ACSecondarySystems

ACAlternating current Secondary System

Alternator

Each engine (if there is more than one) will have a high-capacity dual-output alternator and multistage regulator, with separate charging circuits for the starter and house batteries. AAmpere (amp), SI unit of electrical current backup manual switch and regulator are provided. The regulator must be suited to the type of battery: Flooded cells require an equalization charge after the main charge; whereas gel and AGMAbsorption glass mat cells usually do not. Typical vendors are: Ample Power, Balmar, Hehr Power Systems, JackRabbit Marine and Sea Air Land Technologies, Inc.

If the boat will be unattended for periods at least one engine must autostart on a schedule to keep the batteries charged.

Trickle Charge System

In case the main charging system fails while the boat is unattended, a DCDirect current trickle-charge system can be provided. Trickle charging is also a good idea because there are usually parasitic loads on a battery system that will slowly discharge it. Deep discharge batteries do not want to be trickle charged at a high rate: 3%percent is recommended. Thus a boat with a house bank of 1000 AHAmpere-hours (A*H) requires a trickle charge of 30 AH.

Wind turbines and solar panels are ideal for a trickle-charge system; although they are not suited as a main power source. Unfortunately, as a main power source, each of them has a significant performance drawback in the context of a small- to medium-size boat. They simply need too much real estate.