Let’s all take a moment and give thanks to electric car manufacturers. They’re the reason for a surge in interest in electric-powered boats. That’s good news for cottage boaters (and for our neighbours and wildlife) who want a quieter, more peaceful on-water experience or who want to reduce their contribution to nasty emissions, oil, and other pollutants in the lake.
If you’re daunted by the prospect of learning the new technology, don’t be. Whether you want to convert an existing cottage boat or you plan to fit your next new boat with electric power, start by asking yourself a few basic questions, says Dean Heinemann, the director of sales at New York-based Elco Motor Yachts, which is a pioneer in electric marine propulsion and classic electric launches. First, what kind of boat do you have and how fast do you want to go? This will determine the size of motor you need. Second, how far do you want to go without recharging? Your answer will dictate the number and size of batteries you require. Add a charging system for your setup, connect all the components together, and you’re ready to cruise.
The motor: How fast do you want to go?
The faster you go, the more power you will need. To determine how fast your boat can go, consider its hull shape:displacement or planing. Displacement hulls (the round bottoms of canoes, motor launches, and large sailboats are good examples) are designed to cut through the water smoothly and push it aside with little effort. Planing hulls (V-hulled ski boats, for example) will lift out and skim on top of the water, but to get up on a plane they require an increase in power. For planing boats, weight, which is always a consideration in boat design, becomes a bigger issue.
“One of the nice things about converting boats to electric, as opposed to cars, is that the weight of the boats is not as big a factor in performance because there are no hills to go up,” explains Jonathan Killing, of Toque Innovations in Midland, Ont., who has worked on a number of design projects involving electric motors. “But when you get into planing boats, you make your own hill getting up onto plane, so weight becomes a huge factor.” A planing boat needs more than a burst of power to climb up that big bow wave; the motor also needs to run at a higher speed to hold the boat there.
“You need to realistically look at how you boat and decide if electric can fit into that,” says Mary Jo Reinhart, the director of OEM and retail sales for the electric motor manufacturer Torqeedo in Crystal Lake, IL. “Are you going 40 mph all the time? Do you need to?”
Muskoka cottager Graeme Ferguson has immersed himself in research about electric propulsion technology since falling in love with his 36-foot 100-plus-year-old restored launch, Heather Belle. About 20 years ago, he replaced her Chrysler Crown six-cylinder engine with an Elco electric inboard motor, the equivalent of an 8 hp. Heather Belle will run at her displacement hull speed (roughly the fastest a displacement boat can go) of about 12 or 13 km/h, but he says, “I prefer to cruise slowly for a day on the lake.”
When Pierre Malo of Victoria, B.C., converted his 16-foot Lund to electric power, it wasn’t so much because he embraced the “slow boating” lifestyle, though he likes that too. His eye was on the bass and trout in freshwater lakes on Vancouver Island. Problem was, some of the smaller lakes have a 10 hp speed limit, and some prohibit any internal combustion engines at all. So he took delivery of the Lund without its usual 50 hp gas outboard. Pierre had already used a Torqeedo Ultralight 1 hp on his kayak, and he went back to the German company for a Cruise 4.0 with remote steering, which is comparable to an 8 hp gas outboard.
If this all sounds excruciatingly slow, be assured that you can go fast with electric. Both Elco and Torqeedo have developed high-power motors for planing boats—Elco’s EP 30 and 50, and Torqeedo’s Deep Blue series 25, 50, and 100. “Honestly, it’s expensive because of the setup it requires,” says Reinhart about Torqeedo’s planing option. The high-end Deep Blue 50 (equivalent to 80 hp) uses BMW i3 electric car batteries; a complete system with battery and motor can run $50,000 to $60,000 U.S., she says. Elco and Torqeedo’s electric non-planing motors retail for $1,700 to $9,000 U.S., plus batteries.
The batteries: How far do you want to go?
“Batteries are the gas tank, so depending on your needs and objectives, you select the size or capacity of your batteries accordingly,” says Elco’s Dean Heinemann. Your run time will be determined by the battery capacity and the average amp draw you use while cruising. (Amp hours are an indication of capacity, or the amount of current a battery can supply for a given period of time.) “But it all comes down to throttle management, and it varies by water current and conditions as well,” Heinemann explains. If you decrease your throttle, your run time and range will increase exponentially. If you’re in a strong current or windy conditions, you will need more power to maintain control of the boat during docking or other manoeuvres, and you won’t go as far. To add more range, add more capacity to your battery bank, or reduce speed.
Boaters have two battery options: lead acid and lithium ion. Lead-acid batteries are less expensive up front than lithium. (Count on at least $250 U.S. for a quality 12-volt, deep-cycle lead acid battery.) However, as they get toward the bottom of their charge, they don’t perform as well as lithium batteries, which means you’ll have less range. And they don’t recharge as quickly. They are also heavier than lithium, which can translate to hundreds of pounds difference in weight in the boat, and they take up more space. Lithium batteries can cost three to four times as much up front (Torqeedo’s Power 48 5000 is $5,200 U.S.), but comparing lithium and lead-acid batteries is like comparing apples to oranges. Lithium batteries perform more efficiently as the charge drops, can accept a greater depth of discharge, and can go through more recharging cycles than lead-acid batteries. That means you won’t need to replace lithium batteries as frequently and, over time, the price difference will narrow.
