Narrowboat & Widebeam Electrical Systems:

What Should a Modern Boat Have?

The electrical system is one of the most important parts of any modern narrowboat or widebeam.

As expectations have changed, boats are increasingly expected to provide many of the conveniences of a home: induction cooking, televisions, refrigeration, washing machines, Wi-Fi, lighting, charging points and other everyday appliances.

But supplying those loads reliably on a boat requires much more than simply fitting a large inverter and a bank of batteries.

A properly designed marine electrical system needs to consider how much energy will be used, how quickly it can be replenished, how the batteries are monitored, the available shore-power supply and how all of the components work together.

At Central Boating, we design the electrical system around the vessel and how its owner intends to use it.

12V vs 24V Boat Electrical Systems

Most traditional narrowboats use a 12V DC system, and for many vessels this remains perfectly suitable.

On larger widebeams with greater electrical demands, a 24V system can offer advantages. For the same amount of power, increasing the system voltage reduces the current flowing through the DC side of the installation.

This can be particularly useful on larger vessels with powerful inverters, substantial battery banks and higher electrical loads.

At Central Boating, our typical approach is:

Narrowboats – 12V DC systems

Widebeams – 24V DC systems

However, every electrical specification should ultimately be designed around the requirements of the individual vessel rather than simply following a standard template.

Lithium Batteries

Battery technology has developed considerably in recent years, and LiFePO4 lithium batteries have become increasingly popular for modern liveaboard and leisure boats.

Compared with traditional lead-acid batteries, lithium batteries can provide greater usable capacity, reduced weight and significantly improved charging performance.

For owners wanting to run equipment such as induction hobs, washing machines or other high-demand appliances away from shore power, a properly designed lithium system can make a substantial difference.

Battery capacity is only one part of the equation, though.

The charging system, inverter, alternator arrangement, solar installation, protection and monitoring all need to be designed to work together.

Inverters: Bringing Mains Power Aboard

An inverter converts the boat's DC battery power into the 230V AC supply required by conventional household appliances.

Modern boats can have considerable AC requirements, which is why inverter sizing matters.

A system needs to account not only for the normal running consumption of an appliance but also the possibility of several appliances operating simultaneously.

Our new-build specifications typically use Victron Energy inverter/chargers, with systems appropriately sized for the vessel and its intended use.

A typical Central Boating specification may include:

3kVA inverter/charger on a narrowboat

5kVA inverter/charger on a widebeam

The final specification is determined by the expected electrical loads aboard the vessel.

Solar Power

Solar is one of the most useful additions to a cruising boat, particularly during the brighter months.

A correctly sized solar array can help replenish energy consumed by refrigeration, lighting, pumps, entertainment systems and other background loads without requiring constant engine running or shore power.

Solar panels are normally connected through an MPPT solar charge controller, which manages the energy being supplied to the batteries.

The amount of solar that can realistically be installed depends on available roof space, the vessel layout and equipment such as skylights, mushroom vents and other roof fittings.

This is why solar should ideally be considered during the original boat design rather than added as an afterthought.

Battery Monitoring

One of the biggest benefits of a modern electrical installation is being able to actually understand what the system is doing.

Good battery monitoring allows the owner to see information such as battery state of charge, current consumption and charging performance.

Depending on specification, our systems can incorporate equipment such as Victron SmartShunt and Cerbo GX monitoring.

Rather than guessing whether the batteries are getting low, the owner has meaningful information about the condition and performance of the electrical system.

Shore Power and Charging

When connected to a suitable marina shore supply, the boat can use external 230V power while simultaneously charging its battery bank through the inverter/charger.

However, shore-power availability varies between moorings.

The electrical system therefore needs to account for the limits of the shore connection rather than assuming unlimited mains electricity is available.

For liveaboard vessels in particular, understanding this relationship between shore power, battery storage, inverter capacity and onboard demand is important.

Can You Have an All-Electric Narrowboat or Widebeam?

Increasingly, yes — particularly when talking about the domestic equipment aboard the boat rather than propulsion.

Induction cooking, electric ovens and other household-style appliances can all form part of a modern boat specification.

But an all-electric domestic setup needs to be designed properly.

Simply adding more batteries isn't necessarily the answer. The complete system needs sufficient storage capacity and a realistic method of putting that energy back into the batteries.

The owner's cruising habits also matter. A vessel spending most of its time connected to shore power has very different requirements from one continuously cruising and spending long periods completely off-grid.

Why Electrical Systems Should Be Designed Early

Electrical design shouldn't begin after the boat has already been fitted out.

Cable routes, battery locations, solar capacity, inverter positioning, ventilation, isolation, protection, appliance loads and future accessibility should all be considered during the design and first-fix stages.

It also allows the electrical specification to be coordinated with the cabinetry, plumbing, heating and general layout of the vessel.

This is particularly important on bespoke builds where owners may have significantly different requirements.

Building a System Around the Owner

There isn't one perfect electrical specification for every narrowboat or widebeam.

Someone using their boat occasionally at weekends has very different requirements from a couple living aboard full-time.

That's why at Central Boating, our electrical specifications are designed around the boat and its intended use.

Our modern new-build packages can incorporate Victron inverter/chargers, LiFePO4 battery storage, solar charging, system monitoring and carefully designed 12V or 24V installations, providing owners with a practical electrical system designed for modern boating.

Whether you're planning a narrowboat for extended cruising or a widebeam intended for full-time living, considering the electrical system early in the design process can make a major difference to how the finished boat performs.

Planning a new narrowboat or widebeam?

Take a look at our New Builds & Pricing page to see our current specifications and guide prices, or contact Central Boating to discuss the electrical requirements for your own build.