AC DC Electric panels.

We offer the complete range of Blue Sea AC and DC panels.

AC Main Panels are AC panels that include a double-pole main on/off switch and are designed for use as the primary AC panel on board

AC Multi-Source Panels are AC panels that include a source selector switch for two or more sources and are designed as the primary panel on board a boat with more than one source of AC (e.g. shore power and a generator, or two 30A shore power inlets)

AC Branch Panels do not include a main switch and are for use as sub-panels fed from a main panel, or as a main panel when a separate main on/off switch is installed

AC Source Selection Panels include a source selector switch or main switch but no breakers, and are for use with a separate main or branch panel, or to select between shore power and inverter power

AC/DC Panels combine AC breakers and DC breakers in one panel

DC Panels include both DC Main Panels (with a 100A main breaker) and DC Branch Panels

There is a choice in many panels between toggle switches and rocker switches. Panels with toggle switches come in two versions with white or black toggles.

All panels come installed with a number of breakers and may have some spare positions. Extra breakers are available in a range of ratings from 5A to 50A, and in white, black or red.

Standard features on Blue Sea panels include:

* Back lit circuit label positions on all panels

* ON indicating LEDs in all breaker positions

* Countersunk mounting holes

* Two-part polyurethane slate gray finish

* Heavy 1/8" aluminum alloy

* Tin plated copper busses

* Industry standard height and width

* Large number of circuit labels available

Galvanic Isolation.

Boats linked to shore power at a dock are potentially exposed to a form of galvanic corrosion caused by faults in wiring on other boats or in the marina's AC ground connection. Stray DC currents can flow through the common AC ground which is connected to all the boats. These currents can then flow through metal fittings on a boat, through the seawater and up into another boat through its underwater metal fittings. The result is a circuit between the two boats which will eat up the zincs at a rapid rate - and will then start on the props themselves.

A galvanic isolator installed in the ground wire of the AC circuit will block these stray currents while preserving the AC ground's safety function. we recommend the use of a galvanic isolator for all boats kept at docks and plugged into shore power.

Battery Chargers.
Battery chargers are powered by the shore power connection on your boat, or by an on-board AC generator. They convert the 120V AC input to DC for use in charging one or more battery banks. All the chargers we install are three-stage chargers which take the batteries through an optimal bulk/absorption/float charging cycle. If you have AGM or Gel batteries, you should use a charger with temperature compensation through an external battery temperature sensor to optimize the charge to the batteries.
Three-stage chargers take the batteries through the bulk, absorption and float stages. In the bulk stage, the charger puts a fast charge into the batteries and the battery voltage slowly rises from its initial level to a target voltage that depends on the battery type and temperature. When this voltage is reached, the charger switches to absorption mode in which it holds the voltage constant as the battery continues to absorb charge. When the current absorbed by the batteries decreases below a fixed cutoff level, then the charger switches to the float stage, where it holds the battery voltage at a lower, safe 'maintenance' level.
The charge flowing into the batteries is highest at the start of the bulk stage, and then slowly decreases as the voltage rises. By the end of the bulk stage, the battery is 80-85% charged.
The absorption and float voltages are different for different battery chemistry (i.e. flooded, AGM or Gel). As the optimal charging voltage for AGM and Gel batteries vary with temperature, you should always use a charger with both a selectable program for the battery type and a temperature sensor for these sealed batteries.

If your boat is kept at a dock and left plugged in to shore power, a smaller charger can be used and left to run overnight. If you are charging from a generator, you may want a larger charger to reduce the generator running time.


Inverters convert DC power from the batteries into AC power that can be used to power 120V or 240V appliances. A pure sine wave inverter will produce AC output that is indistinguishable from domestic grid power. These inverters can be used to power any kind of equipment. A modified sine wave inverter will produce AC output with a more jagged, square sine wave shape. This is OK for use with appliances such as microwaves, hair driers and blenders but should not be used for sensitive equipment such as stereos, LCD TVs, DVD players or satellite communications. The inverter should be sized so that its rated power output can handle all the simultaneous loads that will be put on it. Some devices cause a temporary power surge on start up, and the unit must be rated to handle that surge without overloading.

