Sleipner/Side Power Thruster Failures in new units

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James E

Member
Joined
Feb 19, 2024
Messages
8
Vessel Make
Grand Soleil 46 LC
Hello, I'm the owner of a brand new 46 foot European built yacht which has factory fitted Sleipner/Side Power retractable bow and stern thrusters. The thrusters are wired to the house battery bank ( 570 AH capacity).

During commissioning the bow thruster started rapidly moving between port and starboard. It was then shut down and it was discovered that the coupling had sheared. Earlier that day the stern thruster had stopped delivering thrust. On further investigation it was discovered that the coupling had also sheared.

The local Sleipner agent initially blamed the problems on either “set up issues” or “low voltage”. Later its seems to have been accepted that the bow thruster issue was caused by a stuck solenoid/controller and the side to side movement is an attempt by the software to un-stick it (although one that resulted in sheared couplings). The new controller box and couplings took 6 weeks to arrive.

After installation both thrusters worked correctly, however 1 week later the stern thruster sheared the coupling again ( the stern thruster had been successfully operated in approximately 3 berthings since the new coupling was installed).

Annoyingly the plastic clip on joysticks on the dual proportional thruster controller have a habit of falling off if pressed low down and I have had to SuperGlue them on, since they were often falling off at critical times during berthing manoeuvres.

3 months since the initial problem, the marine electrician has identified that the stern thruster doesn’t seem to have any form of delay in it when it moves from one side to the other, whereas the bow thruster does have a delay. His theory is that it is an older unit where the delays were activated by relays, which seem to be missing from the unit. Apparently the new models have a delay built into the software, so the theory is that upgrading the software on the older model might help. I am yet to receive any confirmation from Sleipner on this theory and the documentation is unhelpful.

I have never activated the thrusters for more than a second or 2 at a time and the battery and engine temperature indicators on the controller have always showed close to full remaining capacity. On a couple of occasions the bow thruster stopped working with a “Communications error”, but then worked again after being turned off and on. I have also had occasional low voltage warnings from the B&G instruments that are connected to the house bank. There has been a high failure rate in instruments connected to the house bank ( depth sounder, auto-pilot controller, auto pilot rudder reference unit and windlass chain counter sensor) which might be related. The batteries are fine and have been tested by the marine electrician.

I’m not going to comment here on the level of engineering, quality control and support in this saga ( it should be obvious to anyone reading this), however it would be great to hear of any suggestions or experiences, given the glacial pace of support and in particular whether it should have been installed off the house bank and whether that is of adequate capacity.

Many thanks,
 
Without knowing the specs(current draw) and wiring details(length and wire gauge) it is not possible to know. But generally I think this type of very heavy inductive load should be on a dedicated battery bank. If you are seeing multiple other instrument failures that probably confirms the current setup is suspect.
 
New poster so I'm guessing he is not communicating with us a perfectly as he would like. I'm guessing he meant to say the thruster was connected to a 570 CCA battery. I may be wrong so we should clarify if the thrusters have their own bank or are connected to the house bank. Connected to the house bank would create long cable runs and would most likely be victim to voltage drop.

With out seeing the installation there is plenty of opportunity for the instillation to be the issue.
 
Sorry for not making it clear. Its connected to the house bank, which consists of 6 AGM batteries, with each one rated at 850CCA and 96 Amp Hour capacity.
 
Mine have separate battery back and are 21 volt. They use a lot of juice so you dont get much time. If you using the house bank and using the thrusters on the heavy side you may be draining the house bank causing you the other problems.
 
The first thing I would check is what is the voltage at the thruster when it is working, or under load? What is the length both to and from the battery bank to each thruster and what are the cable sizes? I do not like using the house bank for thrusters. I have 2 dedicated banks, one for each thruster in addition to the start batteries for each engine and a separate house bank. Also a separate generator start battery. Who knows if you have low voltage at the thrusters what the problems may present as.
 
My B & S thrusters have a separate 8D AGM batty.
IMO the high A draw of thrusters require high CCA vs AH of a lower longer draw.
My AGMs do both well but depending on chemistry and batty type your house may not be your best choice. With a helper, It should be fairly easy to measure V AT THE THRUSTER when they are operating! Then you have the facts to decide (maybe with mfg inputs) whether you need to change your thruster power source.
The best solution will likely be separate AGM batty bank located close to bow & stern.
 
