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Sleipner · tunnel thruster · bow or stern
Sleipner E170/250TC: specs, price and the boats it fits
It gives 375 lb (170 kgf) of push. Sleipner sells it for boats of 50 to 70 ft. It runs on 24 V or 48 V.
- Haul-out to install
- DIY 2 of 5: wiring prep only
- 2-year warranty
Quick stats
- Thrust 375 lb 170 kgf, Sleipner's rating
- Boat length 50 to 70 ft Sleipner's own range
- Price per lb of thrust $22.20 Unit only. $43 to $72 installed
- Voltage 24 V or 48 V As sold
- Battery at 24 V 751 CCA Two batteries, near the thruster
- Run limit Not published Ask the maker before long use
- To install it Haul-out The boat comes out of the water
- Anodes $33.75 A change, at Defender
About the Sleipner E170/250TC
The E170 pairs the eVision motor with counter-rotating twin propellers in a 250 mm tube, for boats of about 50 to 70 ft. It gives 375 lb of push on 24 V or 48 V, with the joystick setting how much.
Defender lists it at $8,325, against $6,264 for the on/off SE170. Check the listing against Sleipner’s own page before you buy: Defender’s prints the smaller E150’s thrust and power. The tube, a joystick panel, a main switch and a fuse add about $643 to $1,646; the batteries, cable and charging about $980 to $1,521. See every part.
Read more
Sleipner points owners of the discontinued SEP170 and SE170-IP here. It pairs the eVision motor with its five-blade Q-PROP propeller, which it says cuts noise by 20 to 40 percent in a typical boat. Full thrust can run continuously, limited by the batteries. Warranty: two years for leisure use, and it transfers.
Installing it yourself? The installer section has every spec, and the Sleipner (Side-Power) review sets this model against the rest of the Sleipner range.
Sleipner sold its thrusters under the Side-Power name until 2021, and many dealers and owners still call them that. It is the same company and the same thrusters.
Where this summary comes from (6 sources, read 12 October 2026)
- Sleipner product page
- Sleipner product page
- Defender, Sleipner E170/250TC eVision listing (prints the E150’s 150 kg and 8.1 kW)
- Sleipner E120 to E170 eVision installation manual, document 6825 rev 21
- Sleipner eVision (6-phase PMSM motor, up to 50 percent lighter, integrated inverter for variable speed, existing Sleipner models upgraded directly or with an adapter plate, the Q-PROP propeller)
- Sleipner warranty statement, effective 1 April 2022
Will the Sleipner E170/250TC steer your boat?
77 FT TRAWLER · BOW · 15 KT WIND
Every knot figure here is wind speed, not boat speed or current.
On a 77 ft trawler the Sleipner E170/250TC (375 lb) steers her in a 15 knot breeze. Her bow needs about 398 lb from a tunnel to steer her in a 15 knot breeze. Its 375 lb lands within 15 percent of that figure, which this site counts as enough.
The finder lists it for her.
The Sleipner E170/250TC on a trawler, by length
- 25 ft45 kt
- 30 ft38 kt
- 35 ft32 kt
- 40 ft28 kt
- 45 ft25 kt
- 50 ft22 kt
- 55 ft20 kt
- 60 ft19 kt
- 65 ft17 kt
- 70 ft16 kt
- 75 ft15 kt
- 80 ft14 kt
Outlined: the finder does not list it at that length (under 13 kt, far more than she needs, or outside Sleipner’s own length range).
- Under 10 kt
- 10 to 15 kt
- 15 to 20 kt: the sweet spot
- Over 20 kt: more than she needs
Prices are the low end of the installed total, from our estimate. For your own boat, drive and installer, the finder prices each unit.
Is it right for your boat?
Every kind of boat it fits, by length
| Boat | Full thrust at 15 knots | Still a fit, in lighter wind |
|---|---|---|
| Pontoon & tritoon | Not listed. A pontoon has no hull body between the logs to bore a tunnel through, and nobody sells one for these boats. | |
| Sailboat | 54 to 77 ft | None |
| Houseboat | 45 to 58 ft | 59 to 66 ftfull thrust to about 13 knots at 66 ft |
| Catamaran | 61 to 77 ft | None |
| Trawler | 53 to 77 ft | None |
| Motor yacht | 53 to 77 ft | None |
| Bass & flats | Not listed. Nobody sells a tunnel kit for these hulls, and a bass boat’s shallow planing bow has almost no depth to hold one. | |
| Wake & ski boats | Not listed. Nobody sells a tunnel kit for these hulls. | |
| Express cruiser | No length. More thrust than the boat needs. | |
| Center console | No length. More thrust than the boat needs. | |
The Sleipner E170/250TC against each kind of boat, in a 15 knot wind. Our sizing, from the finder’s own rules.
