For DXM devices without an LCD, adjust the I/O board Modbus register 6071. Set the register to 0 to select battery
charging from a solar panel, and set to 1 to select battery charging from incoming 12 to 30 V dc supply.
Here are a few DXM configuration tips to help minimize the power consumption (may not apply to all models).
•
If Ethernet is not being used, save up to 25% of the consumed power by disabling Ethernet. Set DIP switch 1 to
the ON position on the processor board then reboot.
•
Instead of powering external devices all the time, take advantage of the switched power mechanisms to turn off
devices when possible.
•
Minimize the number of cellular transactions and the amount of data pushed across the cellular modem.
5.3.2 Solar Components
The components of a solar system include the battery and the solar panel.
Battery
The DXM solar controller is designed to use a 12 V lead acid battery. The characteristics of a solar system require the
battery to be of a certain type. There are basically two types of lead acid batteries:
•
SLI batteries (Starting Lights Ignition) designed for quick bursts of energy, like starting engines
•
Deep Cycle batteries - greater long-term energy delivery. This is the best choice for a solar battery.
Since a solar system charges and discharges daily, a deep cycle battery is the best choice. There are different versions of a
lead acid battery: wet cell (flooded), gel cell, and an AGM (absorbed glass mat).
Wet cell batteries are the original type of rechargeable battery and come in two styles, serviceable and maintenance free.
Wet cell batteries typically require special attention to ventilation as well as periodic maintenance but are the lowest cost.
The gel cell and AGM battery are sealed batteries that cost more but store very well and do not tend to sulfate or degrade
as easily as a wet cell. Gel or AGM batteries are the safest lead acid batteries you can use.
Battery Capacity
Battery capacity is a function of the ambient temperature and the rate
of discharge. Depending upon the specific battery, a battery operating
at –30 °C can have as much as 40 percent less capacity than a battery
operating at 20 °C. Choose enough battery capacity based on your
geographical location.
A larger capacity battery typically lasts longer for a given solar
application because lead-acid batteries do not like deep cycling
(discharging a large percentage of its capacity). Depending upon the
battery, a battery discharging only 30 percent of its capacity before
recharging will have approximately 1100 charge/discharge cycles. The
same battery discharging 50 percent of its capacity will have
approximately 500 charge/discharge cycles. Discharging 100 percent
leaves the battery with only 200 charge/discharge cycles.
Batteries degrade over time based on discharge/charge cycles and
environmental conditions. Always monitor the battery system to obtain
the best performance of the solar powered system.
Use this as a guide to the approximate state of
charge and in determining when to apply
conservation measures.
Average Voltage Readings Relative to Battery
Change
State of Charge (%)
Open Circuit Voltage
100
13.0 or higher
75
12.6
50
12.1
25
11.66
0
11.4 or less
Solar Panel
Banner solar panels come in two common sizes for the DXM Controller: 5 Watt and 20 Watt. Both panels are designed to
work with the DXM Controller but provide different charging characteristics. Use the 5 watt panel for light duty operation
and use the 20 watt panel when you require greater charging capabilities.
Solar Panel
Voltage
Current
Typical DXM Configurations
5 Watt
17 V
0.29 A
DXM slave controller, ISM radio, I/O base board
20 Watt
21 V
1 A
DXM Controller with ISM radio and Cellular modem
Photovoltaic panels are very sensitive to shading. Unlike solar thermal panels, PV solar panels cannot tolerate shading
from a branch of a leafless tree or small amounts of snow in the corners of the panel. Because all cells are connected in a
series string, the weakest cell will bring down the other cells' power level.
Good quality solar panels will not degrade much from year to year, typically less than 1 percent .
Solar Panel Mounting
DXM100-Bx Wireless Controller Instruction Manual
www.bannerengineering.com - Tel: 763.544.3164
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