40-foot sailboat electric repower
Bigger cruisers and offshore boats — where 96 V starts to make real sense.
Not an exact match? The wizard adjusts to your real numbers — these are reference hulls for the typical sizing.
Calculated by the configurator for the example boat below, sizing the pack for 2 hours at the motor's full rating with reserve. Open it to change any input.
What this segment looks like
Why a 40 ft sailboat is a sensible repower target
At 40 feet and 9–11 tonnes, the configurator estimates about 10 kW for a 10.5 t boat to hold 6 kn, so a 15 kW motor. At that power 96 V makes sense — at 48 V the design current would be about 520 A.
- 96 V roughly halves the DC current vs 48 V — about 290 A instead of about 520 A at 15 kW.
- Each hour at the full 15 kW rating adds about 24 kWh of pack; 48 kWh covers 2 hours with reserve.
- Shaft drive is still the most common 40 ft layout; saildrive options narrow above 25 kW.
- A 7 kW charger refills the 48 kWh pack from 20% in under 7 hours; 11 kW takes about 4.
Related sizing guides
Current, cable size and cabling burden at 48 V and 96 V for every motor size from 2 to 25 kW, and where the answer flips.
How to size DC cables for electric boat propulsion — voltage drop, cross-section, fusing, and why getting it wrong is expensive.
Everything a boat owner needs to know about lithium iron phosphate batteries — chemistry, sizing, safety, BMS, and installation best practices.
Frequently asked questions
40 ft sailboat — common questions
Quick answers to what most owners ask before starting a repower.
Why go 96 V on a 40-foot sailboat?+
How much battery do I need for offshore work?+
Is hydro regen worth it on a 40-footer?+
What charging power should I plan for?+
Shaft drive or saildrive on a 40 ft electric repower?+
Different boat?
Size your 40 ft sailboat now
Opens on the results for this segment — every value editable. Free to run; PDF from €29.