Leopard 46 Electric Drive

Three years ago, when we launched this Forever Green Special Issue, we were generally satisfied with the theoretical data provided by equipment manufacturers. Then we were able to test the first electric catamarans for a few hours, which was a much better thing. Last year, we collected the first testimonials from owners who had completed ocean passages. Could we find out more? Yes, by spending 24 hours on board to learn everything there is to know about electric propulsion and better understand how it works in typically “current” use. We contacted the Leopard Catamarans team: their base in Saint-Raphaël is home to a Leopard 46 Electric Drive. For the sake of consistency, we also had the use of a Highfield tender powered by an electric outboard.

Reassuring Range

When we cast off in the late afternoon, the batteries were at 100% as we’d been hooked up to the shorepower until 4pm. Useful information: when connected to shorepower, the battery bank recharges in four hours. As our plan was to enjoy complete freedom, the option of plugging back in during our unpretentious mini-cruise was obviously out of the question.

The Leopard 46 Electric Drive we had was equipped with a system designed by Joool – it’s exactly the same as the one fitted by Fountaine Pajot. Each hull is equipped with a 25-kW motor/pod and a 27-kWh battery. The builder also offers 21, 32, and 38 kWh options. The catamaran is equipped with four 400 Wp solar panels, a 4 x 210 Ah AGM service battery bank in 12 V (in our opinion, this bank would benefit from being upgraded to lithium) and a powerful 24-kW generator. On paper, the figures speak for themselves: if you want to sail at full speed (8.5 knots), the generator will start up in less than an hour and maintain a maximum speed of 7.5 knots. By barely touching the throttle, you can “motor” for 550 miles at 7 knots, and 920 miles at 6 knots. These figures are comparable to those of a “fully internal combustion” unit, if that’s any consolation... but our goal, in this Forever Green Special Edition, is rather not to touch the 180 US gallons (690 liters) of diesel we’re carrying...

A word about the powerful generator: it is still very useful on board, as one hour of runtime recharges the battery bank to 45%, or provides two hours of engine power at 6 knots, or four hours at 4.5 knots. But here’s the thing: the generator, soundproofed as it is, is still noisy and even makes maneuvering in port kind of tricky when it’s running

In Slow-life Mode...

Once the plug is pulled, we obviously switched to another mode, the autonomy mode that interests us here. Leaving the slip was smooth and quiet. There’s no need to push the levers hard down to ensure rapid power: you can feel that the electric motors have high torque. The so-called throttle levers seemed pretty small and sensitive to me, but you do get used to them.

We were in front of the ...