Combined inverter/chargers contain both an inverter and a charger. When shore power is connected, the unit functions as a battery charger. When the external source of AC power is removed, the inverter switches on and continues to supply AC power to the AC breaker panel.

Combiners & Switches.

The batteries and battery switches installed as standard on many production boats are usually inadequate for the demands that owners make on them. Battery banks are always too small, and flooded wet-cell conventional batteries need regular maintenance and have a relatively short lifespan. Conventional (1-2-Both) battery switches can damage alternators if misused, and can easily be left in the wrong position.

The first steps in upgrading the electrical system on your boat are to increase the size of the house bank and replace the wet-cell batteries with sealed, maintenance-free AGM batteries, and then to replace the battery switch with another switch or panel that properly separates the house and start circuits

We recommend your local supplier of Lifeline AGM batteries, or West Marine Dual-Purpose AGM batteries, which are a private-label version of the East-Penn PowerTech batteries. Many of our customers are also prefer the Trojan 6V batteries.

When charging more than one battery bank from an alternator or other charging source, a way must be found to distribute the charge between the battery banks. Many boat builders install passive isolators(diode controlled), so that the alternator output feeds the isolator and this in turn feeds charge to the batteries while keeping the battery banks electrically isolated from each other. This is simple, and cheap, but ineffective. The isolator introduces a voltage drop of up to 0.7V, meaning that the batteries are never fully charged. Over time, the batteries will become sulfated and fail prematurely. A better solution is to use an active device(ACR) that connects between two battery banks and that monitors the voltage on the source battery bank and then connects the batteries together when this voltage rises above a preset level - usually about 13.0 - 13.2V. These active combiners do not cause any voltage drop and will ensure that all batteries are fully charged.

Alternators & Regulators.

An alternator is a device that converts mechanical (rotational) energy to electrical energy. On boats, alternators use engine power to generate electricity which can then run on board equipment or charge batteries.

Most alternators supplied as standard equipment on boats are inadequate for the demands made on them. They are often automobile-type models, with low output at low engine speeds and a built-in regulator that has a simple one or two-stage charging cycle. The consequences of using these alternators include extended battery charging time; a steady decline in battery efficiency due to inadequate charging; insufficient power to run DC electrical devices on board and insufficient power to run an inverter to produce AC power on board.

Marine high-output alternators are more robustly constructed, with closer tolerances, heavier wire, heavier components and better fan cooling. They produce more power than standard alternators, and most importantly they produce more power at low engine speeds. Used with a multistage external regulator, they ensure correct battery charging, extending the life of your batteries.

Using a high-output marine alternator to charge batteries quickly when the engine is running at cruising speed is much better for your engine than having to run the engine at idle for prolonged periods to charge batteries. A marine alternator can extend the life of your main engine.

When using an alternator to charge batteries, the voltage must be carefully controlled so as not to damage the batteries. A voltage regulator or charge controller is used for this purpose. Some alternators have regulators built into the case or attached on the back of the case, while others have a separate external regulator. Simple internal or attached regulators are common on alternators built for cars. External, multistage regulators are recommended for marine use, especially when Gel or AGM batteries are being used, as they give better control over the battery charging cycle.

Battery Monitoring.

Every boat should have a battery monitor. The first step in balancing or upgrading your electrical system is to understand what is happening now with the existing system. A monitor will enable you to monitor the state of your batteries, measure the effectiveness of your charging system, and track your power usage over time.

A battery monitor will tell you how much DC power is being used; how long it will be until the batteries need recharging at the current rate of use; how much charging current is being produced by the alternator or battery charger; and how much usable capacity remains in the batteries.

Cable, Fuses & Connectors.

To install your electrical or electronics system, or just to fix what's wrong on your boat, you'll need some combination of cables, fuses, bus bars and other components. We can supply the highest quality components at a great savings to you.

This category includes all those products that don't fall into the other main categories but which are needed to complete your on board electrical system.

Hope this help you to get a better idea of what you need, to get your boat up to today's safe and comfortable standards.