A complete electric outboard system including 18kW motor, controller, batteries, charger, cables, remote control and state-of-charge meter is being offered by Stealth Electric Outboards for less than US$10,000.
That’s another indicator that the electric boat and motor market is changing quickly and becoming more and more accessible to the average boat owner. Many people who are interested in going electric get discouraged by the price or frustrated by the unfamiliar terminology and the details of matching voltage and amps and battery chemistry with the motor.
After all, when they go to buy a fossil fuel motor, the salesperson doesn’t make them figure out what octane of fuel and viscosity of oil they’re going to use. Everyone agrees that and operating an electric motor is simple – this Stealth complete package – and others – are a way to make choosing an electric motor equally easy.
The idea behind the Stealth E18KW is to offer an all-in-one complete electric outboard system to power most smaller lightweight boats at planning speeds of 18-20MPH for at least an hour. For an idea of performance, see the video at the bottom of this article which shows a slightly smaller Stealth (14.5kW) powering a 17 foot jon boat.
Maximum flexibility in battery configuration
The Stealth E18kW is – not surprisingly – an 18kW motor that equates to a 23.4 HP gas motor in a straight kW to horsepower conversion of 1 to 1.3. One of the appealing aspects of the motor is that it can run on 48 volts or 96 volts, which provides a lot of flexibility and options for the purchaser.
There are two battery packs in the recommended standard offering, each a 48V module with 135Ah and 6.48kWh of capacity. When connected in series they make up a 96V system with 12 kiloWatt hours of electricity available. There is also the option (less expensive) of purchasing the package with only one 48V module and adding the second later.
Modules can be also added in parallel to increase the range. As a brief explainer, when batteries are added in series, the available power increases – in the example above, from 48 to 96V. When added in parallel, the storage capacity increases from 12 kWh to 24 kWh. So a 4 module package (2 in series, 2 in parallel) would provide 96V and 24kWh.
In all of these cases, the Stealth package uses a simple click and connect system, and each module has built in active balancing, meaning that charge is automatically redistributed between the individual cells when in use to help increase run time and battery life. The system also includes a monitor/state-of-charge meter for real time status.
At 70 lbs • 32 kg, each lithium ion 48V module weighs about the same as a lead acid marine deep cycle 12V battery but provides up to 6 times the capacity. The charger is a 3.3kW model that accepts both 110VAC and 220VAC input. The final part of the complete electric outboard package is a side mount throttle.
The controller and sensitive electrical components for the E18kW are all housed in a polyethylene case that is rated IP65.
Complete electric outboard package makes it easy
One of the reasons the E18kW can be offered at a sub $10,000 price is that it started life as a clone of a Yamaha gas burning outboard, using the same shaft, gearing, housing and other components. This keeps the production cost down and also means that any replacement parts for the lower unit, such as impellers and props, can be found at local Yamaha Marine parts departments and replaced quickly and affordably.
All in all, this is a product that makes switching to electric power simple to understand and affordable. Scott Masterson, the man behind Stealth, says “I have been asked for years to put together a powerful complete solution that includes a sizeable battery pack, charger, display and cabling for less than $10,000. Now I’ve done it!“
Perhaps part of the reason for the user friendly package is that Scott is like so many of his customers. We wrote about him back in February of 2019 and how he first started putting together electric motors because he and his wife had purchased an old pontoon boat with a gas burnin goutboard that (stop us if this sounds familiar) kept developing problems.
He went on to put an electric motor in the pontoon, then a more powerful one to replace a Mercruiser 3.0 litre engine in a 17.5 foot Bayliner, and then develop his first electric outboard, the Stealth 40 (now called the Stealth E36kW).
You can find out more and purchase either motor on the Stealth website, but as Scott says, “I think that for many people they will be happy to compromise a bit on the power and get greater range and a more affordable package.”