Appendix; Fundamentals In Detail - intervolt DCC Pro Installation & Operation Manual

Fundamentals in Detail

CHARGING FUNCTIONS
Soft start: This function is the initial phase of the boost stage cycle. In soft start
the current is allowed to build gradually over time, e ectively controlling the
high inrush current normally experienced at 'switch on' . Controlling the inrush
current reduces the risk of further damage if the battery is unserviceable and
prevents potential issues with any equipment that may be powered from the
battery at the time. Many manufacturers refer to a soft starting feature as an
additional stage. In reality however it is simply another process used for
controlling the boost cycle to properly manage the auxiliary battery. The soft
start function is timed and under full load will allow the current to build to
maximum, four minutes after initialising.
Thermal control: This function is enabled when the temperature of the Charging
Device rises above a pre-determined limit. When the environmental temperature
exceeds 50°C and the Charging Device is under full load (25 Amps), thermal
control is initiated. When thermal control is activated it enters a pre-programmed
control mode which allows current output to continue subject to temperature
rise. As the temperature increases the current is reduced proportionally rather
than immediately so that the charging process can still be maximised for the
hottest of conditions. This process is directly inverse to the soft start function.
Input Voltage control: This function is incorporated to compensate for voltage
drop caused by undersize cable, poor connections, improper termination, etc. by
comparing the input voltage at the main battery terminal with the voltage at the
Charging Device itself. It does this by momentarily disconnecting the auxiliary
battery (every two minutes for 250ms), thereby removing the load. At this time it
evaluates the voltage with and without load to determine the true voltage. It will
then establish if the true Voltage is high enough to continue charging or to
implement low voltage shut down. If the true Voltage is high enough, the
charging current will be automatically adjusted according to the evaluation, this
will prevent the Charging Device from cycling on and o .
CONTROL MODES
Voltage control mode: In Voltage control mode the charging control process is
automatic and is based on voltage sensed at the input and output terminals of
the Charging Device. When the main battery Voltage rises above 12.8V the
Charging Device will commence operation. The charging cycle is determined by
the auxiliary battery voltage and may enter BOOST or FLOAT stage depending on
this gure (see Charging Methods on pages 37-40). If solar power is actively
available, SOLAR stage may be initiated.
36