Westerly Konsort 29 electric repower: motor, battery and cable sizing
The Westerly Konsort 29 is a 8.8 m monohull with a 7.77 m waterline and 4,178 kg displacement. From those figures, the configurator's sizing model puts an electric conversion at 4 kW and 13 kWh on a 48 V system.
Boat data: sailboatdata.com — Konsort 29 (Westerly), checked 23 October 2026
Motor power
4 kW
4 kW needed at 5 kn
Battery pack
13 kWh
2 h at full rating, with reserve
DC design current
139 A @ 48 V
cabling burden: easy
Range on that pack
10 nm
at 5 kn
The boat
- Length
- 8.79 m
- Waterline length
- 7.77 m
- Beam
- 3.28 m
- Displacement
- 4,178 kg
- Hull
- Fin keel, transom-hung rudder
- Designer
- Laurent Giles
- Builder
- Westerly Marine Ltd. (UK)
- Built
- 1979–1991
- Number built
- 704
- Original engine
- Bukh DV20ME — 20 hp
Power needed by speed
| Speed | Shaft power |
|---|---|
| 3 kn | 1.1 kW |
| 4 kn | 2.2 kW |
| 5 kncruise target | 4 kW |
| 6 kn | 6.9 kW |
| 6.8 knhull speed | 10.5 kW |
The configurator's power-per-tonne heuristic, not a tank test — real boats vary by about ±25% with hull form, fouling, sea state and propeller. Near hull speed the power climbs steeply.
48 V or 96 V
48 V systemconfigurator's choice
139 A
design DC current · cabling burden easy · 35 mm² for a short run
96 V system
77 A
design DC current · cabling burden easy · 16 mm² for a short run
Motor lines that cover 4 kW at 48 V
From our motor comparison, matched by power and system voltage only — check drive type and fit with the maker.
What these numbers assume
- The published displacement. Your boat loaded for cruising is heavier — use your own figure in the configurator.
- Cruise target of 5 kn, which is 75% of the 6.8 kn hull speed.
- A shaft drive (assumed — the source doesn't say; a saildrive adds about 4%).
- A pack sized for 2 hours at the motor's full rating, 15% reserve and 80% usable depth of discharge.
- The Westerly Konsort 29 was built from 1979 to 1991; versions changed over that time, so check your own boat's figures.
Westerly Konsort 29
Common questions
How many kW does a Westerly Konsort 29 need for electric propulsion?+
About 4 kW to hold 5 knots — 75% of its 6.8-knot hull speed — so the configurator suggests a 4 kW motor. Power rises steeply above that: about 10.5 kW at hull speed. These are estimates from the boat's published waterline length and displacement; real boats vary by roughly ±25%.
What size battery does a Westerly Konsort 29 need?+
The configurator sizes about 13 kWh of LiFePO4 for 2 hours at the motor's full 4 kW rating, with a 15% reserve and 80% usable depth of discharge — about 10 nautical miles at 5 knots. Cruising below full power stretches that.
Should a Westerly Konsort 29 use 48 V or 96 V?+
At 4 kW the design DC current is about 139 A at 48 V (cabling burden: easy) and about 77 A at 96 V (easy). The configurator picks 48 V for this boat: it stays on 48 V unless the 48 V current reaches its "very heavy" level.
More on this size of boat
30-foot sailboat electric repower