The first column is where one unit gives all the thrust the boat needs in 15 knots. The second is where the finder still lists it: the unit steers her in a 13 or 14 knot wind, within 15 percent of the 15 knot breeze this site sizes for. On a boat shorter than the first column’s shortest length, the unit is more than the boat needs.
How we size it
Our figure is the longest boat one unit can steer in a 15 knot wind. It is a range because each kind of boat catches the wind differently. Here a houseboat gets full thrust to 58 ft, and a sailboat to 77 ft. The maker gives one range for every boat.
The table tries the Sleipner E170/250TC on each kind of boat, at every length that kind of boat is built in. The wind is 15 knots and the rules are the finder’s own. A length counts as a fit when the unit gives the thrust that boat needs at the bow and the maker lists it for that length.
A boat up to 10 percent past the maker’s range still counts here, as it does in the finder. So the table runs down to 45 ft and up to 77 ft, just past Sleipner’s own range (50 to 70 ft).
It is sized for five kinds of boat here. For your own boat, the finder gives an answer that also counts your drive and who does the installing. The compare page sets this unit beside others.
What it costs installed
A yard job, everything in. Our estimate.
| Boat | Total installed |
|---|---|
| 45 ft | $15,868 to $25,182$42 to $67 a lb of thrust |
| 60 ft | $16,228 to $26,992$43 to $72 a lb of thrust |
| 77 ft | $16,508 to $27,812$44 to $74 a lb of thrust |
From the shortest to the longest boat it is sized for.
What is in each total
These totals are our estimate of a yard job: the unit’s price, plus a yard’s hours at $160 to $180 an hour, plus the batteries, cable and charger, plus the other parts the box does not hold. A Lifting the boat out of the water on a travel lift or a trailer so work can be done below the waterline. It is billed separately from the job itself. adds $800 to $3,720 at these lengths, with 5 to 7 days out of the water, worked from eight yards’ own rate cards. The hours come from what owners and yards report. The cost page builds the same figures line by line.
| Boat length | The unit | Yard labor | Haul-out | Batteries, cable, charger | Other parts |
|---|---|---|---|---|---|
| 45 ft | $8,325 | $5,120 to $11,52032 to 64 hours | $800 to $2,170 | $980 to $1,521 | $643 to $1,646 |
| 60 ft | $8,325 | $5,120 to $12,60032 to 70 hours | $1,160 to $2,900 | $980 to $1,521 | $643 to $1,646 |
| 77 ft | $8,325 | $5,120 to $12,60032 to 70 hours | $1,440 to $3,720 | $980 to $1,521 | $643 to $1,646 |
For every length in the table above.
How the batteries, cable and charger add up. We price a battery bank close to the thruster, as the makers recommend, with 10 to 20 ft of cable out and back: red for the positive, black for the negative, cut to length. The low end is the cheapest battery that meets the figure and the shorter run; the high end is a sealed (AGM) battery and the longer run. The charger is a NOCO GEN5X2 two-bank shore charger.
Batteries and lugs are priced at Fisheries Supply and the cable and charger at Defender, read 26 October 2026.
- At 24 V: two 12 V batteries in series, at least 751 CCA each (Sleipner’s minimum), $720 for both; Sleipner’s cable table gives 2/0 AWG: $114 to $201 for the red and black cable and the lugs; a GEN5X2 charger, $146.
- At 48 V: four 12 V batteries in series, at least 380 CCA each (Sleipner’s minimum), $1,027 for all four; Sleipner’s cable table gives 2/0 AWG: $114 to $201 for the red and black cable and the lugs; two GEN5X2 chargers, $293.
The sizing and the costs on this page are estimates, for guidance only and without warranty. They are no quote, and nobody has inspected your boat. Check them against the maker’s manual and your yard before you rely on them. Terms of use.
DIY breakdown
DIY levels
- Level 5: Owner install. No yard, no electrician.
- Level 4: You install it, electrician connects. You mount and wire it; a marine electrician makes the final connections.
- Level 3: Split with the yard. The yard does the below-waterline part; you do the wiring.
- Level 2: Wiring prep only. The yard installs the unit and does the hull work; you do the wiring prep.
- Level 1: Yard job. A qualified professional does all of it.
You Yard Electrician. The bar is labor hours; a haul-out is a note.
How we rate DIYYou: 4 to 16 hours Yard: 32 to 70 hours Electrician: 2 to 4 hours Plus a haul-out.
Your part needs:Heavy battery cableCrimping big lugs
Every step, and who does it
- Cut, bond and fair the tunnel; fit the gear leg, motor and propeller Yard 32 to 70 hours The low end is two crew over two days, the job as owners describe it on the forums. The high end rises with boat length between two real billed figures: 32 hours at 35 ft, and the largest invoice we hold, 70 hours at 47 ft.