That was Pierre Malo’s conclusion. He installed a single Power 48-5000 lithium battery at the back of the boat where the fuel tank would normally sit. He paid close to $14,000 for the whole system and can troll for four hours (at a civilized 1.5 to 2.5 km/h) and still have 92 per cent of power left. After driving at maximum speed (11 km/h) going point to point all day for bass fishing, Pierre says his batteries will drop to 37 per cent. A networking cable connects the motor, the throttle, and the battery so that all the components talk to each other; the throttle display tells him how much charge he has left and, as he slows down or speeds up, how much farther he can go at a given speed. When he gets back to the dock, he just plugs the charger into any 110-volt outlet.
The chargers: What battery system did you choose?
Chargers are sold separately because they depend on which and how many batteries you use. Not surprisingly, lithium and lead-acid batteries need different chargers. Prices start at about $560 for lithium chargers and $200 for lead acid. Heinemann recommends investing in a high-quality charger with a balancing feature that makes sure your batteries are all charged to the same level. Also, people should charge their batteries right after use, he says, to help extend the life of the battery no matter how much you use it. If you’re new to it, working out the logistics of battery systems can make your head spin, so get advice from whoever is supplying your motor.
Imagine, though, if you could stretch the limits of range without having to go back to shore to plug in. Some larger boats use an onboard gas or diesel generator to recharge. Others have a backup engine for charging and for higher power needs. For brothers Tom and Mike Keevil, on Lake Vernon, near Huntsville, Ont., solar power was the answer. “Tom convinced our parents that they should be running a solar boat back and forth to the cottage,” Mike says. They built a canopy for their mother’s 18-foot pontoon boat, which doubled as a sunshade and a platform for the panels. They chose a Torqeedo motor equivalent to a 9.9, and Mike got four used 300-watt solar panels plus batteries.
Since then, the brothers have experimented with other boats. Last spring, Mike salvaged a 16-foot Springbok bowrider “on its way to the scrapyard,” erected a platform for two 300-watt solar panels, and installed an Elco 9.9, 48-volt outboard, plus eight 6-volt golf cart batteries. Figuring out where to place the batteries to keep the boat balanced is one of the tricks of electric conversion. Mike set them in the back to replace the weight of the 70 hp Mercury gas outboard he had removed, but many owners will spread the weight out under the seats or, for inboards, in the centre of the boat in the old engine compartment.
“Even if it’s a half-overcast day, I can fish forever for free,” says Mike. “I bring in about as much power as I draw.” His normal trolling speed is around 4 km/h, and he has enough power to fight wind or manoeuvre at the dock. On a dark day at top speed (about 10 km/h), he’ll deplete his batteries in 20 minutes, but his goal is to maintain a slower speed to avoid plugging in at their off-grid cottage, and let the panels do their thing. Last summer on a fishing trip in Temagami, Ont., he put about 70 km on the boat without depleting the battery, thanks to the solar panels and a stretch of bright weather.
Meanwhile, builders of boats across North America are moving towards electric motors. In Kelowna, for example, Templar Marine Group has developed five models on the same 26-foot hull for recreational and commercial use. “We think we’ve hit all the buttons for something that someone can buy today, and plug in [to a standard 110-volt outlet] today, and that uses as much power as a hair dryer,” says Mark Fry, Templar’s CEO. Templar boats are built by Campion Marine and use Exro Technologies propulsion, with a top speed of about 7 knots and a price tag of $140,000 Cdn. Vision Marine Technologies (formerly the Canadian Electric Boat Company) offers five models of electric boats, including the Bruce 22, shown above, which features mahogany woodwork and a maximum speed of 66 km/h.
Electric conversions are fun stuff for cottagers who love messing about in boats—or technology. But the concept doesn’t have to be complicated. The bottom line is that if you want more power, you’ll need a bigger motor. If you want greater range, you’ll need more battery capacity. The future will undoubtedly bring faster, more powerful, and more affordable electric boats. “We have seen the weight of lithium batteries come down as much as 50 per cent and pricing come down as much as 30 per cent over the last 18 months,” Heinemann says.
In 2019, for example, Torqeedo’s 24-volt 3500 battery had 30 per cent more power, though it was the same size and just two pounds heavier than its predecessor, says Mary Jo Reinhart.
The 12 lead-acid batteries in Graeme Ferguson’s century-old Heather Belle weigh one ton, not exactly a lightweight solution for going fast. But that’s the beauty of electric propulsion’s evolution. These days, there’s something for everyone, whether you like to go fast or troll around the lake all day. And though Elco has been around even longer than Graeme’s elegant launch, you might say that companies like it and Torqeedo are just getting started.
This article was originally published in the Aug/Sept 2021 issue of Cottage Life magazine.
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