Samplex Europe SEC-1245E, Owner'S Manual

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BATTERY VOLTAGES – CHARGED AND DISCHARGED CONDITIONS
The cell voltage of a battery depends upon the temperature of the battery and has a negative
temperature coefficient – the voltage level increases at lower temperature and decreases at
higher temperature The voltages are normally specified at 26.7º C.
On a 12 volt battery, the no load battery voltage is between 11.4 VDC (fully discharged)
and 12.9-13.0 VDC (fully charged). On a 24 volt battery, the no load battery voltage is
between 22.8 VDC (fully discharged) and 25.8 -26.0 VDC (fully charged).
CHARGING STAGES - I, Uo, U
The charger is preset to charge in 3 stages as described in the succeeding paragraphs. The
charger is called “IUoU Charger” based on the DIN designation of the charging stages – “I”
Phase, “Uo” Phase and “U” Phase. Please refer to the charging curve given at Figure 4 for
understanding the 3 charging stages.
NOTE: The charging voltages indicated below pertain to battery temperature of 26.7º C
Stage 1 - Constant Current, Bulk Charge Mode (I Phase): When the charger is first
condition of the battery. When the battery is deeply discharged, it will initially try
to draw a very large current. If this initial current draw is 45 A (SEC-1245E) or more than
60 A (SEC-1260E) or more than 80 A (SEC-1280E) or more than 40A (SEC-2440E)
or more than 25A (SEC-2425E), the charger will enter Stage 1 – The Bulk Charge Mode
(“I” Phase). During this period, SEC-1245E will deliver a constant current “I”= 45 A
SEC-1260E will deliver a constant current “I”= 60 A, SEC-1280E will deliver a constant
current “I” = 80 A SEC-2425E will deliver a constant current “I”= 25 A and SEC-2440E
will deliver a constant current “I” = 40 A. The charger will be operating under current
limit condition andthe voltage at the charging terminal will be same as the actual voltage
of the discharged battery. The voltage of the battery will slowly start rising and when the
battery voltage approaches voltage U = 13.8 V (SEC-1245E, SEC-1260E and
SEC-1280E) or voltage U = 27.6 V (SEC2425E, SEC-2440E), the current drawn
by the battery will reduce below the current limit value of 45 A (SEC 1245E),
60 A (SEC-1260E), 80 A (SEC-1280E) and 25 A (SEC-2425E), 40 A (SEC-2440E).
The charger will exit current limit condition and will now output constant voltage of
U = 13.8 V (SEC-1245E SEC-1260E and SEC-1280E) or constant voltage U = 27.6 V
(SEC-2425E SEC-2440E).
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