Making waves — Electric power on the water

Most electric boats can be charged at home. Using a smart, wall-mounted charger is the safest and fastest option — fully charging a 40kWh battery in up to 12 hours. 

While away from home, public chargers can be used while your boat is on the trailer. A 50kW DC fast charger can charge a 40kWh battery to 80% in about 40 minutes. 

Dock-side charging infrastructure isn’t widely available yet, but in the future, this will become more common and practical.

Yes — electric boats are designed with multiple safety features to ensure they’re safe to use on the water. While it’s natural to wonder about mixing electricity and water, the technology is well-developed and proven. 

High-voltage systems have been used safely in marine vessels for years. The battery is housed in a sealed enclosure that protects it from water and physical damage. As Michael puts it, “It’s ultimately very similar to driving down the road with your electric car with a battery underneath — it’s a sealed unit.” 

Of course, no system is completely risk-free, but electric boats are built with robust safeguards to manage those risks effectively.

Electric boats can match — and in some cases exceed — the performance of petrol or diesel-powered boats.  

In fact, many users are surprised by the power and responsiveness. Like an electric car, electric boats deliver instant torque, giving them excellent acceleration and that initial up-and-go that’s ideal for getting up on the plane quickly. 

There’s still room to optimise performance and efficiency further through things like propeller choice or adding a passive hydrofoil to reduce drag, but these features come with added cost. Mike and Jeff have found that even without pushing the motor to its full torque, they are getting more than enough power for their needs.

Whether an electric boat’s range will meet your needs depends on the battery size and how you use your boat. A 40kWh battery pack typically delivers about 40 minutes to 1 hour of run time at cruising speed, depending on the boat the kit is fitted to. But real-world usage often involves long periods at idle or low speed, which use little or no power — unlike petrol boats that continue to burn fuel even when not moving. 

Michael says, “From our testing, only about 25% of the time is spent at full power. The rest of the time, the boat is essentially just sitting there — not using energy.” 

Larger battery packs (60kWh or even 80kWh) can extend the range significantly. However they come with trade-offs in terms of space, weight and added cost. 

The technology is improving fast, with newer batteries offering better kWh per kg. But ultimately, whether an electric boat meets your needs comes down to your use case. “Quite often people think they use their boat more than they actually do. Understanding your true usage is key,” says Michael. 

Electric conversions won’t suit every type of boating — like long-range offshore trips — but for your typical family fun day out, they’re more than capable.

Not significantly. In the conversions that E-Stroke has done, the total on-water weight came to 996 kgs — only about 15 to 20 kilograms heavier than the original petrol-powered setup. That’s a very minor difference in boating terms. 

In fact, the weight distribution improved. The electric motor is lighter than the internal combustion engine it replaced, and the batteries were positioned further forward — closer to where the fuel tank used to be. This shift in balance has actually enhanced the boat’s handling and performance on the water. 

So while there's a slight increase in weight overall, it’s minimal and can even result in a better ride thanks to smarter weight placement.

Electric boats require significantly less maintenance than petrol-powered ones. You don’t have spark plugs, fuel filters, or oil changes like you would with a two- or four-stroke engine.  

There are still some components that need attention — such as the gearbox oil and electric water pumps — but the number of moving parts is drastically reduced. Fewer parts means fewer things to wear out or go wrong, which translates to less time and money spent on upkeep. 

Overall, the simplicity of electric systems makes them much easier and cheaper to maintain over the long term.

If you're passionate about electric transport and thinking of getting into this space, Jeff says — just do it. “We’re driving an outcome that we are passionate about, that we believe is the future… and we’re getting a lot of joy out of doing it.” 

There’s real opportunity in marine electrification.  Maritime NZ estimates there are up to 440,000 small power boats (up to 6 m long) in New Zealand.* Many of these could be candidates for electrification. And that’s just one part of a much bigger picture — there’s also potential across sectors like farming, viticulture, and bespoke machinery, where electric conversion could make a big impact. 

This is a growing field with room for more players. “The more electric boats out there, the better,” says Michael who offers another practical tip: “Get the right partners around you.” While doing as much as possible in-house can be rewarding, Jeff and Michael have found that leaning on experts — like VCU or battery specialists — has made a huge difference to their success.

*Maritime NZ Recreational Boating Monitor 2023-2024(external link)