Exide Technologies Section 93.10 - Manual (Page 10)

7
SECTION 8
8.0 Initial Charge
Batteries lose some charge during shipment as well as during
the storage period prior to installation. The battery should be
installed and given its initial charge as soon after receipt as
possible. At the completion of initial charge, record voltage
and specific gravity of each cell while still on charge and retain
records for future reference per Section 14.0.
8.1 Constant Voltage Method
Constant voltage is the principal method to give the initial
charge, as most modern chargers are of the constant volt-
age design. In addition, some systems have equipment with
voltage limitations making the use of constant current charg-
ing undesirable.
Determine the maximum voltage that may be applied to the
system equipment. The voltage divided by the number of
cells connected in series will establish the maximum voltage
per cell that may be used.
Establish whether the battery is of lead-antimony or lead-
calcium construction by referring to type on cell name plate
and compare this with the proper GNB sales literature.
For lead-antimony types, refer to Table A and for lead-calci-
um types refer to Table B to obtain various voltages and
associated time periods recommended. Select the highest
voltage the system will allow, to perform the initial charge in
the shortest period of time.
The recommended time periods are considered minimum.
Raise the voltage to the maximum value permitted by the
system equipment. When charging current has tapered and
stabilized (no further reduction for 3 hours), charge for the
hours shown in the appropriate table and for the battery tem-
perature, at the time of stabilization, until the lowest cell volt-
age ceases to rise. Monitoring of cell voltages should be
started during the latter 10% of the applicable time period to
determine lowest cell in battery.
INITIAL CHARGE
Recommended Voltages and Time Periods
TABLE A
Lead-Antimony Types
NOTE: Time Periods listed in tables A and B are for cell
temperatures from 70°F (21°C) to 90°F (32°C). For temper-
atures 55°F (13°C) to 69°F (20.5°C) double the number of
hours. For temperatures 40°F (4°C) to 54°F (12°C) use four
times the number of hours.
TABLE B
Lead-Calcium Types
8.2 Initial Charge — Electrolyte Levels
During the initial charge, there will be an increase in the
electrolyte levels and they may go above the high level mark.
(See Section 3.2). This is due to gases, that were lost during
transportation or standing in storage, being restored to the
cells.
Do not remove any electrolyte even though levels
may be above high level. When battery is placed on floating
charge (See Section 9.2). the electrolyte levels should return
close to the high level line.
Removal of electrolyte during the initial charge with subse-
quent restoration with water of levels which have fallen fol-
lowing placement on float charge mode could result in vari-
ations or sub-normal specific gravity values.
SECTION 9
9.0 Operation
9.1 Floating Charge Method
In this type of operation, the battery is connected in parallel
with a constant voltage charger and the critical load circuits.
The charger should be capable of maintaining the required
constant voltage at battery terminals and also supply a nor-
mal connected load were applicable. This will then sustain
the battery in a fully charged condition and also make it
available to assume the emergency power requirements, in
the event of an AC power interruption or charger failure.
9.2 Float Charge — Float Voltages
The following are the float voltage ranges recommended for
the various types of batteries. Select any “volts per cell”
value within the range listed that will result in the series
string having an average volts per cell equal to that value.
Do not interchange voltage ranges from one type to another.
Time-Hrs. Time-Hrs. Time-Hrs.
1.215 1.250 1.300
Cell Volts sp. gr. sp. gr. sp. gr.
2.24 444 — —
2.27 333 — —
2.30 210 — —
2.33 148 333 —
2.36 100 235 400
2.39 67 160 267
2.42 48 108 182
2.45 38 73 125
2.48 36 55 83
2.50 32 44 60
Time-Hrs. Time-Hrs
1.215 1.250
Cell Volts sp. gr. sp. gr.
2.24 200 —
2.27 150 —
2.30 120 —
2.33 90 146
2.36 75 129
2.39 60 97
2.42 — 73
2.45 — 54
2.49 — 36
2.50 — 30