Specialty Concepts SC3/15 - Manual (Page 10)

O P E R A T I O N
The charge regulation aspects of the SC3/15 are completely automatic. No user interface is
required after installation. This controller will regulate the charging of batteries during
conditions of heavy usage, or when left unattended for long periods of time.
SWITCHING SHUNT, PULSE CHARGE REGULATION: When in the charge mode, the
SC3/15 allows maximum available array current, to flow into the battery through a
blocking diode, lighting the "CHARGING" light. As the battery charges, the voltage will
rise slowly until it reaches about 14.5 volts. At this point, the "CHARGING" light goes
out and battery charging stops. When charging stops the battery voltage will fall, and
when the battery voltage drops to 13.0 volts, the SC3/15 will resume charging.
A TYPICAL DAY: A typical daily cycle will be as follows. As the charging starts for the day
and battery state of charge is low, charging will be continuous and the “CHARGING”
light will be on all the time. As the battery charges up, current will pass into the battery
for awhile and eventually stop. Later, charging will resume and the system will continue
this cycle throughout the day. During the course of the day, the duration of the charging
period of each cycle will get shorter (cycling on for shorter periods and staying off
longer). When the battery is close to full charge, it will pulse current into the battery to
achieve and maintain full charge. This pulse charging is indicated by the "CHARGING"
light occasionally turning on and off.
B A T T E R Y F U S E
BATTERY FUSE - A battery fuse is included for the SC3/15. This will protect the controller
from over-current from the solar panels, reverse polarity from the batteries and a short
circuit in the system. Fuse type: 15 AMP AGC.