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4.4.9 The rating assigned to the cell or battery is the capacity expressed in ampere-hours
(after correction to 27 degrees C) stated by the manufacturer to be obtainable when the cell or
battery is discharged at the 10 Hr. rate to the end voltage of 1.80 V per cell.
4.5 MAINTENANCE :
The present and most efficient procedure for the maintenance of lead acid cells is to
carry out through overhauls, repairs, rigid tests and quality control during POH work of TL /
AC coaches in the workshops. The work in the maintenance depots is confined only to
regular and systematic examination, occasional topping up of cells and charging whenever
needed.
4.5.1 Train lighting batteries of coaches by the very nature of service conditions cannot
be expected to have steady rate of charge/discharge. They are often left to idle for long
duration or charged at higher rates. Such strenuous service of these cells therefore calls for
systematic and thorough examination while in service, prompt remedial measures of
defects/replacement of cells and quality POH work in Shops to achieve the expected life
without any loss of efficiency below 80 %.
4.5.2 Running maintenance of storage batteries falls under four categories :-
1. Trip examination,
2. Fortnightly examination,
3. Quarterly examination,
4. Intermediate overhaul.
4.5.3 Trip Examination :
To know the condition of cells during 'Trip Examination' some cells in a battery are
treated as 'Pilot' cells. On arrival of train in the maintenance line, disconnection shall be done
at inter vehicle connections, Recording of the specific gravity of' ‘Pilot’ cells in each battery
shall be done, Pilot cells in coaches should be changed every month and. Marking of Pilot
cells should be made as described. Cells are usually provided either in 2 battery boxes of 6
cells each or 1 battery box of 12 cells in coaches with DC-.24 V system. Cell number for
marking pilot cells should be reckoned from left to right while facing the battery box. On
receipt of coach from POH, the 1st and 12th cells should be marked 'P' in chalk indicating as
Pilot cells. This should be changed to 2nd and 11 th after a month, 3rd and 10th in the next
month, and so on in the subsequent months. After the cycle is completed, the same cycle
should be repeated. The idea of changing the Pilot cells is to ensure that true condition of the
battery is reflected, till the cells are sent for next POH and to take prompt remedial action in
case of defects. In case of conventional coaches working on DC 110 V system there are two
boxes with 28 cells in each. Marking of these cells to indicate Pilot cells shall be done as
follows:-
GENERAL SERVICES : TRAIN LIGHTING 47