ST – II Series POWER SUPPLIES
USER INSTRUCTIONS
AC/DC Power Supply:
This provides an isolated 13.65Vdc output for powering of the load and
float charging of the battery. Battery current is sensed and monitored by the power supply to ensure
that the maximum charging current is not exceeded.
Battery Features:
The power supply provides full battery management as per the following.
The power supply is a four stage battery charger with Boost (VBoost = 14.05V), Float (VFloat =
13.65V), Store (VStore = 13.25V) and Trickle charge modes to ensure long battery life.
Charging
current is limited to a maximum of 10A (ST20-II) and 15A (ST35-II). This provides
optimum life for the batteries.
To charge at the maximum battery charge current above, ensure the load current plus battery current
is equal or less than the maximum output current. The charging current will be reduced in situations
where the difference between the rated output current and the load current (the available charging
current), is less than the maximum charging current.
Also note that the battery current sense is provided in the “Batt +ve” battery output. For this feature
to work, the load “+ve” and battery “Batt +
ve
” should not be cross connected. (Appliances should
not be connected to both the “Batt +ve” and “+ve” terminals of the power supply. Appliances
should be connected to the “+ve” and “-ve” load terminals).
Low Voltage Disconnection
of the batteries is provided to prevent deep discharge of the battery.
Automatic reconnection occurs when battery voltage recovers.
Battery Current Drain
is less than 2mA.
Trickle Charge
to the battery is always present. When the battery voltage is below the LVD (Low
voltage disconnect) re-connect voltage (<10V and the mains power or auxiliary power is available,
the battery will be charging at 0.8A. When the battery voltage is sufficient (>10.5V for first power
up, 11.5V and 11.7V for subsequent reconnection with and without mains respectively) the LVD
will connect the battery and allow float charging at 10A/15A (ST20-II/ST35-II). The Trickle
Charge feature is provided to allow “very” flat batteries to be charged at a rate, which will extend
their life.
Auxiliary Power Input:
The power supply terminal “Aux In +VE” provides an alternative option
for powering of the load and float charging of the batteries when mains voltages are not present.
This input is to be powered by a suitable +12V system. (i.e. CAR). The voltage of the auxiliary
power source should not exceed 14.8 volts.
When operating via the external input, current and voltage control for the battery must be provided
from the external source. The ST20-II/35-II does not provide battery current limit or voltage control
when operating in this configuration. Trickle Charge is still functional when powered through
“Aux In +VE” terminal of power supply.
Suitable fuse protection must be provided for this input. A fuse rating not exceeding 20 Amps for
ST20-II and 30 Amps for ST35-II must be used.
Solar power should be connected directly across the battery terminals with a voltage regulator in
series. A solar panel voltage regulator with maximum output voltage not exceeding 14.8 volts must
be used at all times. Failure to use a voltage regulator may result in power supply damage.
Generator 12 volt outputs should not be connected across battery terminal whilst battery is
connected to power supply or connected to the “Aux In +VE” terminal of power supply. Serious
power supply damage or internal explosion may occur. If a flat 12 volt battery has to be charged
using the generators 12 volt output, it should first be disconnected from the power supply. Once
battery has being charged it can then be reconnected to power supply.
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