- Mount the battery box, switch and fuse holder; run and secure the cables You 4 to 16 hours Our estimate. No maker times this step, and a first-time owner is slower than a yard, so the range is wide.
- Final connections at the battery and the motor, load test Electrician 2 to 4 hours Our estimate. Nobody publishes a time for the final connections and test on their own.
A qualified marine electrician should make the final connections and test them before first use. Hours are labor only.
Related videos
Two from Sleipner’s own channel and one from other channels. Each one is labeled. They play from YouTube only when you tap. Take any claim in a video back to the figures on this page, which are the ones we checked.
Know before you buy
What sets this model apart, what it costs to keep, and what to weigh.
Price per pound of thrust
$22.20 a lb The unit’s price over its published thrust. The bars are Sleipner’s next sizes and the nearest other makers.Controls
A brushless eVision motor on S-Link control. The panel, fuse and main switch are bought.
Anodes
$33.75 a change- Anode (250 and 300 mm gear leg) (SM201180A): $33.75 at Defender, $42.19 at Fisheries Supply.
They sit below the waterline, so a change means a haul-out or a diver.
Service and warranty
Sleipner gives 2 years for leisure use and 1 for commercial use. It transfers to the next owner, and it starts no later than 18 months after the boat's first launch.
See Sleipner’s warranty Sleipner's warranty statement, effective 1 April 2022.Special mentions
Battery: at 24 V it wants two batteries of 751 CCA or more, Sleipner's figure. The cheapest that meets it is the Optima BlueTop SC27DM Group 27 AGM, $359.99. Check your own bank.
Charger: a NOCO GEN5X2 two-bank shore charger, $146.41. It is the one our estimate prices.
Sleipner sells it for either end, so it can go at the bow or the stern.
Dealer prices at Fisheries Supply, read 26 October 2026.What to weigh
The boat comes out of the water to install it: it needs a tunnel bore below the waterline.
Parts for the Sleipner E170/250TC
See the Sleipner E170/250TC manualThe US dealer number comes first, then Sleipner’s own. Prices are each dealer’s on the day shown, before shipping and tax. Check the plate on your motor before you order: some parts change with the tunnel size, the voltage or the year.
For the install what the box leaves you to buy
The manual button above opens it on the maker's product page. It has the hull, wiring and fuse figures for this model.
From Sleipner’s E120 to E170 eVision installation guide, document 6825 rev 21, 2025, read 25 October 2026.
- In the box
- The guide prints no box list. It has you install the unit with the gasket and the bolts provided.
- Bought separately
- The ANL fuse and a main switch ("must include"), an S-Link control panel with its own guide, the S-Link cables, the tunnel and the battery cable. Imtra, Sleipner's US distributor, lists the same items to buy with a new thruster.
- Charging
- The word "charging" is not in any of the Sleipner guides we read. The battery is sized by cold cranking amps, and a battery near the thruster is suggested. How it gets charged is left to you and your installer.
In Sleipner’s words, from its SE80 to SE150 installation guide, document 2687 rev 30, page 19: “For installations on large vessels with bow and stern thrusters or catamarans a dedicated battery for each thruster should be considered.”
The “other parts” line in the estimate above covers these parts as a range, $643 to $1,646 at Fisheries Supply’s prices on 30 September 2026 and 26 October 2026, because the exact items depend on your boat. The batteries, cable and charger have a line of their own. The cost page has what every maker says about each part.
Outside the hull replacement parts in the water
Anode (250 and 300 mm gear leg)
The metal that wears away in the water so the drive does not. Sleipner calls it “Anode kit, aluminium aloy (Al-Zn-In)”.
Propeller, left hand (250 mm)
The propeller on the drive. Sleipner calls it “Propeller, Q-Prop™ Ø250mm LH”.
Propeller, right hand (250 mm)
The propeller on the drive. Sleipner calls it “Propeller, Q-Prop™ Ø250mm RH”.
Gear leg gasket
The leg under the motor that turns the propeller. Sleipner calls it “Gasket for gearleg/tunnel SE130/170/210”.
Sleipner lists it on the gear leg parts page for these models.
Gear leg, with propellers
The leg under the motor that turns the propeller. Sleipner calls it “Gearleg SE170/210”.
Inside the boat replacement parts on board
Main fuse
The main fuse at the battery, in the rating the maker gives. Sleipner calls it “Recommended fuse A”. This one is for the 24 V version.
The rating on Sleipner's product page for this model.
Replacement motor
The electric motor that turns the propeller. Sleipner calls it “E170 Motor 24V”. This one is for the 24 V version.
Replacement motor
The electric motor that turns the propeller. Sleipner calls it “E170 Motor 48V”. This one is for the 48 V version.
