SPK
Solar Panel
LOCATION
The solar panel should oriented as much as possible toward
the midday sun. Locate where there is no significant shading
of the solar panel. The Solar Charge Controller and Sealed
Lead Acid (SLA) battery should be located in close physical
and thermal proximity. Both must be shaded from direct
sunlight to minimize temperature differences between them
which will greatly diminish the battery service life. Also insulate
the bottom of the battery if heat could be absorbed from the
surface (concrete, metal etc.) on which the battery is resting.
Also take measures to prevent accumulation of moisture (rain,
snow, ice, flooding) between the battery terminals which could
discharge the battery.
If the battery and Solar Charge Controller are housed in an
enclosure, the outside must be white or shiny metallic to mini-
mize solar heat build up inside that is seriously detrimental
to the service life of the battery. Even light colors (such as the
standard ANSI 61 Gray) can elevate the interior of the enclosure
by 40F (22C.) If other colors are used, the enclosure must be
shaded from direct sunlight or painted glossy white. In addition,
because even sealed batteries could vent if the Solar Charge
Controller fails, for safety reasons the enclosure should be
vented, particularly if it contains other electrical equipment.
290 mA (typical at design operating point)
17 V (typical at design operating point)
14.2”
8.5”
4 pounds (solar panel and mounting bracket)
Bracket, band clamps and mounting hardware for 1-1/2 or 2 inch vertical pipe
-40˚ F to +158˚ F (-40˚ C to +70˚ C)
High efficiency series PWM regulator with temperature compensation and built-in lightning protection
Electrical Current
Voltage
Dimensions Height
Width
Weight
Mounting
Operating Temperature Range
Change Controller
SPECIFICATIONS*
*Specifications subject to change
For powering Dwyer Instruments Inc. mechanical meters
along with display electronics, use a 12V Sealed Lead Acid
(SLA) deep-cycle battery with a minimum capacity of 22 Amp-
hours. This should provide a conservative 40 day backup with
maximum battery service life. Marine/RV grade deep-cycle
batteries or automotive batteries may be used but must be
upsized in Amp-hour capacity by two times and four times
respectively to achieve the same battery service life in most
applications.
For powering Dwyer Instruments Inc. low power (<50mA)
magnetic flow meters use only deep-cycle SLA batteries (not
marine/RV orautomotive grade batteries) with a minimum ca-
pacity of 33 Amp-hours. In climates where meters are operat-
ing in full pipe mode much of the time with extended periods
of cloudy days, operating continuously through the year, or in
latitudes above 50 degrees, the required battery Amp-hour
capacity should be reviewed before selection. To learn more,
consult the Appendix in our solar power application note
found at www.dwyer-inst.com.
In summary, the minimum recommended battery capacity, as
described above, will be adequate in most climates and ap-
plications. However, under marginal conditions, a larger ca-
pacity battery may provide superior reliability, better battery
service life and lower life-cycle costs.
BATTERY SELECTION
TM