My bow thruster runs off the house bank without issue, but my setup is likely different than OP has. I have double his battery bank with 10, 6 volt agm gc1 batteries connected with 4/0 cable jumpers and feed cables to the buss bars that are on the opposite side of the bulkhead from the thruster motor.
Stern thruster is similar, runs off the engine bank of 6 of the same gc1 batteries. All 4/0 cables. No low voltage drop outs on my electronics with this setup.
You can’t scrimp on wire size if you’re going to power the thrusters off the main battery banks. Most times though, it’s cheaper to add dedicated batteries at the thruster motors to keep cable lengths short.
 
I'm not sure which model size or motor voltage thruster the OP has, but for a 46' boat, I would hope it's 24 volts.

For my original setup, the builder installed a 12 volt system with a house bank about 25' away. Performance was bad as a function of a poor builder design. Replaced the motor with 24 volt unit and mounted the batteries 2' away. The difference was night and day for the same size thruster.

To the OP:
It would be helpful to specify model numbers and system voltage to offer you better opinions.

IMO, running thrusters off a house bank is probably going to induce problems from long cable runs and spiking voltage to other equipment on the house bank.

Ted
 
My first concern here is voltage drop. I don’t know the wire size or the run length so I don’t know if voltage drop is an issue but as already mentioned I would measure the voltage at the thruster while in use. I could be wrong but I am very suspicious of voltage drop issues when batteries are not located next to the thruster.
 
I'm not understanding why voltage drop would cause the drive coupler to break... twice.

Is something binding, or is there some sort of alignment problem? It's a new boat, right? So is the boat builder involved in this discussion since the installation is theirs?
 
I agree that voltage drop is nothing to do with the coupling shearing twice. Alignment has been checked and the current thinking is that it was caused by a lack of a delay in the unit when it goes from one side to the other ( which would be a product fault). The boatbuilder has been in the conversation and I understand that the installation was done under the supervision of Sleipner, so it is looking like Sleipner's issue. When they have worked the performance of the thrusters has been fine, so voltage drop at the thrusters doesn't seem to be an issue for their operation. What I am more concerned about is whether the associated large current draw and voltage hit on the house bank could cause other connected instruments to fail. Thanks to all for the comments, James
 
The closely located battery serving our bowthruster is fed from a main bank. It worked poorly until the battery was replaced with a start type battery specially recommended for thrusters. Thrusters are hungry albeit for short periods, it seems a distant house supply is not effective, a localized supply is. The supplier should have installed thrusters which function effectively, and a local power supply. Wonder if the remote battery source contributes to the thruster issues.
Is this the boat model?

AMG_6364.jpg
 
The closely located battery serving our bowthruster is fed from a main bank. It worked poorly until the battery was replaced with a start type battery specially recommended for thrusters. Thrusters are hungry albeit for short periods, it seems a distant house supply is not effective, a localized supply is. The supplier should have installed thrusters which function effectively, and a local power supply. Wonder if the remote battery source contributes to the thruster issues.

Ditto on start batteries. When I switched to 24 volts, everyone recommended deep cycle batteries, but the use function is clearly more like a start battery. First set lasted 8 years. :dance:

Ted
 
I'm not understanding why voltage drop would cause the drive coupler to break... twice.

Is something binding, or is there some sort of alignment problem? It's a new boat, right? So is the boat builder involved in this discussion since the installation is theirs?

I used to be an engineer for a computer company. We would always do the simple stuff first when working on a problem. The simple stuff in this case is voltage drop. Until you have confirmed that you actually have good voltage then everything thing else is suspect. Remember this is an electrical device that needs proper voltage. And it is easy to verify.
 
FWIW my bow thruster battery is an Optima Bluetop AGM, replacing similar. I thought the thruster was weak but it was the battery, demonstrated by the huge change in performance.
 
I'm not understanding why voltage drop would cause the drive coupler to break... twice.

Is something binding, or is there some sort of alignment problem? It's a new boat, right? So is the boat builder involved in this discussion since the installation is theirs?

These are retractable thrusters. I have no idea what confusion might occur with a voltage drop. It’s a simple potential to deal with first.

It’s also possible that the controllers are experiencing a voltage drop and causing a hard forward reverse situation.
 
I always use the KISS method of troubleshooting. Even though I may not think something like low voltage might affect the problem I still check it first when dealing with electrical issues. Surprising how often it is the root of the problem, loose, dirty connections. Bad battery or undersized cables can cause it. I hate to rip into a problem and start replacing expensive parts and then find it was a loose battery cable…
 
FWIW my bow thruster battery is an Optima Bluetop AGM, replacing similar. I thought the thruster was weak but it was the battery, demonstrated by the huge change in performance.

