Inverters

Best Power Inverter for Boats and Marine Use 2022

By:Michael Johns

Marine power inverter for boat

Looking for a marine power inverter for your boat?

Well, you’re in the right place.

If you’re living on a boat, a reliable inverter is absolutely essential.

It is the heart of your electrical system which enables you to run all your appliances and keep electronics charged up.

The trouble is that there are lots to consider when choosing a new inverter.

And if you get it wrong, life becomes incredibly frustrating.

Without the right size and functionality, an inverter can be almost useless!

That’s why I’ve written this easy to understand guide to help you through any problems.

Together we’ll look at what size marine inverter you need, features to consider, and the best products available today.

Check the top picks…

What is a Power Inverter Used for in a Boat?

A marine power inverter is used to convert DC electricity from a battery into AC electricity that appliances need to run.

When away from shore, you’ll need your inverter to draw power from your deep cycle batteries. Without an inverter, you won’t have an electricity supply.

What’s handy, is that many marine inverters have in-built chargers and transfer switches. This means when you’re hooked up to shore power, it will automatically use this to charge your batteries and run your electrical system. Then when you unplug and set sail, the inverter then starts to draw energy from your batteries.

What Size Inverter for Boats?

You will need at least a 500 watt inverter for a boat, and many people go for much bigger than this size.

It all comes down to what appliances and electronics you want to run from your inverter and batteries.

For example, if you just need to run some lighting, charge phones, and run a mini fridge then you won’t need much more than a few hundred watts.

On the other hand, if you want to run items like hairdryers, tools, microwaves, or coffee machines then you will need a 2000 or 3000 watt inverter.

To work out what size inverter you need simply add up the wattage of all your appliances and add 20%. This will give you the minimum capacity inverter you require. Remember, inverters are not 100% efficient as they lose energy during the conversion on DC to AC. 

For example, a 1000W inverter will not run a 1000W appliance. You need to add 20%, so a 1200W inverter is needed for a 1000W appliance.

Types of Inverters for Boats

Before we look at the top products, let’s discuss the different types of inverters available.

Normal Inverter

A regular inverter has one function. It simply draws energy from the battery and converts it into AC electricity to run your appliances. I can’t recharge your batteries in any way.

Inverter Charger

Inverter chargers do everything a normal inverter does, but it also has a built-in battery charger. This allows you to charge your deep cycle batteries via mains shore electricity hook up. You will need a battery charger so many people like this automated option.

Best Power Inverter for Boat Reviews

Let’s take a look at the best marine inverter for boats available today. All the products discussed below offer brilliant performance, quality, durability, safety, and essential features.

AIMS Power 1000 Watt Pure Sine Marine Inverter Charger

At the top of the pile is an inverter charger that does it all. This is the only piece of kit you really need to hook up your batteries and shore power into your electrical system.

We’re looking at the 1000 watt model here, but you can also get it in 600 watts or up to 3000 watts depending on your needs.

Here you’ll be getting 1000 watts continuous output and 3000 watts peak power for 20 seconds. So you shouldn’t have any trouble switching on appliances. 

To run your appliances there’s 2 GFCI AC outlets. Plus an AC terminal block allows you to easily add a shore power connection in order to charge your batteries while supplying your boat with electricity. 

An automatic transfer switch means there’s no faff. You’ll draw shore power when connected and instantly switch to battery energy when disconnected. A 35A in-built charger gives you pretty decent recharge speed too.

Of course, it has all the essential safety features to guard against overload, overheating, and short circuit. Although, be careful not to wire it up wrong as reverse polarity could cause instant damage.

An all-in-one inverter charger for your boat.

Pros:

  • Inverter charger
  • Pure sine wave
  • Automatic transfer switch
  • 35A charger
  • 2 GFCI outlets

Cons:

  • No screen
  • No USB

Xantrex Prowatt 2000W True Sine Wave Inverter for Boats

If you’re looking for a regular inverter, then the top slot goes to the Xantrex Prowatt.

It is compact and pretty lightweight while pumping out a serious level of power! A yes, true sine wave, is the same as pure sine wave before you get confused.

Enjoy 2000 watts output to run electricity to your whole boat. That’s plenty to run most small to medium sized appliances. You could even fire up a microwave or coffee machine.

You’ll love how effortless it is to operate. Once hooked up to your batteries, simply hit the power switch and plug in. There’s 2 AC outlets with a resettable fuse to keep your electronics protected. 

In addition, you can keep on top of your power output with live reading from the digital screen. Easily install and mount the Xantrex to get your power up and running quickly.

Pros:

  • Pure sine wave
  • 2000W
  • Easy to use
  • Easy installation
  • 2 AC outlet
  • Digital screen

Cons:

  • No USB
  • No charger or transfer switch

Xantrex 806-1020 Inverter Charger for Marine Use

Xantrex excels when building inverters to use on a boat. This is another option with an in-built battery charger. To be honest, it’s a toned-down option compared to the AIMS inverter charger we started with.

You still get all the essential components for a great marine inverter charger including 1000 watts capacity.

