picking up  voltage aboe 2.55V during initial charging even after complete duration of charging, those  batteries have to be kept aside  for investigation by supplier.  Those batteries should not be loaded to loco.
5.	Trip maintenance : Parameters to be noted during every schedule when locomotive touches  the shed. 1.         Individual cell voltage 2.         Individual cell gravity. 3.         Water consumption 4.         Temperature of cells, battery leads during cranking. 5.         Physical battery condition. 6.         Individual cell voltage during cranking. 7.         Individual cell special gravity during cranking.
5,1	Exception list should be prepared and batteries having low specific gravity, low voltage and higher water consumption should be identified and removed from service. An average battery should not consume more than 2-2.5 lts. of water per month.  Any battery consuming more water indicates high evaporation loss due to excessive cell temperature.
5.2	Higher temperature rise form battery leads or cells during cranking is sign of imminent battery damage.
5.3	If cell voltage falls below 1.9V then battery should not be recharged simply.  It should be first discharged as per C10 and then it  should be put on charging.
6.	Battery life ; Properly maintained battery can easily give minimum 4 years service in  main line loco services  and additional 2 years service can be taken in inferior services.
6.1	Petroleum jelly and zinc coated fastener should be used for terminal connection.
6.2	Calibrated beaker for topping up of water should be used for measuring exact amount of water topped up.
6.3	Whenever loco is stabled dead in shed for more than 1 day, in situ trickle charging should be done.
6.4	Batteries should be removed and taken to section during M24 and above for attention and charging. Shulphated cells having low cell voltage if left uncharged are unable to undergo reversible reaction during charging and subsequently cells become dead Deep discharging below 1.7V should not be done.
6.5	No topping up of acid should be done during schedule checking as only water evaporates so DM / distilled water should be topped up.
6.6	Proper lifting device as per sketch given in annexure should be used
7.	Check point  during  trip maintenance : Initial cranking  current is very high i.e. 2300A & sustained cranking current is 1400A./  So all cell abnormalities will be highlighted during cranking. Defective cells will exhibit lower cell voltage, high cell temperature & lower specific gravity.
7.1	Ampere hour capacity test at 10 hr. rate  (C10 test)should be conducted and any battery having less than 80% capacity should be discarded
8. Instruction for battery revival: Condition Symptom Action Desired Final value Partial sulphation Low cell voltage 1.8 – 2.0V Low sp. Gravity < 1220 1.Slow rate charging i.e. 5% of C10. 2. If  gravity after charging is more, them mix with DM water & charge for  2 hrs Cell voltage 2.6-2.7V Sp. Gravity 1250 Heavy sulphation Dead Cell Low cell voltage < 1.8V     Sp. gravity    < 1210 1.Pour out electrolyte from cell. 2.Fill cell with DM water 3.Charge cell with 5% of C10 rate.  4.Dump originally filled distilled water & fill with final gravity acid recommended at the end of full charge.  5.Change the battery with normal charging rate until the voltage reached to 2.6 to 2.7V per cell. Cell voltage 2.6V Sp. Gravity 1250
9.	Record keeping : Records are to be maintained by battery section as per Performa given in Annexure. Root cause analysis to be done as per format enclosed. Cells removed from locos before four years of service should be jointly investigated with battery manufacturers. Warranty claim should be lodged in case of failures within 24 months of service.

       DA: As stated

                                                                             

ANNEXURE

Format for Exception List

a)    Low specific gravity

Loco No. & date	Specific gravity								Remarks
	1L	2L	3L	4L	1R	2R	3R	4R

b)    Low cell voltage

SL No	Loco no.	Date	Cell voltage								Remarks
			1L	2L	3L	4L	1R	2R	3R	4R

c)    Trip wise Water  consumption

SL No	Loco no.	Date	Water consumption								Remarks
			1L	2L	3L	4L	1R	2R	3R	4R

d)    High water consumption

Loco no.	Water consumption		Battery identified for removal.	Remarks
	One month	Four month