Charging Stages & Protections; Bulk Charge Stage - Samlexpower SeC-1215UL Owner's Manual

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1. VOLTAGE READINGS ON NO LOAD
The output has one common Negative terminal and three Positive terminals for charg-
ing 3 banks of batteries. Each Positive terminal has an internal isolating diode in series
which has a forward voltage drop of 0.8 to 1.1 V. On no load (that is when no battery
or other DC load is connected to any of the 3 terminals) , the voltage reading will
read 0.8 to 1.1 V higher than the specified float voltage. Note that the specified float
voltage is at a load of 1 A. Also, the voltage on the terminals not connected to the
load (for example, when one bank of battery is connected to one Positive terminal,
the other 2 Positive terminals will remain disconnected) will read 0.8 to 1.1 Volt higher
than the voltage of the loaded terminal.
2. VOLTAGE SPECIFICATIONS
All rated voltages are specified at battery temperature of 80°F.
These chargers can be manually selected
to operate in 3 stage or 2 stage modes
(Please see "Selecting the type of Battery
and charging Stages" at page 11) . The
charging stages are described below:
Stage 1 - constant current or

Bulk charge Stage

When the battery is low, it will try to
draw larger charging current. The charger
senses the current draw and limits this
to the maximum permissible value (15A
for SEC-1215UL / SEC-2415UL and 30A for
SEC-1230UL). Bulk charging takes place at
this constant current. in this condition of
constant current, the voltage measured
at the charger or battery terminals will be
the battery's own voltage.
The constant current injected into the
battery starts restoring the battery capac-
ity and it's voltage starts rising. When
this voltage approaches the threshold
of battery "gassing", termed "Boost or
Absorption Voltage", the charger auto-
matically switches over to Stage 2 - "Boost
or Absorption Stage". The value of this
voltage depends upon the type of battery
being charged (See DIP Switch Settings).
By this time, approximately 80% of the
battery capacity will normally have been
8 | SAMLEX AMERICA INC.
Charging states & Protections
restored (note: The percentage capac-
ity restored till the point the battery
reaches the Boost or Absorption Voltage is
inversely proportional to the value of the
bulk charge current.)
Stage 2 - constant Voltage Boost
or Absorption Stage
As explained above, when the battery
voltage approaches the point where
battery "gassing" can begin, the charger
automatically switches over to the "Boost
or Absorption Stage". The charger applies
a constant voltage whose value depends
upon the type of battery selected (See DIP
Switch Settings). This controlled over-
charge restores the balance 20% of the
capacity in a minimum amount of time. As
the capacity is fully restored, the charging
current starts reducing. When the current
reduces below the preset threshold, the
charger automatically switches to the
"Float or Maintenance Stage".
Stage 3 - constant Voltage , Float
or Maintenance charging Stage
As explained above, as the charging cur-
rent drops below the preset threshold
(1.5 to 2 amps for SEC-1215UL / SEC-2415UL
and 2.5 A to 3 A for SEC-1230UL), it signals
that the battery is 100% charged.