Section 4: Principles Of Operation - SamplexPower SEC-1250UL Guide D'utilisation

SECTION 4 |
i
INFO
For complete understanding of working of battery chargers, understanding of
operation of Lead Acid batteries is desirable.
For detailed information on construction, working and application of batteries,
please refer to White Paper titled "Batteries, Chargers and Alternators" at the
following link to Samlex America, Inc. website:
www.samlexamerica.com/support/whitepapers.aspx
4.1 SWITCH MODE POWER SUPPLY (SMPS) CHARGER
This unit is a Switched Mode Power Supply (SMPS) and charger that converts 120 / 230
VAC, 50 / 60 Hz to regulated DC voltages and limits the maximum output current equal
to the rated Bulk Stage Current (Current Limit Value) as shown in Table 4.1.
TABLE 4.1 CHARGING STAGE VOLTAGES AND CURRENTS
Model No.
SEC-1250UL
SEC-2425UL
The specified output voltage of the charger during particular charging stage is held
constant till the Bulk Stage Current value is reached. When the battery or DC load tries
to draw current > the Bulk Stage Current value (50A for SEC-1250UL & 25A for SEC-
2425UL), the charger limits the current to the Bulk Stage Current value and the output
voltage of the charger drops and is no longer constant. When the charger is charging a
battery at current = the Bulk Stage Current, it will be in current limit condition and the
terminal voltage of the charger will drop but will be clamped to the actual lower intrin-
sic terminal voltage of the battery relative to its Stage of Charge at that time.
8 | SAMLEX AMERICA INC.
Principles of Operation
Bulk Stage
Current Constant
(Current Voltage in
Limit Value) Bulk Stage
50A 13.5 VDC
25A 27 VDC
Constant Constant
Voltage in Voltage
Absorption in Float
Stage Stage
14.0 VDC or
13.5 VDC
14.4 VDC
28 .0 VDC
27 VDC
or 28.8 VDC
Terminal
Voltage at
No Load
(See Table 4.2)
13.7V to
13.8V
27.2V to
27.3V