Bow thruster

[marioxp]

I am looking for a bow thruster for my Bavaria 36.
How satisfied are you with your bow thrusters?  Does anyone have any recommendations and advice on what to look at.For now,
I received a recommendation from the seller for Quick BTQ 185-75 and for Max power CT80.  But it's the sales people who not really use it.

[Happysailor]

Hi,

I also had a bowthruster installed on our boat. First I looked at the “original” fitted Sidepower. Then I came across the Vetus Bowpro B 110 kgf. This is a proportional bowthruster which works very good. The built in thyristor control converts 24 Volts DC (also steps up 12 Volt boat power to 24 Volt for charging of the fitted additional batteries) to AC and the motor is a brushless AC motor. So no more carbon dust and no more trouble with brushes. The control is very accurate as it is stageless proportional. So if not a lot of power is needed you can just gently use the thruster… and keep your neighbors asleep at early departure..😂

https://webshop.vetus.com/en/product/bow-pro-boosted-thruster-110-kgf-12-24-v-185-mm-tunnel

Yes, it is a bit more expensive than the usual full on/ off thrusters, but this is really next gen and worth the money. You can also run it for longer time, e.g. to swing around in narrow spaces on the thruster only. On our Bavaria 41 usually a 90 kgf is fitted and found this when I hired a boat for testing, a little light in more severe and windy conditions. So if you have the money and space to spare, try to fit a larger type than you would anticipate on the specs of the thruster manufacturer. (So in your case 90 kgf) The times when you would like to rely on your bowthruster most are not the light conditions…

Good luck making your choice!

[tiger79]

My Cruiser 37 has a factory-fitted SidePower SE60 thruster, one step down from the two you've been recommended.  It's been fine for 10 years, with no sign of carbon dust and no problems with brushes.  I had a thermal switch fail, but spares are easily available.  The equivalent SidePower to the ones you've been recommended would be the SE80.

Happysailor mentioned proportional control and I agree this would be an advantage in some circumstances.  However, it is very expensive - more than double the price!  I was contemplating converting mine to proportional control until I found out the cost.

One thing you need to do is to choose your preferred control system (joystick, buttons, etc) and get a firm quote which includes everything you need to make it work (including installation if you're not fitting it yourself).  You might like to include a wireless remote control, which can be handy when you're moving around the boat during mooring.

[symphony2]

Another vote for a Sidepower SE60. I had one on my B33 factory fit. More than enough for your B36. You may have to move or modify your forward water tank if you have one. best accessory is the Sidepower wireless remote which also does the anchor windlass. Expensive but worth it . The other thing you will have to consider is whether you power it from the existing batteries which means running heavy cables through the boat or fit a dedicated battery charged by a DC/DC from the engine start battery. this only needs 16mm cables - much easier to run.

[GeoffV]

Same on my Cruiser 37 plenty of power available.

[marioxp]

I took your advice and the Sidepower SE60/180 12V is on the way. Thank you!

Someone skilled will install the tunnel for me, and I will do the wiring.

The idea is to put the additional battery as close to the bow thruster as possible., to keep the thick cables as short as possible.
The manufacturer recommends a switch that goes to the plus cable. It can be manual or automatic, automatic is quite expensive, around 500 euros. if switch is manual it needs to be easily accessible which means I'll have to put it somewhere away from the bow thruster which spoils my idea of ​​short cables.
How is it with you?

Next thing how big should the extra battery be?

And the last question.

How to connect to the existing electrical system?

I currently have, engine battery and house battery (2x140Ah), two power sources, shore power (2 outputs) and an alternator with a Victron fed splitter (2 outputs).

At first I thought of just connecting the house battery to the thruster battery with a 25 mm2 cable. There will never be a big difference in voltage between these batteries, so there will never be a big current (I would check this in reality).
The disadvantage is that the thruster battery would be discharged as the home battery is discharged. This could be prevented by adding charging relay in series, so that these two batteries would be connected only when charging.

Second option is to put a DC-DC charger, but this is a much more expensive option.

The third option is to replace the splitter and shorepšower charger with models with three outlets, this is the most expensive option.

I listen to your ideas and suggestion.

[symphony2]

Keep it simple! 30A DC/DC charger from the engine start then 16mm cables to a bow battery of around 100ah, suitably fused - the charger instructions will tell you. I used a Sterling charger because I got a good price, but if doing it again I would use a Victron.  Then a 110A isolator switch in the +ve to the thruster control box.