Thrusters

[NEDBETTY]

I have a 2014 CB31
Tonight we had a Med to high current and it took me 30 min to dock at my pier
The bow and stern thrusters battery lasted maybe 15 min Use and on and off use at 15 to 30 seconds Each time then died batteries are new but boat sat for 4 days. It I had the one 30 amp plugged in not sure if that is charger side? Its the plug That does not power the a/c
I had thrusters on prev boat and no issues I think these that came with tug are undersized

Any suggestions other than learning to be a better pilot on one screw

Thanks

 

[Karll]

So far my thrusters have worked for me but my marina is a dry storage marina and I have an R29 and retrieval dock requires us to swing around and stern towards the lift. It’s a small area between the launch and retrieval dock and is usually not a problem but it is in a dredged area of a sleugh and when the current is running and the wind blowing it can be a challenge.

 

[Mr. Ed]

I have noticed that whenever I engage either of my thrusters (or both) that the engine (at idle) starts to labor and the rpms go down a bit. The extra drain on the alternator is really evident. And it's immediate. There isn't a lot of reserve power in the thruster battery.

 

[NEDBETTY]

I was told to start genset and that will give thruster max voltage?

 

[iggy]

Its sounds like the battery is ether undersized or a new one is needed. From some of the above post. I would do a load test on the battery first

 

[iggy]

I was told to start genset and that will give thruster max voltage?

The genset is only going to turn the charger on. So it not going to add much more. You would be better off installing a bigger alternator.

But again a bigger or new battery could be needed.

 

[bill46]

First how old is the battery, replaced one on my 2014 R31CB in 2018. Second they are not meant to be run 15 minutes. Instructions say maximum run 3 minutes, then thermal breaker may shut down.
I love bow thruster, but can get much more stern motion setting the rudder and giving a quick burst of forward power.

Sometimes there is just too much wind or current. I had a time could not line up, but remembered a boat always goes towards wind in reverse, drivers until dock was upwind and backed close enough to pass a line and 7 dockhands brought us in!

 

[NEDBETTY]

Thanks everyone, All batteries Are sealed ones and 6 months new
Didn’t run 15 min straight it was maybe 1 Min burst then rest and then bursts again
I’m pretty sure battery was low as I now know since last posting I had land current plugged into wrong plug so not the one that runs charger oops

Thanks

 

[iggy]

Thanks everyone, All batteries Are sealed ones and 6 months new
Didn’t run 15 min straight it was maybe 1 Min burst then rest and then bursts again
I’m pretty sure battery was low as I now know since last posting I had land current plugged into wrong plug so not the one that runs charger oops

Thanks

But the Alt should have charged up all the batteries? Yes?

 

[NEDBETTY]

I had the boat at the dock for a week and only plugged into one plug and it was not the plug that operates the charger so I think I drained that battery pretty well and I only ran it for 15 minutes to the house from the marina where it was being serviced so that probably wasn’t enough time I could barely see the lights after trying to thrusters a few times and then I started the generator and the thruster control lights came right on so now that I know the right combination for charging

 

[ALICE J]

I have paralleled my thruster battery with the house batteries, so I get extra amps for either the thruster or the house lights. Have you checked the terminals for corrosion?

 

[NEDBETTY]

Thanks for your reply.
No corrosion they are all new.
Think I just had the batteries run down as I was plugged in to wrong plug the A/C side and not house side for several days!
I am learning every day.

Best,
Ned

 

[Hydraulicjump]

Others will almost certainly chime in on this. And perhaps I am misreading your comment.

The thrusters are designed to be used in short bursts. If you lay on them for more than about five seconds (again, others will have a different response), the amp draw is so large that the voltage on your thruster battery will drop dramatically. Heck, your whole battery bank will lower voltage in response to this. You will hear a "beep" that tells you your voltage is dropped below acceptable levels. And you run the risk of burning out your thrusters.

I have found in both tugs we have owned that the alternator cannot keep up with the thrusters--especially both thrusters at the same time--and neither can the thruster/windlass battery. And I think this is true for most boats. Listen to the big ones coming into the dock. Even with their immense alternators, they run their thrusters in short bursts, rather than running them hard continuously.

So my advice--which I hope you are soliciting, but is worth all that you are paying for it--is to take a more aggressive throttle approach. Too many of us (meaning me) are idle-forward types in tough docking situations. We are all taught that "slow is pro" for close quarters maneuvering. But these tugs have rudders the size of a handkerchief, and for those of us fallen sailors, this is a real struggle. Bursts of forward (with the wheel hard over) and reverse are needed to move these boats, along with bursts of thruster to help out.

And of course, if you want a BIG thruster battery, just parallel your batteries before you dock, remembering to switch them back afterward.

I laugh at the early Ranger Tug YouTube videos of a decade ago where they state that their bow and stern thrusters "take all the drama out of docking." Well, maybe on a day with no wind and no current. There is always drama. Especially if everyone on the dock is watching you.

Enjoy your boat. The more you enjoy it the less you will use the thrusters. That is the key.

Jeff