Bow Thruster

[Capttug]

I have a 430 2002 Aft deck Trawler with a bow thruster. I was wondering how many people have a separate dedicated battery for theirs. I do not. recently when ever I engage the Thruster, my Gps and Auto Pilot shut down. Would a separate battery solve my problem?

Thanks,

Bill DeStacy
Amore

Goose Bay Marina
Potomac River

 

[ddalme]

Yes, your pulling to many amps of the set up you have now.

 

[MYTraveler]

or your batteries are weak.

 

[kthoennes]

I have a 430 2002 Aft deck Trawler with a bow thruster. I was wondering how many people have a separate dedicated battery for theirs.

We don't have a bow thruster, but the previous owner installed a separate battery for the windlass for the same reason. Our chart plotter takes a long time to get an initial fix so I tried turning it on well before we started the engines and cast off. Nope. As soon as I hit the engine ignition switches, the plotter goes off and has to start all over again. Same thing with your thruster I expect, sudden heavy battery load and the voltage dips.

 

[Carolena]

Our bow thruster runs off the house bank. When we surveyed the boat, the surveyor noted that the batteries (4 six volt golf cart batteries) were OK but nearing end of life. The following summer we experienced the same thing as you - electronics restarting when we used the thruster. We took that as a sign that the batteries were ready to be replaced, which we did. That solved the problem and we haven't experienced any issues for the past three years since replacing the battery bank.

 

[N4712]

Our boat has two 8D's for each thruster that are tied into the main house bank. I'd look at locating a battery local to the and either put a
Small charger on it or hook it into the house bank.

 

[DavidM]

On my Mainship 34T, 2006 model, the bow thruster was powered from a dedicated 4D located in the engine room and charged through a battery isolator. In that case it could not affect the instruments.


Yours is obviously powered by the same bank that runs the instruments. My guess is that bank is weak and replacing the batteries will solve your problem.


But if not or you just want to install a dedicated battery, there are two ways:


Do what Mainship did for my boat and install a 4D or similar in the engine room and isolate it from the others. You already have heavy 2/0 or so wire to the bow so that is the easiest option.


But if you want the battery in the bow then look up in the projects section on yandina.com how to do it.


In either case you need to isolate it and Yandina's combiner is a better solution than a diode isolator.


David

 

[psneeld]

Something needs adjusting..either larger cables, better charging or a battery closer to the load....


Check, decide, fix and enjoy.

 

[Ski in NC]

I put a dedicated battery up near the thruster. To charge ran a #10ga pair from house batt, but put a relay and two diodes in the circuit so when thruster is energized, relay disconnects the link to the house batt. This prevents a volt dip and also limits current in the 10ga link. It's fed through I think a 15a breaker.

System works very well. I wanted to be able to charge thruster batt without needing AC power.

 

[Steve]

My house bank, two 8Ds, also powers the thruster and engine starter. So far no problem with any of them. And I am not embrassed to use the thruster frequently, so far it has not caused the chartplotter to shut down. I do have a separate battery for the generator.
Has your boat done this, shut down the plotter and autopilot, since you got it or is this a new problem?

 

[Poach]

Separate 24 v batt, separate charger. Separate start battery for mains. Separate start battery for gen set. I thought about a separate battery for the icemaker, but you have to quit somewhere.

 

[ARoss]

We have a separate 12v battery for the thruster, and it also powers the windlass. Mounted forward under the vberth decking, making short cable runs to both. Hopefully I'll never need to see if the battery can run both at once....

 

[High Wire]

... or your connections need cleaning.

 

[Talonewo]

I have two DC systems, 32V and 12V and then installed a 24V bow thruster. I went with two group 29 batteries in series dedicated for just the thruster and installed a separate DC to DC charger.

 

[Codger2]

Recently when ever I engage the Thruster, my Gps and Auto Pilot shut down. Would a separate battery solve my problem?

Yes...I have 4 six volt golf car batteries for my bow thruster and they have their own charger.

 

[cardude01]

Engaging my bow thruster would also turn off my plotter. Thruster runs off the house bank.

I replaced my weak house batteries and no problem now.

 

[markpierce]

Engaging my 24-volt bow thruster has no effect on other electronics. It doesn't have its own dedicated battery.

 

[MYTraveler]

Engaging my 24-volt bow thruster has no effect on other electronics. It doesn't have its own dedicated battery.

Same here. Also unaffected by anchor windlass, SSB and everything else, although if I don't have shore power my genset (and therefore something like 300 amps of charger) is always on.

 

[SCOTTEDAVIS]

Just a note, check if the cable used for the BT is the size required by the manufacture of the BT.

The length of run is the total round trip not just one way and often I see builders think this as a good place to save a few bucks as wire of the required size is not cheap.

With any amount of run you will want AWG 2 as the smallest wire for a small (4 or 5 hp) BT (mine came with awg 4) most larger units and you are into heavy cable 1/O or 2/O perhaps even larger.

When I put in awg 2 from the 4 it was like a new thruster. I was also cheaper then adding a battery and charging system, and no maintenance.

 

[FlyWright]

Just another angle here to the great advice above:

It's not clear if this is a 12V thruster, but if it is, have you considered wiring it to your start battery? I did this for my windlass b/c the engine is always running when using the windlass and it would be the same for a bow thruster operation. It isolates large loads from your house bank and provides power from a battery that in my case (8D) is oversized for the task of just starting the engines.

It's better that your electronics not be subjected to the voltage surges and sags that you're seeing. Granted, with a healthy house bank, you'd get by with it as is, but as the bank weakens, the problems surface.

