MPPT OVERVIEW
6
2.6
Load Connection
The Load Connection can only support a Load equal to the MPPT size. Therefore a 10A LED MPPT
can only support a maximum 10 Amp Load.
2.7
Connecting The Unit
Ensure that all cabling used is kept as short as possible as volt drops caused by long cables will
reduce the efficiency of the Tracker. Minimum recommended wire diameter = 4 mm²
First connect the
Load
and then the
Battery
.
The LED display will show the Tracker checking the battery. The Medium LED will flash once for a
12V battery and twice for a 24V system. At the same time the buzzer will sound once for a 12V and
twice for a 24V system.
Connect the solar panel. The panel LED will come on if there is sufficient panel power.
The Regulator will now read the solar panel voltage and select the optimum power point. If there is
sufficient power in the solar panel the Tracker will now start charging.
2.8
Charging The Batteries
Boost Mode
: The batteries are charged until they reach the boost voltage 14.8V for a 12V battery set
or 29.6V for a 24V battery set. When the batteries reach this level the MPPT will hold this rate for a
minimum of 1/2 hour indicated by the flashing BOOST LED and then switches to Float Mode.
If the batteries fall below the BOOST voltage then the timer is reset i.e. at night or during cloudy days.
This ensures that the batteries are fully Boosted.
FLOAT MODE: Boost light flashes -
The batteries are now essentially in trickle charge mode.
2.9
Maximum Panel Voltage (Voc) and (V
MP
) Per Battery Bank
Suggested Maximum Panel Voltage for a 12V Battery Set
V
MP
(Max Power Point Voltage)
“Min Charge Voltage”
15V
V
OC
(Max Open Circuit Voltage)
“Max Charge Voltage”
24V
Suggested Maximum Panel Voltage for a 24V Battery Set
VMP (Max Power Point Voltage) “Min Charge Voltage”
30V
V
OC
(Max Open Circuit Voltage)
“Max Charge Voltage”
45V
50Voc is the absolute maximum. Systems should be designed for a max of 45Voc due to the
increase in panel voltage due to colder Panel Temperatures.
Refer to your solar module
documentation for the worst-case (coldest) module temperature voltage, should provide Voc vs.
temperature data
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