No part matches. Try the number without spaces, or the part’s name.
Spare part numbers come from Sleipner’s parts pages and manuals. A dealer may sell a part we have not priced. Search for the number.
Other sizes and close alternatives
- Size down Sleipner E150/215T 331 lb · $7,875
- Size up Sleipner E210/250TC 463 lb · $10,125
- Other maker VETUS Bow Pro Boosted 180 397 lb · $7,749
- Other maker Max Power CT165 408 lb · $3,684
- Other maker Lewmar 250TT GEN 2 308 lb · $4,949
The other makers listed are the nearest match each makes, of the same style and for the same end, within a quarter of its thrust. The compare page lists every model, and the thruster index lists every model with a page here.
For the yard and the installer
Every published figure, with its source.
Full spec sheet
| Thrust and motor | |
|---|---|
| Thrust | 375 lb (170 kgf) As printed: 170kg / 375lbs (Sleipner E170 eVision 24 V product page, read 2 Oct 2026; Defender prints 150 kg / 330 lbs, the E150 figure) |
| Motor | 8.1 kW |
| Voltage | 24 V or 48 V |
| Run limit | Not published |
| Installation | |
| Type | Tunnel, fixed mount |
| End of the boat | Bow or stern |
| Tunnel diameter | 250 mm |
| What it does to the hull | Tunnel bore below the waterline |
| Haul-out to install it | Yes |
| Maker’s boat length | 50 to 70 ft |
| Price and ordering | |
| Price | $8,325 equipment only, a dealer's price, defender.com, 26 October 2026 |
| Part number | 99968824 V/48 V |
| Documents | |
| Manual | Installation manualon the maker's product page |
| The site’s review | Sleipner (Side-Power) review |
Every published figure the site holds for the Sleipner E170/250TC, with where each came from.
Draw, cable, fuse and battery at each voltage
These are the maker’s own figures, at each voltage it is sold at. The cable is the size for the shortest run in the maker’s table. A longer run may need heavier cable, and the wiring calculator works that out for your own boat.
| Voltage | Draw | Maker’s cable | Fuse | Battery | Run limit |
|---|---|---|---|---|---|
| 24 V | 395 Anominal draw | 2/0 AWG for up to 22 ft of cable counted out and back. Longer runs take heavier cableinstallation guide | ANL 355installation guide | 395 CCA DIN minimumSleipner installation guide, E120 to E170 eVision, document 6825 rev 21 (2025) | Not published |
| 48 V | 200 Anominal draw | 2/0 AWG for up to 22 ft of cable counted out and back. Longer runs take heavier cableinstallation guide | ANL 150installation guide | 200 CCA DIN minimumSleipner installation guide, E120 to E170 eVision, document 6825 rev 21 (2025) | Not published |
The Sleipner E170/250TC’s draw, cable, fuse, battery and run limit, as the maker publishes them.
- At 24 V: size the cable for your run, or check the battery you have.
- At 48 V: size the cable for your run, or check the battery you have.
The tunnel: length and depth rules
Tunnel length. Avoid a tunnel longer than four times its diameter. Friction inside a long tube slows the water and cuts thrust. Too short, and the flow reaches the propeller before it has straightened, which the manual says causes cavitation and noise. The propeller must sit entirely inside the tube. Sleipner’s installation manual.
Depth below the waterline. As deep as possible under the waterline, and as far forward as possible. The depth for a given model is in that model’s own measurements. Deeper prevents air being sucked in from the surface and raises the water pressure at the propeller. SE20 to SE40 installation guide, 5611 rev 25 (2025).
Our notes from the manual and listings
In the box: A brushless eVision motor on S-Link control. The panel, fuse and main switch are bought.
Our note
The brushless eVision motor comes from the series launched in 2022. The page rates it continuous at 22 C, limited only by the battery. The motor holds one thrust figure across the voltage range. The brushed series print a lower figure at the voltage a battery sags to. Twin counter-rotating props in a 250 mm tunnel, sold at 24 or 48 V, for boats of 50 to 70 ft.
The thrust here is Sleipner's own 170 kg. Defender's page prints 150 kg and 8.1 kW, the smaller E150's figures, so check the maker's page before buying on the name. Sleipner's FAQ wants the tunnel at least three quarters of its diameter below the surface, never less than half.
Where each point above comes from
- Sleipner sells it for either end, so it can go at the bow or the stern.The maker's listing
- It is sold at 24 V and at 48 V.The maker's and dealers' listings
- The boat comes out of the water to install it: it needs a tunnel bore below the waterline.The mounting: a bore through the hull, or a housing recessed into it
Not sure this is the one? The thruster finder asks about your boat and prices every unit that fits.