Samplex Europe SEC-1245E, Owner'S Manual

Page: 12 / 39

C
u
rr
e
n
t,
I
V
o
lt
a
g
e
,
V
80% of current
ca p acit y of char ger
10% of current
ca p acit y of char ger
Time, Hours
Stage 1
I Phase
Stage 2
Uo Phase
Timed for 4/8
Hours
Stage 3
U Phase
U
o
U
Curve for
Volta ge U, U
o
Curve for
Current, I
CHARGING STAGES
Fig 4. Charging Curve
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 voltagedrop 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.
However, 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 thecharging current wouldhave 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.
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