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Electric boat repower calculator
Electric launch
Repower sizing guide

Small electric launch / day boat

Light displacement under 1.5 t, short days, simple 48 V system.

See the full spec for this boatOpens on the results — every value editable
Fits boats like
Cornish Crabber 17Duffy 18 electric launch

Not an exact match? The wizard adjusts to your real numbers — these are reference hulls for the typical sizing.

2 kW
Motor power
6 kWh
Battery pack
69 A @ 48 V
DC design current
10 nm (2 h at 5 kn)
Range on that pack

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 replaces — vs a 4 hp diesel
At 50 h motored per season (typical cruiser). Slider on the full summary lets you adjust.
Diesel displaced
23 L
per season
CO₂ avoided
61 kg
per season

What this segment looks like

Why a electric launch is a sensible repower target

Light launches and day boats under 25 ft don't need much power. For 1.2 tonnes at 5 kn the configurator estimates about 1.5 kW and suggests the 2 kW option, the next size up.

  • 48 V is plenty — the design current is about 70 A at the full 2 kW rating.
  • A 2 kW charger on a standard outlet takes about 3 hours from 20% to full on the 6.4 kWh pack.
  • Outboard conversions (e.g. ePropulsion, Torqeedo Cruise) are the fastest path.
  • Check displacement carefully — many 'small' launches are heavier than they look.
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Frequently asked questions

Electric launch — common questions

Quick answers to what most owners ask before starting a repower.

How many kW for a small electric launch?+
For a 1.2-tonne launch at 5 kn the configurator estimates about 1.5 kW, so a 2 kW motor — the next size up, with a little reserve for current and wind.
How long can I cruise on a smaller pack?+
Work it backwards: a 6 kWh pack at 80% usable depth of discharge, keeping a 15% reserve and 90% drivetrain efficiency, delivers about 3.8 kWh to the shaft — about 2.5 hours at the 1.5 kW needed for 5 kn, or about 12 nm. The configurator's 6.4 kWh is sized for 2 hours at the motor's full 2 kW rating.
Outboard or inboard for an electric launch?+
Outboard conversions (Torqeedo Cruise, ePropulsion Spirit/Navy) are the fastest path — you swap the gas outboard 1-for-1. Inboard makes sense if the boat already has a shaft or saildrive setup you want to reuse.
Can I charge from a regular 16 A AC outlet?+
Yes. A 2 kW charger draws under 10 A at 230 V, so a standard outlet handles it. It takes about 3.1 hours to take the 6.4 kWh pack from 20% to full; a smaller pack charges proportionally faster.
What does a small electric launch cost?+
All-in budgets typically run €3k–8k for outboard conversions and €6k–12k for inboard, depending on battery capacity and whether the install is DIY.
Other segments

Different boat?

30 ft sailboat35 ft sailboat40 ft sailboat40 ft catamaranTrawler yacht

Size your electric launch now

Opens on the results for this segment — every value editable. Free to run; PDF from €29.

Open the configurator