Blue Sky Energy - Solar Boost 2000E
7
SETUP AND WIRING DIAGRAM
FIGURE 3
SETTING CHARGE VOLTAGE
Charge voltage should be set to the battery manufacturers recommendations. The factory setting of 14.0 volts is suitable for most lead-acid chemistry
batteries and does not typically require adjustment. For a predominately float application a somewhat lower voltage of 13.8 volts may be beneficial in decreasing
water loss. For a heavily cycling application, a somewhat higher voltage of 14.5V may be beneficial in decreasing charge time and increasing amp-hours delivered.
The adjustment potentiometer location is shown in Figure 3. With the Charge Status LED blinking indicating that the battery at or near full charge, adjust the charge
voltage potentiometer to the desired battery charge voltage as displayed on the 2000E digital display. If optional temperature compensation option is installed,
disable temperature compensation, adjust the charge voltage to the desired 80
°
F value, and then turn temperature compensation back on.
Since charge voltage is calibrated by adjusting actual battery charge voltage as displayed on the 2000E, setting charge voltage therefore requires that the
battery be at or near full charge so that the unit is actually controlling battery voltage at the charge voltage setpoint. This can sometimes be hard to achieve when
battery capacity is large compared to available PV charge current. Charge Voltage Calibration Tool P/N 930-0031-01 as described in technical bulletin #100209
simplifies charge voltage calibration be eliminating the need to have the battery be highly charged. To access this and other technical bulletins, see
www.blueskyenergyinc.com
.
MAXIMUM POWER VOLTAGE
The nominal setting for this adjustment is the difference between the PV panel’s open circuit voltage (V
OC
) and maximum power voltage (V
MP
). These
voltage values are typically listed on both the PV panel datasheet and on the rating label affixed to each PV panel. This value needs to be set correctly for the
MPPT system to deliver maximum current boost. The factory setting is 4.4 volts which is the appropriate value for many popular 36 cell PV modules. These
modules typically list V
OC
at
≈
21.4 volts and V
MP
at
≈
17.0 volts, which yields; 21.4 volts - 17.0 volts = 4.4 volts.
OPTIMIZING
MPPT
The combined effects of manufacturing tolerances in the PV panel and wiring resistance in a particular installation can sometimes shift the optimum
setting. While not required, it is recommended that for maximum MPPT current boost performance this adjustment be fine-tuned following installation. This is
a one-time setup and does not require seasonal adjustment. Fine tuning is also desirable following installation of additional PV panels or other substantial
system change.
Fine tuning is easily accomplished by slowly adjusting the MPPT adjust potentiometer to obtain maximum Output Charge Current. Adjustment is best
done in near full sun with a discharged battery and cool ambient temperatures. The red MPPT Active LED above the potentiometer turns on when MPPT is
The 2000E cannot limit and
control battery voltage if
temperature compensation
is enabled with sensor
installed reverse polarity.
Output charge current will
be disabled if temperature
compensation is enabled
without sensor installed.
