Narrowboat Electrician: Living-Aboard Power Systems

A narrowboat electrician deals mainly with the domestic side of the boat: the leisure battery bank, charging from the engine, solar and shore hook-up, the inverter, and the 12-volt and 230-volt circuits that run a boat people often live on. That is the same work we do on coastal boats, and we take on narrowboats and other inland craft when they are within reach of our area.

Narrowboats put unusual demands on their electrics. Many are lived on full time, which means a fridge, lighting, water pump, laptops and sometimes a washing machine running every day, often while the boat is moored away from any hook-up. The electrical system has to cover that demand from batteries, then refill them from the engine alternator, solar or a generator.

We are based in Lancing and work on the coast from Brighton to Southampton. Inland boats near that area are welcome; if you are further afield, we would rather tell you so straight away than make promises we cannot keep.

Sizing the battery bank for life aboard

The starting point is a daily energy budget: list every appliance, how much power it draws and for how long, and add it up. From that you can size the battery bank so it covers a day or two without dropping too low, and size charging so it can put that energy back.

Lead-acid banks should only be used through roughly half their capacity if you want them to last. Lithium iron phosphate (LiFePO4) can be used much more deeply and accepts charge quickly, which suits boats that cruise for a few hours and then moor. We supply and fit Fogstar LiFePO4 batteries among others, but a lithium bank needs its charging sources and protection set up for it, not simply dropped in.

Charging: alternator, solar and hook-up

Most narrowboats rely on the engine alternator as the main charging source while cruising. With lithium, the alternator usually needs protecting from the high currents the bank will accept, typically with a DC-DC charger or an alternator regulator designed for it.

Roof solar is a natural fit on a long, flat cabin top and can keep a moored boat topped up through much of the year. We fit MPPT controllers and match the panel layout to shading from trees and bridges. At a marina or winter mooring, a shore hook-up with a proper inlet, RCD protection and a good charger does the rest.

Inverters and 230-volt circuits

An inverter lets you run mains appliances from the batteries. Sizing it correctly matters: too small and it trips on start-up loads, too large and it wastes energy and needs heavier cabling and fusing. Many owners choose an inverter-charger such as a Victron unit, which combines the inverter, battery charger and shore power transfer in one.

Any 230-volt system on a boat must be installed with correct earthing, RCD protection and separation from the DC side. This is not a job for guesswork.

Boat Safety Scheme and inland rules

Inland boats in the UK are usually subject to the Boat Safety Scheme examination, which includes electrical checks such as battery security, cable condition and circuit protection. We can check and correct electrical items before an examination, and our guide to BSS electrical requirements explains what examiners look at.

Common narrowboat electrical faults

The problems we hear about most are:

Frequently asked questions

Do you work on narrowboats?

Yes, when they are within reach of our coastal area from Brighton to Southampton. The domestic electrical systems are the same kind of work we do on sea-going boats.

Can I just swap my lead-acid batteries for lithium?

Usually not without other changes. The alternator, charger and solar controller all need to suit lithium, and the bank needs appropriate protection.

How much solar does a narrowboat need?

It depends on your daily use and the season. We work it out from an energy budget; winter output is far lower than summer, so most liveaboards still need another charging source in winter.

Can you help before a Boat Safety Scheme examination?

Yes. We can check the electrical items examiners look at and correct any problems beforehand.

Planning narrowboat electrics?

Tell us where the boat is and how you use her, and we will tell you honestly whether we can help.