Notices

more batteries or not

Old 09-18-2012, 03:53 PM
  #1  
Junior Member
Thread Starter
 
Join Date: Feb 2012
Posts: 28
Default more batteries or not

installing a bow thruster and need to know if a third battery is necessary.30 ft boat yes or no some one tell me intellegently ,so far no one makes scence

Last edited by forbones; 09-19-2012 at 06:27 PM.
forbones is offline  
Old 09-18-2012, 04:11 PM
  #2  
Senior Member
 
Join Date: Jan 2007
Posts: 3,169
Default

Doesn't the bow thruster manufacturer have recommended installation instructions? What does that document say?

Many times the bow thruster is powered by 24V, from two batteries in-series.
wingless is offline  
Old 09-18-2012, 04:18 PM
  #3  
Senior Member
 
Join Date: Feb 2011
Location: Newport Beach, CA. USA
Posts: 1,327
Default

Originally Posted by forbones View Post
installing a bow thruster and need to know if a third battery is necessary.30 ft boat
Your current batteries are ?

Group 24 ?
27?
29?
31?
Rico2 is online now  
Old 09-18-2012, 04:44 PM
  #4  
Senior MemberCaptains Club Member
 
Join Date: Sep 2002
Location: Puget Sound
Posts: 869
Default

Unless your batteries are already forward you don't have room for a battery by the thruster it is easier and more efficient to use a dedicated battery for the thruster. The caveat is that the dedicated battery must be located by the thruster this will keep the 2-4ought cable to a minimum length. You can charge that battery with an echo charger, VSR or dedicated 120 volt charger. The thruster battery should be a high cranking amp type. I would use a sears platinum agm group 31, they have plenty of power and can be mounted in almost any position..
finadict is offline  
Old 09-19-2012, 07:22 AM
  #5  
Senior MemberCaptains Club Member
 
Join Date: Jan 2007
Location: Beaufort, SC
Posts: 579
Default

Thrusters require very heavy cables that can be expensive. It is usually cheaper to have a dedicated battery adjacent to the thruster and the reduced voltage drop will give you better performance.

An economical 10 gauge charging line with a Combiner100 for about $60 will take care of charging.
yandina is offline  
Old 09-19-2012, 09:00 AM
  #6  
Senior Member
 
Join Date: Aug 2012
Posts: 2,418
Thumbs down

Originally Posted by yandina View Post
Thrusters require very heavy cables that can be expensive. It is usually cheaper to have a dedicated battery adjacent to the thruster and the reduced voltage drop will give you better performance.
This much is true, as far as it goes.


An economical 10 gauge charging line with a Combiner100 for about $60 will take care of charging.
This is more of your incessant self-promoting spam. Please knock it off.





Itteldoo is offline  
Old 09-19-2012, 02:29 PM
  #7  
Senior Member
 
Join Date: Apr 2009
Location: The wilds of Michigan
Posts: 753
Default

A better solution in my mind is to add a thruster battery up front - wired in parallel with your main battery set...
Schematically (poorly done) Assuming two batteries in the house set and one up front

house set _________________________bow_____ motor
[pos side] Bat+BAT+++++++++++++++BAT+++thruster POS
[neg side] Bat-BAT--------------------------BAT-----thruster NEG

The cables between the house and bow batteries do not have to be as heavy due to part of the energy is stored up front... Then the cables from the bow battery to the motor can be heavy (but short)
denny-o is offline  
Old 09-19-2012, 02:39 PM
  #8  
Admirals Club
 
Join Date: Jun 2006
Location: Up North Wis & Marco Island, FL
Posts: 2,798
Default

I would not run parallel batteries without heavy cables between the two.
If not, it defeats the purpose of having a close by battery and it will also draw high amps from stern battery and overheat the cables.
deltarome is offline  
Old 09-19-2012, 05:15 PM
  #9  
Senior Member
 
Join Date: Aug 2012
Posts: 2,418
Thumbs down

Originally Posted by denny-o View Post
A better solution in my mind is to add a thruster battery up front - wired in parallel with your main battery set...
That would defeat the primary purpose of locating a (semi-)dedicated battery in close proximity to the thruster.


The cables between the house and bow batteries do not have to be as heavy due to part of the energy is stored up front... Then the cables from the bow battery to the motor can be heavy (but short)
ABSOLUTELY NOT!!!


First, the longer the cables, the HEAVIER they need to be, not lighter.

