Samlex America SCC-30AB - Manuel (Page 27)

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4
PRINCIPLE OF OPERATION & FEATuREs
the Float Voltage Regulation Set Point “Vf” continuously for around 1 hour, the
controller reverts to Stage 1: Bulk Stage. PWM DUTY Cycle is changed to 100% and
the LCD Screen 4 (Fig 5.3) changes to “State: Bulk”.
Equalization Charging
General Information on Equalization
Caution!
• Equalization is carried out only for non-sealed / vented / flooded / wet cell Lead
Acid batteries.
• Do not equalize sealed / VRLA type of AGM / Gel Cell batteries unless permitted by
the battery manufacturer
• Top up the electrolyte with distilled water after completion of equalization.
• Excessive overcharging and gassing too vigorously can damage the battery plates and
cause shedding of active material from the plates. An equalization that is too high
or for too long can be damaging. Review the requirements for the particular battery
being used in your system.
• There should be no load on the batteries and there should be full bright sun for the
entire day (no shade or clouds) to ensure that maximum available current from the
panels can be used to equalize the batteries.
• The Short Circuit Current of the panels should be at least 5% to 10% of the Ah
capacity of the battery bank
Equalization is intentional overcharging of the battery for controlled period of time.
Routine equalization cycles are often vital to the performance and life of a battery —
particularly in a solar system where peak sun hours per day are limited and variable
and may not be sufficient to keep the battery in a fully charged condition. Periodic
Equalization is carried out for proper health and long life of a Lead Acid battery to
prevent / reduce the following undesirable effects:
Sulfation: If the charging process is not complete due to the inability of the charger
to provide the required voltage levels or if the battery is left uncharged for a long
duration of time, the soft Lead Sulfate crystals on the Positive and Negative plates
that are formed during discharging / self discharge are not fully converted back to
Lead Dioxide on the Positive plate and Sponge Lead on the Negative plate and get
hardened and are difficult to dislodge through normal charging. These crystals are
non-conducting and hence, introduce increased internal resistance in the battery. This
increased internal resistance introduces internal voltage drop during charging and
discharging. Voltage drop during charging results in overheating and undercharging