Charging Stages - Samlexpower SEC-1260A Owner's Manual

CHARGING STAGES

Stage 1
I Phase
U
o
U
80% of current
capacity of charger
Time, Hours
NOTE: Voltage reading on no load. The output terminals of the charger consist of one
common white / black negative terminal (3) and two red positive terminals (1, 2) for charging
two banks of batteries. Each of the two positive terminals of the two banks has a Schottky
Diode in series for isolation. These isolating diodes have a current dependent forward voltage
drop ranging from 0.2 to 0.3 V (at 0.1 A) to 0.6 V (at 40 - 80 A). Please note that the forward
voltage drop occurs only when current flows through the diode.
The Float and Absorption voltages are tightly regulated before the isolating diodes. How-
ever, the voltages available at the terminals of the two banks will vary with the value of the
charging current because of the current dependent forward voltage drop across the isolating
diodes. The Float and Boost / Absorption voltages before the diodes are, therefore, set 0.2 to
0.3 V higher to compensate for the above forward drop during float condition when the
charging current would have dropped to less than 1 A. Hence, the output voltage at the
terminals of the two banks at no load (nothing connected to the terminals of the banks) will
read 0.2 to 0.3 V higher because there is no forward voltage drop as there is no current flow
through the diodes.
Please also note that the output voltage at the two banks may differ between 0.2 to 0.6 V
depending upon the different values of the charging current being delivered through each.
Stage 2
Uo Phase
Timed for 4/8
Hours
10% of current
capacity of charger
Fig 4. Charging Curve
Page 11
Stage 3
U Phase
Curve for
Voltage U, U
o
Curve for
Current, I