More and more manufacturers are creating electric boats and hybrid propulsion, but aside from dedicated electric boats, more and more electric outboards are also becoming available. Can you replace your current gas-guzzler with an electric outboard? While the options are still limited, in some cases the answer may be yes. Consider:
Advantages of an Electric Outboard
There are a number of advantages electric outboards hold over gas-powered engines, but which is most important to any individual can vary quite a bit. Some people would consider their zero-emissions environmental friendliness to be a critical aspect, while others might consider this to be a fringe benefit. Others will point to the absence of noise, vibration, and fumes as a huge leg up over internal combustion. Anyone who’s spent time running an electric outboard knows that they’re virtually silent — you’ll hear more noise from the hull lapping against the water than you will from the outboard itself — which simply makes being on a boat more pleasurable. And some people enjoy never needing to fuel up at the gas dock. Not only is this more convenient, it can add up to a financial savings over the long term for those who use their boats often enough. There’s also a cost-savings associated with reduced maintenance, since electric outboards don’t need regular oil or filter changes.
Electric outboards have some unexpected performance and reliability advantages, as well. Since electric motors produce their torque the moment you hit the throttle, they tend to provide much better acceleration and can jump a boat up onto plane faster than outboards that burn fuel. And since you never have to worry about problems with fuel contamination, all those worries about ethanol are a thing of the past. Water contamination and clogged fuel filters are non-issues and you’ll never again have the cruise ruined by an engine bogging down or misfiring.
Disadvantages of an Electric Outboard
There are only a few disadvantages to running an electric outboard, but depending on your situation they can be huge, and for some uses even insurmountable, with today’s technology. The first is the cost barrier. The problem isn’t the motor itself, which is often comparable to the cost of a gasoline motor. The issue is the battery. Electric outboards need a lot of juice, and the cutting-edge batteries needed to power them can drive the cost of an outboard-battery package through the roof. With small models an electric package can double the cost. But in the case of the largest models, it may be five times or even more than the initial cost of a gas motor the same size.
An even bigger and somewhat related issue is range. To get more range you need more batteries, hence driving cost up even more. And no matter how many batteries you pack into a boat, with today’s technology you’ll still never come close to matching the range of a traditional outboard on a planning powerboat. For a sailor looking to replace an outboard that’s only used in the harbor or when the wind dies out, someone who needs to run a tender from the dock to the mooring, or an angler using a small Jon boat on a lake, this may not present a problem at all. But for the average boater the range limitation of using an electric outboard as primary propulsion is often a deal-killer.
Batteries for Electric Outboards
As we just mentioned, the batteries needed to power an electric outboard commonly drive up cost while also limiting range, and for many people are the Achilles Heel of these power systems. But today’s batteries are far better than the ones available just a few years ago.
The critical factor to consider regarding batteries is energy density. A pound of gasoline holds about 300 times as much potential energy as a lead-acid battery, and about 65 times as much as the latest LiFePO4 lithium batteries. On the flip side of the coin, electric motors are usually around twice as efficient as internal combustion engines. So, when all is said and done, in round figures an electric motor linked up with the best batteries we have readily available today will need to haul around 32.5 pounds of batteries to generate as much power as a pound of gas.
Another issue with batteries is that many manufacturers of electric outboards don’t make them. Instead, they sell their motors and leave it up to you, the boater, to figure out how to provide the juice. This can be confusing to say the least. In recent years this has changed a bit and fortunately now some manufacturers are designing outboard to run with specific power packs. In the case of small outboards, several are making dedicated batteries that clip onto the outboard itself and look more or less like an outboard cowl. One of the latest includes a drop-in slot for batteries in the top of the motor. Manufacturers have identified battery issues as one of the main barriers to selling electric outboards and as time goes on, we can expect options with the outboard and dedicated batteries sold as packages to continue to expand.
Electric Outboards Available Today
There are a number of small electric outboard manufacturers, a handful of large companies producing electric outboards, and in recent years a couple of the marine industry’s leading companies have also begun producing outboards fueled by electricity rather than gasoline. You can find some (as well as several companies that have come and gone in recent years) that don’t appear below, but the big players include:
Founded in 1890, Elco is the oldest manufacturer of electric powerplants for boats in the country and has been building electric outboards since 1950. Today they build 5- to 50-hp electric outboards compatible with both tiller and remote-controls (as well as inboard motors to 200-hp). However, remote control and battery options are fulfilled by third-party options.