It’s a cheaper option as you are getting modified sine wave rather than pure sine wave. This means you can still run plenty of appliances including resistive loads like toasters, hairdryers, kettles, heaters, along with charging phones and laptops. But you’ll struggle to run inductive loads like refrigerators, AC, motorized tools, and microwaves. Plus delicate electronics like medical equipment or LED TVs won’t enjoy this output.

The inverter function works absolutely brilliantly for most situations. In addition, the in-built charger supplies 30A to your batteries. The electricity draw is taken care of with an automatic transfer switch to move between shore and battery power instantly.

A solid inverter charger at a great price.

Pros:

  • Inverter charger
  • 30A recharging
  • 2 AC outlet
  • LCD screen
  • Good price
  • Auto transfer switch

Cons:

  • Modified sine wave
  • No USB
  • Screen is small
  • Mounting a little fiddly

GoWISE Power 1500W Pure Sine Wave Power Inverter

When I talk about power inverters, GoWISE always seems to enter the equation. Its products always deliver a nice balance of features and durability.

For your boat, you might consider this 1500 watt unit. You’ll be getting a well-built piece of equipment with a ribbed metal shell for durability and heat dispersion. Plus the power output is smooth pure sine wave to run any type of appliance.

It’s super easy to hook up to your batteries. Then simply plug your electronics straight into the 3 AC outlets while charging your phone from the USB port. The only thing missing is a hardwire terminal but that might not be a concern for you.

A wired remote means you can power on effortlessly, handy if you want to mount the inverter out of the way. And a 3000 watt surge capacity makes switching on new appliances a breeze.

As regular inverters go, this one is hard to beat.

Pros:

  • Pure sine wave
  • Durable design
  • 3 AC outlet
  • USB port
  • Easy to use
  • Remote switch

Cons:

  • No screen
  • No battery charger
  • No hardwire terminal

Go Power! Pure Sine Wave Inverter Charger

Keen to get yourself some beefy power in your boat to run tools, heaters, and more? Then this beast is for you.

Let me reel off the stats for you:

  • 2000W continuous output
  • 100A charger
  • 90% efficiency
  • 3400W surge capacity
  • 100A transfer switch

As you can see, it’s got all the features of a top inverter charger with high capacities. It’s simple to install and then you can leave it to do its thing. Draw shore power and charge your batteries quickly until you set sail. Then your inverter instantly takes over with your battery energy. 

Adding to this, you get a remote control with a digital display for live power readings and charge status. To top it off, you’re covered by a chunky 3 year warranty, which is confirmation of a well made product.

Pros:

  • Pure sine wave
  • 100A charger
  • Transfer switch
  • Remote with screen
  • 2000W

Cons:

  • Expensive
  • No USB or 3-pin AC outlet
  • Heavy

Renogy 2000 Watt Pure Sine Wave Power Inverter

The Renogy 2000W inverter is one of the best sellers and is used in a wide range of scenarios for off-grid power. This includes boats!

You get a powerful 12V DC to 120V AC pure sine wave output, plus a 4000W peak surge capacity. It’s an easy to use no-fuss inverter. You can quickly hook up the positive and negative input terminals to your battery. Then run your appliances via 3 AC outlets. USB port, and a hardwire terminal.

There’s no screen but clear LED indicators give you feedback on the current working status. Plus a wired remote switch means you can power on effortlessly.

Of course, all the important safety features mean you can sleep comfortably at night, and smart fans keep things cool as a cucumber.

Easy to use, no-fuss, and high performance.

Pros:

  • Pure sine wave
  • Easy to use
  • Wired remote
  • 3 AC, USB and hardwire terminal
  • Smart cooling fans

Cons:

  • No screen
  • No charger function
  • No transfer switch

BESTEK 500W Pure Sine Wave Power Inverter

Don’t need so much power? Then this 500 watt unit still delivers exceptional performance.

This inverter from BESTEK is one of the best options around when looking for a lower powered inverter. 

It offers awesome versatility and is even small enough to be portable. You could use this as easily in a car as in a boat. On arrival, you can hook it up in seconds using the supplied alligator clips. Plus you can take it with you in the car using the cigarette lighter plug.

In terms of performance, you’re still getting ultra smooth pure sine wave electricity which you can access via 2 AC outlets and 2 USB ports. With 500 watts you could easily run a TV and games console while charging a smartphone.

All the time, you’re protected from overload, overheating, voltage fluctuation, and short circuit.

Small but powerful!

Pros:

  • Portable
  • Pure sine wave
  • Use anywhere
  • 2 AC and 2 USB
  • Easy to use

Cons:

  • No screen
  • Limited power
  • No remote
  • No charger or transfer switch

Factors to Consider When Buying a Marine Inverter

By now you should have a good idea of what sort of products are available. 

If you’re still a little confused about what to choose, then keep reading. Next we’ll go through the various factors to consider when making your final choice. These are the elements I look at when selecting the best boat inverters.

Pure vs Modified Sine Wave

You might have noticed that there’s two different types of electricity that inverters produce – pure sine wave and modified sine wave.