Second, and more ominously, if the batteries are in parallel, then the load (i.e., the thruster motor) will (attempt to) draw from both batteries equally. To the extent that the series resistance of those long and "not as heavy" cables interfere with this, those same cables will heat up -- possibly dangerously. This could EASILY set the boat on fire.

DO NOT DO THIS!!!!



Itteldoo is offline  
Old 09-19-2012, 06:47 PM
  #10  
Admirals Club Admiral's Club Member
 
Join Date: Jun 2008
Location: Plymouth Ma.
Posts: 8,037
Default

If you use a dedicated battery up in the bow and only want to charge it, then use a thermal breaker at both ends of the cable rated below the wire size used. Even if you use a VSR, and 10 ga wire, if the VSR fails closed and the battery up forward the amperage will flow from the source( whatever battery is charging the thruster bank, usually an engine battery because type would be the same) and let the smoke out of the sub sized wire real quick. Point being circuit protection is critical to the installation.

How far from the existing batteries is the thruster? And how many of what kind dip you have on board? Twin screw? House bank? All this is very important on setting up.
CMEBoston is offline  
Old 09-20-2012, 09:53 AM
  #11  
Senior MemberCaptains Club Member
 
Join Date: Jan 2007
Location: Beaufort, SC
Posts: 579
Default

Quote:
The cables between the house and bow batteries do not have to be as heavy due to part of the energy is stored up front... Then the cables from the bow battery to the motor can be heavy (but short)
ABSOLUTELY NOT!!!


First, the longer the cables, the HEAVIER they need to be, not lighter.

Second, and more ominously, if the batteries are in parallel, then the load (i.e., the thruster motor) will (attempt to) draw from both batteries equally. To the extent that the series resistance of those long and "not as heavy" cables interfere with this, those same cables will heat up -- possibly dangerously. This could EASILY set the boat on fire.

DO NOT DO THIS!!!!



10 gauge cables are quite sufficient for charging. They can carry 50 amps continuously that will fully charge the thruster batteries in an hour or two or top them off in normal circumstances in 10 minutes.

If you are going to run cables heavy enough to run the thruster you don't need batteries adjacent to it and you are going to get poor performance due to voltage drop in the cables even after spending $500 on them.

The charging line will NOT overheat. The Combiner100 will limit the current flowing from the starting battery to the thruster battery to a safe level.
yandina is offline  
Old 09-20-2012, 10:16 AM
  #12  
Senior MemberCaptains Club Member
 
Join Date: Feb 2005
Location:
Posts: 13,052
Default

Originally Posted by Itteldoo View Post
This much is true, as far as it goes.

This is more of your incessant self-promoting spam. Please knock it off.

It is perfectly good information. Why should it not be provided?

If a vendor has some good information should he not be sharing it? I imagine that the guy looking for the help will be appreciative,
jethro1 is offline  
Old 09-20-2012, 10:19 AM
  #13  
Senior MemberCaptains Club Member
 
Join Date: Feb 2005
Location:
Posts: 13,052
Default

Originally Posted by Itteldoo View Post
That would defeat the primary purpose of locating a (semi-)dedicated battery in close proximity to the thruster.

ABSOLUTELY NOT!!!

First, the longer the cables, the HEAVIER they need to be, not lighter.

Second, and more ominously, if the batteries are in parallel, then the load (i.e., the thruster motor) will (attempt to) draw from both batteries equally. To the extent that the series resistance of those long and "not as heavy" cables interfere with this, those same cables will heat up -- possibly dangerously. This could EASILY set the boat on fire.

DO NOT DO THIS!!!!
Why are you shouting at us?
jethro1 is offline  
Old 09-20-2012, 11:03 AM
  #14  
Senior Member
 
Join Date: Aug 2012
Posts: 2,418
Default

Originally Posted by CMEBoston View Post
What the hell is that?^^^^^^^^^
I assume you were referring to the completely over-the-top profane and abusive posts that the moderator has since removed.

However, now that those posts have been removed, it now looks like you're asking about MY post.

Just wanted to clear that up.



Itteldoo is offline  
Old 09-20-2012, 11:07 AM
  #15  
Admirals Club Admiral's Club Member
 
Join Date: Jun 2008
Location: Plymouth Ma.
Posts: 8,037
Default

Originally Posted by Itteldoo View Post
I assume you were referring to the completely over-the-top profane and abusive posts that the moderator has since removed.

However, now that those posts have been removed, it now looks like you're asking about MY post.

Just wanted to clear that up.