I use 2 Optima Redtop batteries in series for my bow thruster. They were great till the second half of the 8th year.

Ted
 
Every thruster I know of has a built in delay for direction changes. What I suspect is, low voltage is causing erratic operation. The system may sort of reboot during these low voltage events, or suffer other unforeseen problems like sudden stop and start in the same direction. This can shear the drive pins too.
I believe the builder may be more at fault as a result of poor installation/lack of adequate power supply.
 
I use 2 Optima Redtop batteries in series for my bow thruster. They were great till the second half of the 8th year.

Ted


My setup is one Odyssey Extreme grp 31 located about 1 ft away from the thruster. Works well so far.
 
Every thruster I know of has a built in delay for direction changes. What I suspect is, low voltage is causing erratic operation. The system may sort of reboot during these low voltage events, or suffer other unforeseen problems like sudden stop and start in the same direction. This can shear the drive pins too.
I believe the builder may be more at fault as a result of poor installation/lack of adequate power supply.

Every properly functioning install that I have used, seen or read about has been been with a dedicated battery in situ. Proper cabling etc. Not that remote batteries will not work, but why take a chance.
 
I used to be an engineer for a computer company. We would always do the simple stuff first when working on a problem. The simple stuff in this case is voltage drop. Until you have confirmed that you actually have good voltage then everything thing else is suspect. Remember this is an electrical device that needs proper voltage. And it is easy to verify.

I agree in principle, but the stuff you check should be guided by the problem symptoms.
 
But he said that the thrusters are powered from the house bank. So it begs the question, is there proper voltage at the thrusters when they are under load. It is very likely that with the long run the voltage may be low when the thrusters are activated. The cables may be undersized, add in any poor connection and with the long load it could easily cause low voltage. Whenever I do any electrical work I calculate the proper size wire/cable based on distance round trip and use the 3% voltage drop and not the 10% drop charts. Then I go at least one size larger so I get great voltage to the device. Everything electrical seems to work better with good voltage.
 
IMTRA https://www.imtra.com/products/sleipner is the Sleipner distributor. I have found them to be very helpful in the past with technical issues.

I have a feeling that the OP is not in the U.S.A.

It does not sound like a voltage drop to me. But its too easy to check it out!

Just 3 weeks ago I had a SE60 removed and a SE100 installed. N.E. Bow thruster installed it and I did the wiring. With a 40 foot boat they wanted and I did it a 24V thruster 2/0 wires at a total Pos & Neg wire length of 14 feet. With at least 800CCA.

I hope the OP used a 24V system with the right wire and battery bank?
 
I have a feeling that the OP is not in the U.S.A.
Not sure it matters, but easy to see James E is located in Broken Bay 20NM north of Sydney Australia. Beautiful area, with easy access to sailing inshore and offshore and excellent protected cruising grounds. Hope James keeps posting info on finding a solution and, welcome aboard!

My boat came with one (exhausted as it turned out) Optima serving the bowthruster, replaced with same taking advantage of existing securing and cabling. Marina mechanic said it was the ideal battery, lots of cca for size, but 2 were better and often fitted. So far we`re ok with one, and hoping for long battery life.
 
I have a feeling that the OP is not in the U.S.A.

It does not sound like a voltage drop to me. But its too easy to check it out!

Just 3 weeks ago I had a SE60 removed and a SE100 installed. N.E. Bow thruster installed it and I did the wiring. With a 40 foot boat they wanted and I did it a 24V thruster 2/0 wires at a total Pos & Neg wire length of 14 feet. With at least 800CCA.

I hope the OP used a 24V system with the right wire and battery bank?


Your opinion of NE Bow thruster?
 
Update - I have heard that Sleipner are aware that there is a weakness in the couplings on these models and that multiple boats are affected. Apparently they don't have an an engineering solution yet. Another replacement coupling was installed on my yacht and yesterday I ran the thruster for less than 2 seconds at about a quarter of maximum power. It sheared the coupling. I have not received any formal communication from Sleipner and no product recall has been communicated. In the interests of safety I suggest that anyone with these retractable thrusters be aware that they are liable to sudden failure and not rely on them until there is a proper communication from Sleipner on the issue.
 
N.E. Bow Thruster was great to work with. They where coming out of Conn and the boat was 8 miles north of Boston and they were 10 minutes late. Just 10, couldn't be happier!! Than they went though everything with me. Even took out some rough spots in the tunnel.

I highly suggest them.
 

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