Battery Charging With Sitop Psu300B - Siemens PSU300B Manual

Applications

9.7 Battery charging with SITOP PSU300B

9.7 Battery charging with SITOP PSU300B
The SITOP PSU300B power supplies are optimized for charging lead accumulators. For a U-
I characteristic curve set to parallel operation (DIP switch "A" at "ON", see Section Figure 2-6
Selector switch (example 6EP1456-3BA00 / 6EP1437-3BA20) (Page 15)), the battery to be
charged is charged with a constant current until approximately 95% of the set SITOP output
voltage is reached (set using a potentiometer, see Section Figure 2-4 Potentiometer
(example 6EP1456-3BA00 / 6EP1437-3BA20) (Page 11)). The charging current then
decreases continuously from 1.2 × rated current at 95% of the set voltage to approx. 0 A or
the self-discharging current of the accumulator at 100% of the set output voltage, i.e. the
resistance characteristic curve in this range (see Figure 6-10 6EP1424-3BA00 parallel
operation output characteristic curve (Page 46), Figure 6-11 6EP1436-3BA20 parallel
operation output characteristic curve (Page 47), Figure 6-12 6EP1437-3BA20 parallel
operation output characteristic curve (Page 47)).
Note
The value recommended by the battery manufacturer (dependent on the accumulator
temperature) must be set as end-of-charge voltage. A lead accumulator temperature of +20°
to 30° C is ideal; in this case, the recommended end-of-charge voltage is normally approx.
13.5 or 27 V.
Note
As protection against back e.m.f. and as polarity reversal protection, we recommend that a
suitable diode for at least 1.2 × rated current of the power supply with at least 40 V blocking
voltage is connected in series to the "+" output (connect the anode with "+" output of the
SITOP PSU300B and the cathode with the plus pole of the accumulator). The output voltage
of the power supply under no load must be set to the end-of-charge voltage plus the voltage
drop at the diode. For an end-of-charge voltage of, for example, 27.0 VDC (usual for 20° C to
30° C accumulator temperature, although the specifications of the accumulator manufacturer
must always be observed!) and 0.8 V voltage drop at the diode, the power supply without
load should be set to 27.8 V.
74
SITOP PSU300M/300B
Manual, 11.2014, C98130-A7574-A2-2-7629