Page 42
www.enersys.com Publication No. US-FL-IOM-002 January 2007
12.6 Filling
and
Charging Moist-charged Cells
Cells may be received moist-charged. This type of cell should be activated (filled with electrolyte
and charged) only when ready to be placed in service. Moist-charged cells are active and
contain charge. DO NOT SHORT THE TERMINAL POSTS. Moist-charged cells may be stored
for up to five years without deterioration in cool, low-humidity locations (<90
o
F, <50%H).
To activate the cells, remove and discard the pressure-relief valves and fill the cells to the low
level line with an approved grade electrolyte. Mix the electrolyte before use to eliminate
stratification.
NOTE:
The filling electrolyte specific gravity must be 15 points (.015)
less than the cell nominal specific gravity.
When mixing electrolyte, always add acid to water. Pour slowly and stir constantly, to avoid
excessive heat or violent chemical reaction.
Allow the battery to stand for four hours after filling. Add additional sulfuric acid of the filling
electrolyte specific gravity to bring the electrolyte level up to the low level line. The charge must
be started within 12 hours of the initial fill.
Before charging, install the flame arrestors, and then lock in place with one quarter turn
clockwise. Then install the dust cap, when provided, on each arrestor.
The preferable way to charge antimony alloy cells is a constant voltage averaging 2.50 volts per
cell. For calcium alloy cells, the voltage needs to be 2.70 volts per cell. Charge for the time
shown in Table 8.1 after current stabilization.
Methods to accomplish such initial charging are:
•
Parallel the battery to reduce the effective number of cells by half when the charger
voltage can be reduced significantly to achieve the volts per cell specified above, or
•
Charge 80% of the cells on system charger, and use an auxiliary charger to charge the
remaining cells, or
•
Charge about 80% of the cells from the positive end, using the maximum voltage
indicated previously. Then reconnect about 80% of the cells from the negative end,
and using maximum voltage indicated, charge until the remaining 20% of the cells that
were not charged the first time are fully charged. Do not be concerned if 60% of the
cells obtain twice the normal charge; however, they may require some additional
water.
If cell temperatures exceed 110
o
F (43
o
C), interrupt the charge and wait until the
temperature has dropped to 100
o
F (38
o
C). Then the charging may be resumed.
Summary of Contents for PowerSafe Data Safe
Page 8: ......