A very wide range of electric outboards (as well as electric inboards, pod drives, and even a SUP motor) are produced by ePropulsion. Outboards range from three to 9.9 horsepower, all of which are designed for specific battery/charger packages ranging from 1- to 9-kWh. Three-hp models come with a clip-on battery that mounts at the top of the shaft. Both tiller steer and remote-control options are available. ePropulsion is also the only electric outboard that can hydro-generate electricity to feed power back to the batteries by “feathering” the prop (allowing it to spin) while a boat is under sail. We’ve had extensive testing with the Spirit 1.0 Plus three-hp model mounted on a small fishing boat (the green and tan Sun Dolphin previously pictured), and found it ideal for fishing in lakes and ponds where a range of 20 or so miles is more than enough. The pleasure of operating a reliable outboard with no noise or fumes is a fantastic benefit, and the motor’s stealthy nature is an added bonus when trolling in shallow waters for spooky fish.
With both inboard and outboard offerings, Evoy currently produces a single outboard that they rate at “120-plus-hp.” It’s packaged with 63-, 126-, or 189-kWh batteries and has the distinction of also offering an app that allows for monitoring charge state, trip logs, GPS data, and more. Evoy says they have 200-plus, 300-plus, and 400-plus horsepower engines under development with all expected to be available during 2024.
A newcomer that just recently appeared on the scene, Flux Marine is now offering pre-orders on three electric outboards which it says will be ready in the summer of 2023. They come in 15-, 40-, and 70-hp versions and are available with modular battery packs with integrated management systems. Although we have yet to see the real-world products from this company, in 2022 it announced securing $15.5 million in funding for development and manufacturing, so this is a company to keep an eye on.
Mercury Marine initially showed their Avator 7.5e electric outboard concept at the 2021 Miami International Boat Show, and we were able to tank-test a prototype at the end of 2022. Production models are expected to hit the market this year. Mercury has developed a unique 1-kWh drop-in battery that slides into the motor’s cowl and produces “similar speed and acceleration as Mercury’s 3.5-hp FourStroke,” according to the company. Tiller steer and side- or binnacle-mount remote controls with a digital display will also be available. Mercury says that later in 2023, an Avator 20e and 35e will be released.
Pure Watercraft manufactures the “Pure Outboard” system which consists of an outboard rated to produce the equivalent of 50-hp. It can be purchased with one or two 8.85-kWh lithium-ion battery packs as well as remote controls. The motor itself weighs 112-pounds, produces 25-kW, and comes with a three-bladed 16” prop.
Torqeedo is one of the best-known and most well-established makers of electric outboards, producing the widest range on the market today including 1- to 80-hp motors (as well as inboards, sail drives, and a pod drive). Tiller and remote-control options are available for a wide range of their products. Torqeedo models up to 3-hp have clip-on batteries, with fully integrated battery/battery management/charging packages available for all of their offerings. The largest, the 80-hp Deep Blue, matches up with a 350-volt, 38-kWh prismatic-cell lithium-ion battery developed in cooperation with BMW, and based on the battery for the BMW i3.
Vision marine makes electric boats and has a single outboard offering, the 180-hp 180E. It’s packaged with a 70-kWh power-pack that Vision says is scalable, as well as controls, a touchscreen interface, and a battery management system. However, Vision is currently selling to OEM manufacturers only, so these outboards are not available for repowers or retrofits.
Outboard manufacturing giant Yamaha Marine more or less entered the electric outboard market in 2021 when they announced the 9.9-hp Harmo system. We say “more or less” because the 121-pound Harmo doesn’t have an outboard’s motor mount, but instead bolts flush to a boat’s transom and has a look similar to that of a stern drive. However, Yamaha says the Harmo can be mounted to most outboard-like applications including transoms and motor brackets designed for outboard power. Yamaha began shipping the system this year, but says that for the time being it will installed only as a package on new boats and won’t be available on an aftermarket basis.
The Future of Electric Outboards
So, will your planing powerboat one day be powered by an electric outboard? The chances are very good that the answer is yes, but as to just how far off into the future that may be is anyone’s guess. The big variable will undoubtedly be batteries, and how long it takes to develop better energy density.
Until that time arrives, however, electric outboards have already surpassed gas power for many low-horsepower, short range applications. Their numerous advantages make them ideal for powering small boats used on lakes and ponds where ranges of more than a couple dozen miles aren’t necessary. They work great as auxiliary power for sailboats. Electric outboards are ideal for short-haul use on tenders. And they even have a place in low-speed commercial operations like water taxis, where over time enough fuel gets saved that the initial investment can be recouped.
For many boaters, the question probably isn’t if you’ll ever own an electric outboard — it’s more a question of when.