24 | SAMLEX AMERICA INC.
Now, the capacity of the batteries is determined based on the run time and the
usable capacity.
From Table 1.9 “Battery Capacity versus Rate of Discharge”, the usable capacity at 3 Hour
discharge rate is 60%. Hence, the actual capacity of the 12V batteries to deliver 300 Ah will be
equal to: 300 Ah ÷ 0.6 = 500 Ah, and the actual capacity of the 24V battery to deliver 150 Ah
will be equal to 150 Ah ÷ 0.6 = 250 Ah.
And finally, the actual desired rated capacity of the batteries is determined
based
on the fact that normally only 80% of the capacity will be available with respect to the rated
capacity due to non availability of ideal and optimum operating and charging conditions. So the
final requirements will be equal to:
FOR 12V BATTERY: 500 Ah ÷ 0.8 = 625 Ah (note that the actual energy required by the load
was 300 Ah).
FOR 24V BATTERY: 250 Ah ÷ 0.8 = 312.5 Ah (Note that the actual energy required was 150
Ah).
It will be seen from the above that the final rated capacity of the batteries is almost 2 times
the energy required by the load in Ah.
Thus, as a Rule of Thumb, the Ah capacity of the
batteries should be twice the energy required by the load in Ah.
1.14.15 Charging Batteries
Batteries can be charged by using good quality AC powered battery charger or from alternative
energy sources like solar panels, wind or hydro systems. Make sure an appropriate Battery
Charge Controller is used. It is recommended that batteries may be charged at 10% to 20%
of their Ah capacity (Ah capacity based on 20 Hr Discharge Rate). Also, for complete charging
(return of 100% capacity), it is recommended that 4-Stage Charger may be used as follows:
Float Application Charging (2-Stage)
Stage 1 (Bulk Stage at constant current)
"
Stage 2 (Absorption Stage at constant voltage.
May also be called Float Stage in some applications).
Normal Charging (3-Stages)
Stage 1 (Bulk Stage at constant current)
"
Stage 2 (Absorption Stage at constant
voltage)
"
Stage 3 (Float Stage at constant voltage)
Equalization Charging (4-Stages)
Stage 1 (Bulk Stage at constant current)
"
Stage 2 (Absorption Stage at constant
voltage)
"
Stage 3 (Equalization Stage at constant voltage)
"
Stage 4 (Float Stage at
constant voltage)
Please refer to Section 5 for details of charging algorithm used in the Battery Charger Section of
EVO
TM
Series Inverter/Charger.
SECTION 1 |
Safety Instructions & General Information
Summary of Contents for Evolution EVO-1212F
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