Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 28-02-2016, 00:55   #1
Registered User

Join Date: Sep 2015
Boat: Oceanis 40
Posts: 189
Separate bow thruster batteries - Why don't I have them?

Hi there,

I have noticed that several other Beneteau Oceanis 40's have two additional batteries on either side of their bow thruster (for the bow thruster).

I guess mine runs off our service batteries or start batteries.

Whats the deal there? And should I add dedicated thruster batteries?
AFKASAP is offline   Reply With Quote
Old 28-02-2016, 07:04   #2
CF Adviser
 
Pelagic's Avatar

Join Date: Oct 2007
Boat: Van Helleman Schooner 65ft StarGazer
Posts: 10,280
Re: Separate bow thruster batteries - Why don't I have them?

It doesn't really matter either way ....but I prefer to keep all the weight of the batteries further aft close to their charging and distribution components.... Bus bar etc.

By using the house bank...you just run suitable cable to the thruster up forward.
That is what I have.
Pelagic is offline   Reply With Quote
Old 29-02-2016, 16:21   #3
Registered User

Join Date: May 2011
Location: Ithaca, NY
Boat: Pearson Wanderer 30
Posts: 45
Re: Separate bow thruster batteries - Why don't I have them?

The main reason for having batteries near the bow thruster is probably to cut down on the length and size of the conductors that provide power-thrusters draw a lot of current, relatively speaking. If you already have batteries installed aft and, presumably, correctly sized conductors running to the bow then there is nothing to be gained by adding a dedicated battery forward unless you find yourself drawing down the house or starting bank to an unacceptable degree because of how much you use the thruster. Even then, it makes more sense to simply add an additional battery aft where it can be charged by the alternator/genset/charger along with the others.
__________________
As eccentric as my boat.
Crazer is offline   Reply With Quote
Old 29-02-2016, 17:01   #4
Registered User
 
markpierce's Avatar

Join Date: Aug 2010
Location: Central California
Boat: M/V Carquinez Coot
Posts: 3,782
Re: Separate bow thruster batteries - Why don't I have them?

Having a 24-volt system, may have its advantages. ... Both starting and house batteries are about twelve feet from the thruster. Not sure which bank operates the thruster. Whatever, no lack of thruster power. (I'd lay my bet on the house batteries.) Good question for the builder.
__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 29-02-2016, 17:20   #5
Registered User
 
ontherocks83's Avatar

Join Date: Aug 2013
Location: Warwick RI
Boat: Catalina 30
Posts: 1,873
Re: Separate bow thruster batteries - Why don't I have them?

As long as you have the correct size properly fused cable it shouldn't be a problem. I personally like only having 2 banks. A house bank and an emergency starting bank. Essentially everything runs off the house bank including starting. The back up bank gets charged by an echo charger and is only used should the house get drained too far down (which should never happen) or if there is a short in the house and or some other problem. This keeps it very simple to charge, maintain, and trouble shoot.

What gauge cable do you currently have going to your thrusters and how Long of a round trip run is it?
__________________
-Si Vis Pacem Parabellum
-Molon Labe
ontherocks83 is offline   Reply With Quote
Old 29-02-2016, 23:15   #6
Registered User

Join Date: Sep 2015
Boat: Oceanis 40
Posts: 189
Re: Separate bow thruster batteries - Why don't I have them?

I don't know what cable or how long it is. When I get back to the the boat I will check. I hope it is going to the house batteries.

Beneteau Oceanis 40 - 2008
Netherlands
AFKASAP is offline   Reply With Quote
Old 01-03-2016, 00:41   #7
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,764
Re: Separate bow thruster batteries - Why don't I have them?

The other reason is to use start batteries instead of deep cycle batts. They produce short term heavy currents better than deep cycle batts.

But I agree with Pelagic -- it's not good for weight distribution to have batts up in the bow. With 24v and enough battery capacity it's not the end of the world, either to use your regular house batts, or somewhat longer cable runs.

The very large power draw of the thruster will cause voltage sag -- a combination of voltage sag from cables and from the batts themselves. If you have large battery capacity there will be less voltage drop there, so the cables don't hurt you as much.

Adequate cables also help. Obviously it's much harder to move a lot of power over any distance, at 12v. 36v or 48v would be still better. In my opinion 12v is really not suitable for this job.
__________________
"You sea! I resign myself to you also . . . . I guess what you mean,
I behold from the beach your crooked inviting fingers,
I believe you refuse to go back without feeling of me;
We must have a turn together . . . . I undress . . . . hurry me out of sight of the land,
Cushion me soft . . . . rock me in billowy drowse,
Dash me with amorous wet . . . . I can repay you."
Walt Whitman
Dockhead is offline   Reply With Quote
Old 01-03-2016, 01:00   #8
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,764
Re: Separate bow thruster batteries - Why don't I have them?

Quote:
Originally Posted by ontherocks83 View Post
As long as you have the correct size properly fused cable it shouldn't be a problem. I personally like only having 2 banks. A house bank and an emergency starting bank. Essentially everything runs off the house bank including starting. The back up bank gets charged by an echo charger and is only used should the house get drained too far down (which should never happen) or if there is a short in the house and or some other problem. This keeps it very simple to charge, maintain, and trouble shoot. . . .
That looks like a good system. Even simpler would be a completely separate start bank with its own alternator and charger. Then your emergency starting is from the house bank, rather than vice versa, but an engine start batt which is separately charged and never used for anything else is very unlikely to ever need any backup.

My boat is somewhat more complex because house is 24v and engine and generator start 12v. Generator and engine each have their own completely separate start banks and charging systems. The start batts are in the same box and back up each other.


In seven years with this boat, I've only needed backup starting once. For some reason which I have never figured out, every battery on the boat ran down while I was off the boat for about a month. I arrived on my mooring (no shore power) one very cold evening and couldn't get either main or generator to start, and the house batts were dead (otherwise I could have pulled one of those out). I was fairly desperate. Finally I took the last good battery -- out of the dinghy. A tiny start battery for the 25hp outboard, but it was just enough. Added it to the run down main engine battery, and that started. After that, I was able to bring everything back to life. and the incident never repeated. Weird.
__________________
"You sea! I resign myself to you also . . . . I guess what you mean,
I behold from the beach your crooked inviting fingers,
I believe you refuse to go back without feeling of me;
We must have a turn together . . . . I undress . . . . hurry me out of sight of the land,
Cushion me soft . . . . rock me in billowy drowse,
Dash me with amorous wet . . . . I can repay you."
Walt Whitman
Dockhead is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale: Vetus BOW-160 bow thruster motor 157hunt Classifieds Archive 0 28-10-2015 07:19
Dead Batteries -- Blast Them or Coddle Them? Dockhead Electrical: Batteries, Generators & Solar 36 02-06-2012 17:07
Batteries: Do I Have to Change All of Them? Alecadi Electrical: Batteries, Generators & Solar 29 21-05-2011 11:01
Can I separate two pairs of batteries? Stevebellevue Electrical: Batteries, Generators & Solar 4 03-04-2011 07:24
Adding Bow Thruster and Windlass . . . What to Do with Batteries geoffr Electrical: Batteries, Generators & Solar 26 20-09-2010 04:26

Advertise Here


All times are GMT -7. The time now is 01:34.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.