Alpha Technologies Industrial Ni-Cd Batteries Standard Range - Manual (Page 28)

28 EN-ALPHA-TMSR-001 (10/09)
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7.5. Periodic Maintenance, continued
7.5.2 Electrolyte check and topping up
Check the electrolyte level and never let the level fall below the lower level mark "MIN". Use only distilled
or deionized water to top-up the cells in accordance with IEC 60993. Experience will tell the time interval
between topping-up. Refi lling with electrolyte is only permissible if spilled electrolyte has to be replaced. If
during refi lling or topping up electrolyte has been splashed onto the cell cover or between the cell cases clean
this off and then dry the area. NOTE: Once the battery has been fi lled with the correct electrolyte either at
the factory or during the battery commissioning, there is no need to check the electrolyte density periodically.
Interpretation of density measurements is diffi cult and could lead to misunderstandings.
7.5.3 Replacing of electrolyte
In most stationary applications the electrolyte will retain its effectiveness for the total lifetime of the battery.
However, under special battery operating conditions, if the electrolyte is found to be car- bonated, the battery
performance can be restored by replacing the electrolyte. Only use genuine electrolyte. It is recommended to
change the electrolyte when reaching a carbonate content of 75 g/litre. It is possible to test the electrolyte in
the works laboratory. For this a minimum quantity of 0.2 litres of electrolyte in a clean glass or polyethylene
container should be sent in, paying strict attention to the valid dangerous goods regulations. Expediently the
sample of electrolyte is taken half an hour after charging has ended and from several cells of the battery. It
is pointless to take the samples immediately after topping up. The electrolyte sample and the cells should
be closed immediately after the electrolyte has been taken. CAUTION - caustic potash solution is corrosive!
Safety regulations shall be applied, goggles and gloves shall be used.
7.5.4 Electrolyte temperature
The temperature of the electrolyte should never exceed 45 °C as higher temperatures have a detrimental
effect on the function and duration of the cells. In the course of charging an electrolyte temperature of = 35 °C
should be aimed for. On exceeding 45 °C the charging should be temporarily interrupted until the electrolyte
temperature falls down to 35 °C. The temperature measurements are to be made on one of the cells in the
middle of the battery. Low ambient or electrolyte temperatures down to -25 °C do not have any detrimental
effect on the battery; they just cause a temporary reduction in capacity.
7.0 Installation and Operation, continued