Changing our mindset on EV sailing – how to reduce ‘range anxiety’

Changing our mindset on EV sailing – how to reduce ‘range anxiety’

When a sailboat uses electric propulsion, battery recharging needs to be factored into the journey. How often is recharging needed, is probably the most common question asked by sailors who currently have a diesel engine, and are considering converting to electric propulsion.

The answer is, it depends on how you use the motor. Many sailing trips involve some friends and family on a day sail in and around the harbor, or not too far from it. In this case, no real planning is needed. Before leaving, unplug the AC power from the dock, untie the boat, and motor the vessel out of the slip and into the harbor where you can set the sails and enjoy a day sailing. Use the motor as needed to position the boat, including things like anchoring, lowering and raising the sails, and motoring around if the wind is low, or just back into the slip at the end of the day.

For multi-day trips, such as going from one marina to another, planning for battery recharging is needed. For example, when I’m going between Long Beach and Newport Beach, before departing I’ll have the battery fully charged. During the voyage, if the wind is light or non-existent, I’ll use the motor to get the boat moving between 4 to 6 knots. I’ll set the speed, based on the amount of time I need to motor and how much battery charge I want to have available once I get near the destination. The night I arrive, I’ll check into a guest slip and recharge the battery back to 100%.

For longer trips such as multi-day sailing to Catalina Island, where guest slips with shore power are not available, I’ll recharge the battery using a propane powered generator. If the wind was strong during the trip, the need for motoring is minimal and the battery will remain mostly charged. However, if hours of motoring were needed and the battery becomes low, a propane powered 2000 watt generator works perfectly for recharging.

On my Hunter 33, the propulsion battery is charged from a 1200 W charger, so this generator is sized well for the job. This same generator also charges the house batteries, which is a totally separate electrical system on the boat, used for lighting, the water pump, electric windless, etc.

I like using a propane fuel generator, since it’s liquid free (no gasoline tank needed), and I already keep bottles of propane on board to fuel the boat’s stove. Most importantly, it burns clean, and no gasoline ever needs to be brought on board.

This is the generator I use for recharging when away from shore power:


It’s small and lightweight (55 Lbs), and can be stowed in an outside compartment, easily set up on deck and run for hours if needed. With this, recharging the battery while away from shore-power is no problem, and makes multi-day sailing trips using electric propulsion a breeze.

Having a wind turbine and/or solar array is great for maintaining house batteries, but it’s not really sufficient if much motoring is needed. It’s better to keep the small generator on board, for recharging when shore power isn’t available.

Walt White

Founder and lead systems engineer, working to bring new products to market that make a positive impact to the environment. Our products and services help boats make the switch to battery electric propulsion, harness renewable energy, and solve other challenges involving marine electric propulsion systems.

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