Pure sine wave is the better of the two choices but a little more expensive. Pure sine wave more closely replicates the smooth electrical current you get from the main grid. The benefit is that you are not restricted in the type of appliances you can run. You can happily power sensitive electronics like medical equipment, demanding AC motors like power tools, and inductive loads like compressors, refrigerators, Air-con, and microwaves.

Modified sine wave is cheaper but you can’t run the most sensitive electronics, motors, and inductive loads. If you just plan to run resistive loads like heaters, hair dryers, toasters, along with other basic electronics you’ll be fine. Plus you can still charge phones, laptops, and tablets.

Personally, I always go for pure sine wave so you don’t have to worry about what you can run on your boat.

Voltage

The input voltage of your inverter must match the voltage of your battery. For example, you must use a 12V inverter with a 12V battery. You must never mix voltage of equipment, so don’t try to run a 12V inverter from a 24V battery etc.

If your inverter detects the wrong voltage it will usually shut down to protect itself. It simply will not work.

Inverter Charger

If you want an inverter that can charge your batteries from the mains then you’ll need to go for an ‘inverter charger’. These units have a battery charger component built-in and it saves having separate battery chargers. 

The size of the in-built charger is measured in amps. You will find they have between 30 – 100A current capacity. The higher the number the more powerful and faster the charging will be.

Automatic Transfer Switch

Inverter chargers also have functionality known as an automatic transfer switch. This allows you to hook up your equipment to shore power. When connected to shore power your inverter will automatically draw mains electricity to run your appliances and charge your batteries. When you disconnect, it instantly switches to draw energy from your batteries. This is super useful, and means everything works automatically without your intervention.

Outlets

Generally, you’ll find three different types of outlets on an inverter. Normal 3-pin AC plugs, USB ports, and hardwire terminal blocks.

3-Pin AC Outlet – This is the same style socket you get in the wall at home. You can quickly plug your appliances straight into the inverter.

USB Port – Draw power to USB devices like smartphones and tablets.

Hardwire Terminal Block – You can directly wire your boat electrical system to the inverter in order to draw full power through this single terminal. Most useful on more powerful inverters above 1000W.

Safety

You should never compromise on safety. Inverters are part of high powered circuits that can even be connected to mains electrical supply. All of the inverters discussed above offer the essential safety features. Without these protections your appliances and personal safety are at risk. For example, if your inverter overheats it can melt and catch fire!

Please ensure your inverter is protected against overload, overheating, overvoltage, undervoltage, and short circuit.

Adding to this, you can get extra features such as audible alarms, smart cooling systems, and reverse polarity guards.

Price

So how much does a power inverter for a boat cost?

Well, you can expect to pay anywhere between $200 to $1000+. As you can appreciate, it depends on the power and functionality of the inverter. For example, a normal inverter with 1000W capacity can cost around $200. But a larger inverter charger with a transfer switch can cost over $800.

One thing I will say is – buy cheaper, buy twice. That means if you try to cut costs and buy a cheap inverter then don’t expect it to last long. Plus it might not be able to do the job you need it for. So by choosing a cheap inverter, you might have to buy another one when you’re let down.

Other Features

Here’s a list of features you find on inverters:

  • Digital screen
  • Remote control
  • Bluetooth
  • Wireless charging
  • In-built charger
  • Transfer switch
  • Mounting plates
  • Carry handle
  • Alligator clips
  • Aluminum shell
  • Smart cooling

How to Install a Power Inverter in a Boat

You can easily install a power inverter in your boat on your own. Here’s a helpful video to explain the process:

FAQ About Marine Inverters

Here’s the answer to your most common questions.

How long will a marine battery last with an inverter?

The runtime of your battery with an inverter comes down to the size of battery and energy used by appliances. You should add up the total amps (A) pulled by your appliances and compare it to your battery capacity in amps-hours (Ah).

For example, if your appliances use a total of 70A and you have a 300Ah battery, it would last for 4 hours 15 minutes.

Can you use a power inverter on a marine battery?

Yes, you can easily use an inverter with a marine battery. It is the best way to convert the battery DC energy into AC electricity you need to run most appliances. You should check the type of marine battery (Gel, AGM, Flooded, Lithium, etc) and ensure your inverter is compatible.

Where do you put an inverter on a boat?

You should install your inverter as close to the batteries as possible. Most inverter cables are 3ft in length, and you should try not to exceed 10ft between inverter and battery. 

The further away your inverter is from your battery the more resistance you’ll get in your cables. If this happens you will need to change your wire gauge to avoid loss in voltage.

Final Words on Marine Inverters for Boats

You should be in a much better position to choose the best power inverter for your boat.

We’ve talked about whether you need a regular inverter or an inverter charger with an in-built battery recharge.

I would also always go for a pure sine wave output so you’re not restricted on what you can run. Then the rest of the features come down to how you will use your equipment.

You can confidently choose from the products discussed in this article which deliver top quality performance.

Looking for even more power in an inverter? Then take a look at my guides to 4000 Watt and 5000 Watt Power Inverters.

Thanks for reading and happy sailing.