Your vessel utilizes 12 volt D.C. electricity otherwise known as direct current. It is called D.C. because it flows only one way in a circuit. Specific wiring harnesses, gauges, batteries, battery cables, engine electrical components, dash switches,lighting, fresh water, shower sump and bilge pumps, refrigerators, toilets, along with any overcurrent protection are all part of the low voltage system. In this system, the black wire is designated as the “hot” or conductor wire and the white wire is referred to as the ground wire. All other current carrying wires are color coded to identify their circuit. This is especially helpful in troubleshooting and adding additional equipment. Be sure to review the wiring schematics in the technical drawing section.
Direct current is produced through the engine alternator while the boat engine is running. The alternator charges the batteries and sends current through the main distribution panel and battery switch via the required harnesses to the appropriate battery. Normal voltage on the dash volt meter is between 12 and 15 volts. Lower or higher readings could indicate a charging malfunction or weak battery.
The alternator is normally internally “excited” around 1200 revolutions per minute and will show normal readings up to 15 volts as the engine speeds above the idle range. At idle speeds below 1200, the volt meter will show around 12 volts. With the key in the “on” position and a fully charged battery the volt meter should read around 9 volts. Voltages below this indicate a possible electrical problem.
PREVENT SEVERE INJURY OR DEATH! USE ONLY APPROVED MARINE
REPLACEMENT PARTS THAT ARE IGNITION PROTECTED.
WARNING
!
PREVENT SEVERE INJURY OR DEATH! BE SURE TO DISCONNECT
ALL ELECTRICAL POWER SOURCES BEFORE ATTEMPTING TO REPAIR OR REPLACE ELECTRICAL COMPONENTS.
WARNING
!
Chapter 5
TYPICAL BATTERIES
Marine batteries are described and rated by the followingterminology:
A. Battery cold cranking performance rating- The discharged amperes( pressure in a circuit) that a battery at 0 degrees Fahrenheit can transfer in 30 seconds and still maintain 1.2 volts per cell or higher.
B. Cranking performance- The discharge in ampres that a new completely charged battery at 32 degrees Fahrenheit can continually deliver for 30 seconds, and maintain a voltage at the terminals of 1.2 volts or higher.
C. Battery reserve capacity- A number in minutes that a completelly charged battery at 80 degrees Fahrenheit can be continuously discharged at 25 ampres and hold a voltage of 1.75 volts or higher per cell (10.5 volts for 12 volt marine battery).
Since your vessel’s battery system is one of the most important on board systems, refer to the maintenance section for proper battery servicing and storage procedures. All battery terminals should contain a thin layer of anti- corrosion grease encapsulating the entire terminal surface. Battery electrolyte must be filled to the proper level to ensure a longer battery life. All fastening hardware must be kept tight to hold the batteries in place. Battery boots (red) must cover the entire positive terminal to prevent any possible arcing from tools, etc. Securely tighten all battery connectors to their respective posts.
Direct current is stored in the ship’s wet cell batteries. Twin engines use individual engine starting batteries. The battery circuit uses an on/off type battery switch that provides a positive battery disconnect, isolates all circuits and aids in protection against electrical fire,explosion and adds an extra security factor.
The dockside shorepower system through a battery charging system takes the place of the engines alternator to produce direct current.
The shore power cord sends 120/240 volts through the battery charger and it is converted to direct current at the battery charger. In this scenario the main D.C. distribution panel battery converter switch/breaker needs to be on for charging current to reach the batteries. When replacing batteries make sure the correct size and capacity are used. Always replace batteries in sets. Your Regal dealer will be able to assist you in obtaining the correct battery replacement. The factory normally recommends 650 cold cranking wet cell ampre batteries.
Typical Twin Battery Installation
IN THE DIRECT CURRENT (D.C) BATTERY SYSTEM
RED BATTERY CABLES ARE POSITIVE AND BLACK BATTERY CABLES ARE NEGATIVE.
IN THIS SYSTEM
CORRECT POLARITY MUST BE OBSERVED AT THE BATTERY TERMINALS WHERE THEY
ARE MARKED (+) FOR POSITIVE, (-) FOR NEGATIVE.
Systems
The battery charger is located in the engine room. Its function is to keep the batteries fully charged, to provide engine starting power and house D.C. circuit energy. The battery charger operates on 120 volt A.C. shore power to provide the A.C. source for the battery charger to function.
At the ship’s main A.C. panel the battery charger breaker needs to be energized for the batteries to be charged from dockside. The battery charger is a self-limiting device which means the charger output remains at a value that will not damage the charger if a short circuit develops at the D.C. output terminals over a specified period of time.