Article by Pat Schrawder
KEEP YOUR 12 VOLT SYSTEM WORKING PROPERLY
One of the most prevalent sources of problems with electronics is improper supply of voltage. If your boat’s batteries are not supplying the correct voltage, equipment will not work correctly and, if over-supplied with voltage as sometimes occurs when you crank your engines and your alternator charges maximum, it can actually damage your equipment. Fortunately, there are a number of items on the market designed to help with these problems. Let’s look at just a few:
The abrupt DC system voltage drop that accompanies engine starting can cause microprocessor-driven communication and navigation electronics to “dump” programmed memory. The Voltage Starting Protector Device is an item that attempts to solve this problem by providing supplemental voltage to your electronics while the engine is cranked. It contains a rechargeable battery, which is switched on-line to your electronics when the starter switch or solenoid is engaged. When the engine is running, the device goes off-line and your alternator recharges the internal battery. It works very similarly to a battery back-up device that is commonly used to protect office computers and cash registers during power outages.
Marine communication and navigation electronics such as programmable data transceivers, GPS and other microprocessor-controlled devices also require clean and steady DC input power. Their sensitive circuitry is highly vulnerable, not only to voltage drop from engine start, but also noise and line spikes from alternators and motors, as well as conducted noise from various other electronic devices. There is a Power Conditioner that helps to correct this problem. It absorbs line "spikes", filters out electrical interference, and provides supplemental voltage/battery back up for several minutes.
Insufficient charging of one or more batteries can also be a problem. Battery isolators allow charging of multiple batteries automatically from one or two alternators, and prevent discharge or "dumping" of one battery into another. Each battery is charged according to its need without overcharging.
Discharging batteries beyond a critical low voltage can damage the batteries and/or load, and require a longer recharge interval. A low voltage disconnect prevents this condition. It is installed in-line between the battery and the load. The unit continually monitors battery voltage and if it falls below a preset voltage threshold, the load is automatically disconnected. When batteries are recharged past another pre-set voltage the load is reconnected. Connect and disconnect points are user adjustable.
So what if your batteries are going bad and you don’t know it. Well, there is something for that as well. At least one manufacturer makes a series of digital read out meters that monitor your system. According to the manufacturer, these instruments provide comprehensive monitoring of on-board AC and DC electrical systems. They give quick, accurate, up-to-the moment information on all important aspects of electrical system status – voltage, current, power consumed, power available, AC frequency, abnormal system conditions, and more. They even make use of a Remote Alarm relay Option that activates from the instrument alarm signal output terminal allowing remote activation and/or connection to the vessel’s 12 or 24 volt alarm panel.
This is just a sampling of what’s out there to make your boating easier and safer. Some items are inexpensive and others are more costly.
A basic item that is inexpensive for your boat but almost a necessity is a voltage meter to help you identify problems. It is also a good idea to stock your boat with some basic supplies such as fuses, assorted screwdrivers, terminals connectors and a tool to crimp them, electrical tape, a flashlight and anti-corrosion compound. I like CRC 2-26 but there are others. Call it your First Aid Kit for electronics.
Pat and her husband, Larry are owners of L&L Marine Electronics in West Ocean City, MD.