Yeah, I saw it all on forumrunner e so I could not figure out what the hell was going on..........
CMEBoston is offline  
Old 09-20-2012, 11:34 AM
  #16  
Senior Member
 
Join Date: Aug 2012
Posts: 2,418
Default

Originally Posted by yandina View Post
Originally Posted by Itteldoo View Post
ABSOLUTELY NOT!!!

First, the longer the cables, the HEAVIER they need to be, not lighter.

Second, and more ominously, if the batteries are in parallel, then the load (i.e., the thruster motor) will (attempt to) draw from both batteries equally. To the extent that the series resistance of those long and "not as heavy" cables interfere with this, those same cables will heat up -- possibly dangerously. This could EASILY set the boat on fire.

DO NOT DO THIS!!!!
10 gauge cables are quite sufficient for charging.
Quite possibly so, depending on the charge rate and the length of the run; but that is not what "denny-o" was talking about.

He was specifically suggesting that two (large-ish) batteries in significantly different physical locations in the boat be placed in parallel, and left that way, even when being drawn from by the thruster motor. He further suggested using very light wiring to accomplish this, citing a completely imaginary (and VERY wrong) theory to support this. That is a disaster in the making. No question about it.


They can carry 50 amps continuously that will fully charge the thruster batteries in an hour or two or top them off in normal circumstances in 10 minutes.
This would depend on several other factors, most notably including the length of the wire run and the MAXIMUM possible charging current. Refer to http://www.acbsphl.org/Tips_and_hints/ABYC_Wiring.htm (among other possible sources) for the applicable MINIMUM standards. But do note the example given there of a 10-amp bilge pump located a mere 11 feet (as the wire flies) from the breaker panel. It shows that AWG 12 or SAE 10 would be required even for this relatively modest load.

By comparison, you are suggesting upping the current flow by a factor of at least five compared to this example, yet keeping the same-size (or one-size-larger if you meant AWG 10) wire, and doing so over what would (given the bow thruster context of this thread) presumably be a significantly longer run.

I don't think so!


If you are going to run cables heavy enough to run the thruster you don't need batteries adjacent to it and you are going to get poor performance due to voltage drop in the cables even after spending $500 on them.
This is sort of a circular and self-defeating statement.

If the cables are indeed "heavy enough", then by definition you WON'T "get poor performance". But what exactly constitutes "heavy enough" (and how much that might cost) will depend entirely on the details of the specific application. The most you can accurately say is that:

-- The larger the load, the heavier the cables must be for any given-length run.

-- The longer the cables between the load and the battery, the heavier those cables must be to support any given-sized load.


The charging line will NOT overheat. The Combiner100 will limit the current flowing from the starting battery to the thruster battery to a safe level.
Here we go AGAIN.



Itteldoo is offline  
Old 09-20-2012, 11:42 AM
  #17  
Senior Member
 
Join Date: Aug 2012
Posts: 2,418
Default

Originally Posted by jethro1 View Post
It is perfectly good information.
Not really. As shown above (and elsewhere in this forum), "yandina"'s apparent technical expertise is sorely lacking. Either that, or he is exceptionally sloppy about presenting that "information", to the point of diluting its value well past nil.


Why should it not be provided?
Because his posts (at least those I've seen lately) are consistently NOT about providing information. They're about promoting his product, even when it is obviously NOT appropriate.


If a vendor has some good information should he not be sharing it?
Sure. But he problem here is that it is NOT "good information".


I imagine that the guy looking for the help will be appreciative,
Only up to the point he discovers that he was led astray, possibly disastrously so.



Itteldoo is offline  
Old 09-20-2012, 11:42 AM
  #18  
Senior Member
 
Join Date: Aug 2011
Location: CT
Posts: 1,155
Default

Just install an extra flux capacitor and call it a day.
Bowens911 is offline  
Old 09-20-2012, 11:47 AM
  #19  
Senior Member
 
Join Date: Aug 2012
Posts: 2,418
Default

Originally Posted by jethro1 View Post
Why are you shouting at us?
Because, when someone suggests doing something as ill-conceived and potentially VERY dangerous as in "denny-o"'s misguided post that I was reacting to, it deserves the strongest possible debunking. People's LIVES could depend on it.



Itteldoo is offline  
Old 09-20-2012, 04:20 PM
  #20  
Senior Member
 
Join Date: Jan 2007
Location: See screen name
Posts: 5,245
Default

Yandina was a "he", but has been a "she" for a few years now. Still has some interesting ideas, but not gospel, products do have a good rep. Should be a sponsor, not spammer here though.
caltexflanc is offline  

Thread Tools
Search this Thread