Best Electric Outboard Motors

Electric Outboard Buyer’s Guide

Boating means something a little different to every boater. For some, it’s a chance to enjoy the peace and quiet of being on the water. For some, it’s simple transportation, getting from Point A to Point B as painlessly as possible. And for others, getting on the water means quenching their need for speed, be it on a jet ski (like the Taiga Orca electric) or maybe a Lamborghini Boat.

Sifly has used their electric propulsion system developed for their efoils and attached it to a mini-cat PWC, illustrating that there are some very interesting projects in the works out there.

Not all of these boaters will happily fit into an electric future, just as not all automobile owners now drive Teslas. But electric outboards are here, and what they offer is astounding compared to the alternative.

Currently, the best case for an electric motor is made at the small end of the scale. Battery technology currently allows for a very practical three-horsepower-equivalent motor. These 1 kW outboards have been around for over a decade and have proven reliable, even preferable to their gas counterparts.

But there are some promising, power options, like the Evoy Storm on the Axopar below.

These motors cost more than gas motors of the same size but require no maintenance or fuel. And there are many other benefits. For example, they are smaller and lighter, easier to transport and store, and lack the fickle carburetors that are always clogging on gas outboards of this size.

However, outboards larger than five horsepower are still prohibitively expensive for most and rare to see in the wild. Several companies are producing them, but the battery and charging technologies needed to keep them running are only now catching up.

Luckily, many new companies are tackling the problem every year, and you’ll likely see electric boats zipping around shoresides everywhere within the next decade.

How Much Power Is Enough for an Electric Boat Motor?

Electric boat motors do not produce horsepower, at least not measured like gasoline engines. Instead, their power output is measured in watts. This makes it a little cryptic for the layperson to figure out what they’re looking at when comparing a 1 kW outboard versus, say, a 9.9 horsepower gasoline outboard.

Most manufacturers will provide an equivalent horsepower number, but these are just for comparison purposes. Depending on how the motor is geared and propped, it might produce more torque than a gas outboard and perform better than you’d expect with a similar-sized gas outboard. Due to all these variables, horsepower equivalents are tricky.

Here’s a table of horsepower-to-watt equivalents. From a math standpoint, you find horsepower by dividing watts by 745.

Converting horsepower to watts to see how electric power translates into traditional power.

Unfortunately, manufacturers’ ratings aren’t very clear in watts, either. There is a difference between how many watts of electricity you can put into a motor and how many are converted to move the boat. That efficiency sets some motor manufacturers apart and can make two competing 1 kW motors act very differently in the real world.

Output is usually measured in “propulsive watts” or sometimes by measuring the push of static thrust in pounds.

It’s Not the Motor, It’s the Battery

The motor gets you moving, but the battery bank keeps it running. In gasoline terms, your battery is your fuel tank. It determines how long you can keep the prop spinning. The phenomenon known as range anxiety for drivers learning the limits of their electric cars counts on the water too.

In terms of technology, the trick is not in the outboard motor itself, similar to cars, it’s in the battery. Electric motors have been around for a long time, and making one into an outboard isn’t a big deal. What is a big deal is having a battery that can run it for any time while taking the high power draw you need to go fast.

Various lithium battery technologies are up for the challenge, but it’s a developing technology.

Automobiles have only just gotten competitive with gas. But it’s important to remember that an outboard motor is often driven at 80-90 percent power for long periods, while cars typically only run at 30 or 40 percent while on the highway. That’s a big difference in what the battery has to be able to provide.

For electric outboards up to 3 horsepower (1 kW class electric outboards), the battery is sometimes integrated into the motor–like the Torqeedo–to make an easily portable package. This also gives the consumer an easy-to-understand cost of installation. You pay one price and get everything you need.

Anything more powerful requires an external battery bank mounted somewhere else in the boat. This is the same situation as with gasoline outboards. Portable models have small, built-in fuel tanks, while large gas guzzlers have tanks built into the boat.

But building a battery bank in the boat is no trivial matter. You need space to mount it and the capacity to hold the weight of it. Then you ask, how many volts does the motor operate off of, how many amp-hours of capacity do you need for the range you require, and which battery chemistry is most appropriate? Once you have decided on the batteries, you must build in their support systems, wiring to run the motors, charging controllers to top them off when at the dock, and monitoring and safety systems to ensure they are not under or overcharged.

You can spend much more on the battery system than the outboard itself. Lithium batteries are expensive. For example, both Torqeedo and ePropulsion sell their 1 kWh portable battery packs for about $1,000US. In other words, for the cost of the battery alone, you’ve already spent more than you would on a new gas outboard of the same size.

For example, Elco Motors suggest using 2 lithium batteries to power their inboard 20 horsepower motor. That’ll run $13,000, or there abouts in 2023.

Thankfully, battery technology is evolving quickly, and the prices are decreasing. New outboard manufacturers are tackling the problem by building and selling their own battery kits, as with Mercury Marine’s Avator 25e and 30e and the Pure Watercraft outboard system with stackable batteries.

Other companies, like Torqeedo, are partnered with electric auto companies to marinize existing car batteries. Beyond partnerships, Yamaha’s purchase of Torqeedo in 2024 will give the latter access to more engineering resources. Torqeedo already uses BMW i-series battery packs for their high-power Deep Blue installs.

Going beyond this, the Axopar x Evoy partnership on the AX/E 25 shows the growing power of these engines. As we see on electric boats (read about them here) in general, much is happening that requires both boat manufacturer and engine company to cooperate. But when they do, it pays.

Electric Boat Motor Charging

Where’s your nearest electric boat charging station? You’ll probably be looking for a while because they don’t exist yet.

One advantage that electric boat motors have over their automobile counterparts, however, is the presence of high-amperage power outlets. Nearly all marinas have options for 30, 50, or 100-amp shore power connections. For the makers of these boats, that presents an opportunity for fast chargers with existing infrastructure.

In essence, it’s easier for most boat owners to make their own electric boat charging station at their marina slip than for homeowners to do the same in their garages.

Advantages and Disadvantages Compared to Gas Outboards

Here’s a look at some pros and cons of going electric on your boat.

Advantages of Electric Outboard Motors

• Near silent operation
• Smooth operation with no vibration
• No fumes or smoke, zero direct emissions
• More torque and faster response than gas outboards
• Easier to start, push a button and go
• Portable models are lighter and easy to store and transport
• Many motors are modular, making them even smaller and lighter to carry
• Almost no maintenance is required for the motor
• Some brands have been in business for more than a decade with proven products
• Currently available from 1 to 80 horsepower, higher power models coming soon

Disadvantages of Electric Outboards

• Most exciting options are from new startups with no track record
• New technologies haven’t been thoroughly tested for marine life
• High-powered options are pre-order only
• High motor cost
• Extremely high battery cost
• Battery longevity concerns coupled with replacement cost
• Batteries of sufficient capacity for high-power applications are large and heavy
• Long recharge times and limited power for fast charging at docks, lack of electric boat charting station locations

Is An Electric Outboard Right For You?

Currently, high-powered electric outboards (anything more than about ten horsepower) are for early adopters only. There aren’t many options out there, and those are pricy.

However, if you’re in the market for a small, portable outboard, then 1 kW electric outboard motors have proven to be an outstanding alternative to gas. They run nearly silent, require next to no maintenance, produce zero direct emissions, and start with the push of a button. Plus, you’ll never have to clean another clogged carburetor again. Hallelujah!