If it's a 24V thruster and 12V start battery, then...

 

[Heron]

Just a note, check if the cable used for the BT is the size required by the manufacture of the BT.

The length of run is the total round trip not just one way and often I see builders think this as a good place to save a few bucks as wire of the required size is not cheap.

With any amount of run you will want AWG 2 as the smallest wire for a small (4 or 5 hp) BT (mine came with awg 4) most larger units and you are into heavy cable 1/O or 2/O perhaps even larger.

When I put in awg 2 from the 4 it was like a new thruster. I was also cheaper then adding a battery and charging system, and no maintenance.

This....My wiring is as big as my thumb... No shut down or thermal issues whatsoever..

 

[MYTraveler]

I don't think it is a wiring problem with your thruster. If anything, inadequate wiring will reduce the current flow. Your electronics are shutting down because the voltage at the battery is getting too low because there is too much current demand, not too little. I am back to my original suggestion -- your batteries are weak, either under charged (verify that they are reaching full charge and that you have this problem when fully charged) or worn out (ie, significantly impaired capacity). You can confirm battery capacity with a load test. If they are proven bad, and if you have the facility, try equalizing them. Otherwise, I bet everything will be back to normal as soon as you replace the batteries. For what it is worth, lots of boats don't have a separate bow bank for the thruster and work just fine.

 

[SteveD]

The best batteries for DC thrusters are thin plate AGM batteries, such as Odyssey's or Die Hard Platinums (the same battery with a different label). They are capable of supplying tremendous amounts of current for short periods, which is just what a thruster needs. I have two of these (Group 31) in series to run a 24 volt thruster. The batteries are right next to the thruster, so there is no voltage drop through the short 0000 cables. The whole thing is charged with a Sterling DC->DC charger and it works like a charm.

 

[BlueYonder]

I have 3 of the Diehard Platinum group 31 in my start/thruster bank. Works very well with bow and stern thrusters going at the same time.

 

[porman]

Capttug, is your boat a Mainship 430 aft cabin trawler?

 

[timjet]

I had the same issue a couple of years ago. It was addressed at TF here: http://www.trawlerforum.com/forums/s4/power-electronics-during-engine-start-10624.html

And here: http://www.trawlerforum.com/forums/s4/dc-dc-converter-10555.html

Basically you might want to consider a DC to DC converter for your electronics or a dedicated battery for your electronics. A dedicated battery for your electronics has the advantage of allowing you use of all the batteries on your house bank for the thruster which should make the thruster more realiable. A dedicated electronics battery would be a lot easier to wire just requiring a charging wire from your house or engine start bank with a diode.

I choose to just turn off the electronics before starting the engines, it's now habit so no problem.

 

[SCOTTEDAVIS]

I don't think it is a wiring problem with your thruster. If anything, inadequate wiring will reduce the current flow. Your electronics are shutting down because the voltage at the battery is getting too low because there is too much current demand, not too little. I am back to my original suggestion -- your batteries are weak, either under charged (verify that they are reaching full charge and that you have this problem when fully charged) or worn out (ie, significantly impaired capacity). You can confirm battery capacity with a load test. If they are proven bad, and if you have the facility, try equalizing them. Otherwise, I bet everything will be back to normal as soon as you replace the batteries. For what it is worth, lots of boats don't have a separate bow bank for the thruster and work just fine.

Inadequate wiring will increase the current draw as the wattage of the load is not changed and you will increase the draw by heating up the wiring while reducing the voltage to the motor (still requiring the same wattage draw) thus drawing more from the battery's.

It has been stated correctly that BT's should be wired to the starting battery's not the house as they are like a starter, demanding a high current draw for a short time, not what deep cycle battery's like to do.

Too small of a bank of brand new deep cycle battery's may not be able to provide the short term current requirements as the surface area of the plates is to low to provide the burst needed even fully charged and new.

The real difference between starting and deep cycle batteries is starting has more thinner plates giving a greater surface area for more current (more conversion area) in the short term. DC have thicker (denser) plates but less of them (given same size as starting) for longer low current production as their deeper lead plates provide more (slower but longer) chemical reaction between the water/acid conversion.

The BT and windless is mostly used when the engine is running so the higher voltage provided by the alt. actually reduces the in-use wire size amount by 15% so is a bit of a bonus (14.8v is 15% greater then 12.6v).

BT should be on starting battery's as well as the windless or a separate starting battery not on house or deep cycle.

BT must be wired with the proper cables or larger and all connections must be perfect and clean.

 

[SCOTTEDAVIS]

I had the same issue a couple of years ago. It was addressed at TF here: http://www.trawlerforum.com/forums/s4/power-electronics-during-engine-start-10624.html

And here: http://www.trawlerforum.com/forums/s4/dc-dc-converter-10555.html

Basically you might want to consider a DC to DC converter for your electronics or a dedicated battery for your electronics. A dedicated battery for your electronics has the advantage of allowing you use of all the batteries on your house bank for the thruster which should make the thruster more realiable. A dedicated electronics battery would be a lot easier to wire just requiring a charging wire from your house or engine start bank with a diode.

I choose to just turn off the electronics before starting the engines, it's now habit so no problem.

Tim, did you ever get that unit to work for you?

 

[timjet]

Tim, did you ever get that unit to work for you?

No I did not. I did not properly troubleshoot it sufficiently to determine the problem as I had a laundry list of other issues to deal with. I will eventually get back to it.