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3.0 CHARGING
Charging incorrectly leads to the majority of battery problems so it is very important that these charging instructions be followed.
Contact SBS should you have any questions related to battery charging.
Over/Under Charging
Over charging within reasonable limits will not damage a nickel-cadmium battery, but water consumption will be increased.
A Ni-Cd battery can be left standing for short periods at any state of charge without damage.
Charging Current
Limitation of the charging current is not required under floating condition.
During the initial or an equalize charge, the current should be limited to:
Flooded
Ni-Cd
batteries:
.2
C
5
= 20% of the 5hr Ah rating of the battery
Valve Regulated Ni-Cd batteries:
.1
C
5
= 10% of the 5hr Ah rating of the battery*
Example:
KPM100P = 100 Ah flooded Ni-Cd battery. The maximum charge current is (20%) 0.2 x 100Ah = 20 Amps. If there is a
constant load of 2.5 Amps on the system, add 2.5 to the maximum charger current limit: 20 + 2.5 =22.5 Amp current limit setting.
*VRPP Charging Current Warning! Using a current higher than 10% of the batteries 5 hour Ah rating will make the VRPP batteries
gas more than the recombination vent cap can handle. This will cause increased electro-chemical activity in the cell, which may
lead to electrolyte ooze out or ‘boil over’.
Initial / Commissioning Charge
Before initial charge, all batteries must be inspected for physical and/or mechanical damage. Make sure that the batteries electrolyte
levels are above the <Min> line. Do not adjust the VRPP electrolyte levels at any time however.
Equalize charge the system for 72hours at a voltage of:
Flooded Pocket Plate Ni-Cd batteries:
1.54-1.69 Vpc
Valve Regulated Pocket Plate Ni-Cd batteries:
1.45 Vpc
Flooded Fibre Plate Ni-Cd batteries:
1.52-1.57 Vpc
If after 72 hours any cells have a voltage of 1.36 Volts or less the system may need to be charged for longer or at a higher voltage.
Upon completion of the initial charge place the batteries on float charge and record the following initial reference values. This data
should be kept and stored with future test data for warranty purposes.
Date and time of the completion of the initial charge on the battery system
All individual cell voltages
Float voltage of the DC output of the charger as measured on the main (+) and (-) terminals of the battery.
Float current of the DC output of the charger measured on the cable(s) to the positive post of the battery.
Float AC ripple voltage and current as measured on the main (+) and (-) terminals of the battery.
Electrolyte temperature of every 10
th
cell
Top off all electrolyte levels after battery has been on float charge for a minimum of 24 hours.
Float Charge
When in service batteries should be maintained on float charge and should be fully recharged within 24 hours of any discharge.
There are two options for float charging SBS ni-cd batteries:
Float Option A: System will require a boost charge every 3-6 months
Flooded
Ni-Cd
batteries:
1.40-1.42
Vpc
Valve Regulated Ni-Cd batteries:
1.40-1.42 Vpc
Float Option B: Periodic boost charge NOT required however user may have to add water to the system more frequently
Flooded
Ni-Cd
batteries:
1.46-1.50
Vpc
Valve Regulated Ni-Cd batteries:
Not Advisable
Float voltage should not vary by more than +/-1%.
Should the float voltage of any cell drop below 1.36 Volts apply a 72 hour boost charge to the system or the individual cell.
