Airmar Acoustic Deterrent System—dB Plus II™ - Manual (Page 6)

4
Power Supply System
The dB Plus II

system requires 24VDC, supplied by lead acid batteries, to provide adequate power
surge levels during sound transmission and a temporary reserve of power for times when the batteries
cannot be recharged. Power inverters are unable to meet this requirement and are not recommended.
• Shore Power —At locations where shore power is available, AC mains, two 12V batteries and a
battery charger(s) is advised.
• Batteries —At sites where shore power is not available, a system of four 6V deep cycle batteries is
recommended (see Figure 3). Four 6V batteries connected in series provides much more reserve
capacity than two 12V batteries. Deep cycle batteries are necessary because they can withstand
the many charge and discharge cycles which occur when operating the
dB Plus II

system.
Consult your power supply manual for proper installation and maintenance of the power supply
equipment.
The condition of the batteries must be checked daily, regardless of the type of charging system used. The
voltage level must never drop below 24V, and electrolyte levels must be maintained in accordance with the
manufacturer’s instructions. Terminal connections must be kept tight and free of corrosion.
Battery Charging
• Solar panels —Depending on the climate, a four module regulated solar panel array may be
adequate.
• Wind generators —In windy locations, regulated 24V wind generators offer an alternative means
of charging the batteries.
• Solar and wind —Weather conditions effect the performance of both solar panels and wind
generators. A charging system that combines both may provide a reliable charging source since
one of these conditions is present on most days.
• Portable generator —Use of an engine powered generator with a battery charger is much less
desirable. Manual charging must be done often enough to keep the batteries above 24V. However,
a portable generator could be used as a backup to solar or wind systems.
Any charging method may have difficulty meeting the power demand. Two sets of batteries that can be
rotated is recommended. While one set is in use, the alternate batteries can be fully charged.
Battery Enclosure
The batteries should be protected in a weatherproof structure. A wooden enclosure with venting and
drainage holes is very effective, causing less condensation than one made of plastic or fiberglass. In
locations where the temperature drops below freezing, rigid foam insulation on the inside is highly
recommended.
6V
+
+
+
+
6V
6V
6V
external
“Insufficient Power”
alarm
# 22-243
alarm cable
# 22-242
power cable
Note: 12V batteries are
hooked up in series
(ref. negative-to-positive)
in same manner as shown.
Figure 3. Power supply cable hookup
red
yellow
black