Lithium Boat Batteries: LiFePO4 Supply and Fitting

We supply and fit LiFePO4 lithium batteries, including the Fogstar range we sell, and make sure the charging and protection around them are right for the new chemistry.

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Swapping lead-acid for lithium is one of the most worthwhile upgrades on a boat or in a van. A LiFePO4 bank gives you much more usable capacity for its weight, holds a steady voltage as it discharges and accepts charge quickly, so engine running time and solar go further. It is not, however, a like-for-like swap. The chargers, alternator and protection all need looking at.

We sell Fogstar LiFePO4 batteries and fit them, and we will also install another suitable LiFePO4 battery if you already have one, after checking it first. Each upgrade starts with a assessment and a written, itemised quote.

Is lithium right for your boat or van?

Lithium pays off most when you use the batteries hard: nights at anchor, off-grid van trips, running a fridge, inverter or electric cooking. If the boat lives on shore power and the batteries rarely cycle, a good lead-acid or AGM bank may still be the sensible choice. We will tell you honestly which suits your use rather than defaulting to the most expensive option.

Sizing the bank

Because lithium can be discharged much more deeply than lead-acid, a smaller rated bank often delivers more usable energy. We size it from your daily consumption and how many days you want between charges, then check that the battery's continuous and peak current ratings cover the largest loads, such as an inverter or windlass.

Charging and alternator protection

Every charging source needs a lithium profile: the mains charger, the solar controller and the alternator path. Lithium will draw as much current as an alternator can deliver, which can overheat a standard alternator, so we usually fit a DC-DC charger or a regulator arrangement to limit it. The battery management system can disconnect the battery to protect it, and the system must be wired so that a disconnect cannot damage the alternator or leave critical equipment dead.

Safety and installation

A battery bank of any chemistry can deliver enough current to start a fire if a cable chafes or a terminal loosens. We fit appropriately rated fuses close to the battery, secure the batteries against movement and route cables so they cannot rub through. This is not work we recommend doing yourself without experience; a qualified marine electrician should fit or check it.

After fitting we test charging from every source, check the monitor reads correctly and explain what the display should show day to day.

Are lithium batteries good, and safe, for boats?

LiFePO4 is the lithium chemistry generally used on boats because it is more stable than the types found in phones and tools. It gives far more usable capacity for its weight than lead-acid. Safety comes from the installation: a battery management system, correct fusing close to the battery, charging set for lithium and protection for the alternator.

Choosing the best lithium boat battery for your boat

The best lithium marine battery is the one sized to your use, with a BMS whose current limits suit your loads, such as an inverter or windlass. 12V suits most boats; some larger systems run at 24V. We supply and fit Fogstar LiFePO4 batteries and set the chargers to match.

Fogstar battery installation · Boat battery charging · Marine solar panel installation

Frequently asked questions

Which lithium batteries do you supply?

We sell and fit Fogstar LiFePO4 batteries, and we can install other suitable LiFePO4 batteries you already own after inspecting them.

Can I keep my existing charger?

Sometimes. If it has a suitable lithium profile it may only need reconfiguring; if not, we will explain what needs to change before quoting.

Do you fit lithium in campervans?

Yes. We take on campervan and motorhome work as well as boats, and use the same approach to charging and protection.

What is the best lithium battery for marine electronics?

Electronics draw modest current, so most quality LiFePO4 batteries will run them. What matters more is capacity for your use and stable charging.

How do you test a lithium boat battery?

With a battery monitor or the BMS app you can see state of charge, cell voltages and any warnings. A capacity test under a known load shows real usable capacity.

Are lithium batteries safe on boats?

LiFePO4 is the stable lithium chemistry used on boats. Safety depends on a proper BMS, fusing and charging set up for lithium.

Thinking about lithium?

Tell us what you run and how you use the boat or van. We will assess the current setup for free and send a written quote.

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