Wanco Metro Variable Message Sign - Power System; Overview; Solar Panels; Batteries

40 Owner’s Manual
Wanco® Metro™ Message Sign
6.3 Power system
6.3.1 Overview
The message sign is powered by 12-volt batteries. Solar panels are used for charging
the batteries.
The charging system runs continuously, keeping the batteries charged. The system
automatically detects when the batteries are fully charged and will not overcharge
them.
Under optimal conditions, the batteries will remain charged and the message sign can
be used without having to charge the batteries using an external charger. If you use the
message sign continuously and the solar panels are not exposed to full sunlight all day,
the solar charging system may not keep the batteries charged sufficiently.
If there is not enough sunlight to keep the batteries fully charged, you will need to
charge the batteries using the external AC-powered charger, which is located inside the
battery box (see “Charging” on page 42).
The low-voltage-disconnect circuit detects when the battery charge falls below 11.2
volts DC, and shuts down power to the message sign. If a shutdown occurs, the
message sign will not function; the batteries must be fully charged.
6.3.2 Solar panels
For the solar charging system to function properly, the solar panels must be exposed to
full sunlight during daylight hours. If the location where the message sign will be used
is not a sunny location, the batteries must be charged using the external AC-powered
charger, which is located inside the battery box (see “Charging” on page 42).
The solar panels must be kept clean and completely unobstructed:
■ When necessary, clean the solar panels with a soft cloth or sponge and a cleaning
solution of mild detergent and warm water.
■ If a shadow or any obstruction blocks even a portion of any of the solar panels,
charging will be negatively affected and a significantly longer charge time will be
necessary.
6.3.3 Batteries
Although the message sign batteries are sealed and maintenance-free, regular care will
ensure proper function and extend battery life.
■ When working on or around the batteries, always observe battery safety precautions
(see “Safety” on page 41).
■ Routinely inspect batteries and cables, clean surfaces and terminals, and check battery
charge.
See the following pages for battery safety and care instructions.