● Minimum number of cells in series: 72 (2x 12V panel in series
or one 24V panel).
● Recommended number of cells f or highest controller
ef f iciency: 144 cells (4x 12V panel or 2x 24V panel in series).
● Maximum: 216 cells (6x 12V or 3x 24V panel in series).
48V battery and mono- or poly cristalline panels
● Minimum number of cells in series: 144 (4x 12V panel or 2x
24V panel in series).
● Maximum: 216 cells.
Remark: at low temperature the open circuit voltage of a 216
cell solar array may exceed 150 V, depending on local
conditions and cell specifications. In that case the number of
cells in series must be reduced.
3.3 Cable connection sequence (see figure 1)
First: connect the battery .
Second: connect the solar array (when connected with rev erse
polarity , the controller will heat up but will not charge the
battery ).
3.4 More about automatic battery voltage recognition
The sy stem v oltage is stored in non v olatile memory .
In case of a 24 V or 48 Vbattery , a reset (to 12 V) occurs only
when the output v oltage decreases to less than 2 V and the
v oltage on the PV input exceeds 7 V. This may occur when the
battery has been disconnected bef ore PV v oltage starts to rise
in the early morning. When the (24 V or 48 V) battery is
reconnected later during the day , the sy stem v oltage is restored
to 24 V resp. 48 V af ter 10 seconds if the battery v oltage
exceeds 17,5 V resp. 35 V.
Automatic v oltage recognition can be switched of f and a f ixed
12/24/36 or 48 V sy stem voltage can be set with a computer or
a Color Control panel.
The controller can be reset by short circuiting the output and
apply ing a v oltage exceeding 7 V on the input (f or example with a
small power supply , or a solar panel) during a f ew seconds. Af ter
a reset, the controller will automatically adjust itself to a 12V
sy stem, a 24V sy stem (when connecting a 24 V battery with at
least 17,5 V) or a 48V sy stem (when connecting a 48 V battery
with at least 35 V). A computer or a Color Control panel is
required to set the MPPT to 36V.
5