Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 15-10-2007, 12:57   #16
Senior Cruiser
 
rebel heart's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Posts: 6,190
Images: 3
Three cheers for a manual windlass!
__________________

__________________
rebel heart is offline   Reply With Quote
Old 15-10-2007, 14:27   #17
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,596
Images: 240
Three cheers for my manual windlass - Maggie
__________________

__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 16-10-2007, 10:25   #18
Registered User

Join Date: Sep 2007
Posts: 125
Yes, I got stuck with a broken windlass on a charter, they should all have maunal cranks somehow or another.

But, I can't understand why some say a third of the house batteries are not located forward, they could be evenly balanced (with the batteries in the rear), a small breaker panel would allow for the low amp use and trickle charge from the rear ones.

Ane the windlass would work like a damn without the engine on.
__________________
jscott is offline   Reply With Quote
Old 16-10-2007, 18:01   #19
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,056
"But, I can't understand why some say a third of the house batteries are not located forward, they could be evenly balanced (with the batteries in the rear), a small breaker panel would allow for the low amp use and trickle charge from the rear ones."
Old discussion and you'll probably be able to find answers posted on older threads.

Weight forward is simply bad. Batteries forward are either going to suffer a huge coltage drop in the cables--or, cost a fortune to run the right gauge cables forward.

Bottom line, MONEY and PERFORMANCE.

It can be done but most folks aren't willing to make the compromises, or spend the money.
__________________
hellosailor is offline   Reply With Quote
Old 16-10-2007, 18:57   #20
Registered User

Join Date: Apr 2003
Location: Winters - Out Cruising / Summers in the NC mountains
Boat: Brewer 42
Posts: 292
Images: 2
Quote:
Originally Posted by hellosailor View Post
Weight forward is simply bad. Batteries forward are either going to suffer a huge coltage drop in the cables--or, cost a fortune to run the right gauge cables forward.
I must respectfully disagree. We have our windlass battery under our v-berth and our arrangement works just fine.

Weight forward - depends on the boats displacement. We displace 16 tons and the weight forward is irrelavent.

Heavy cable needed - If the windlass was pulling from the house bank, we would need a huge cable run from the house to the windlass. Actually, smaller cables can be used than if the batt is forward. The only large cable is from under the v-verth to the windlass, about 5 feet. From our battery combiner, we run a #8 for charging and have never had a charging problem. The windlass is used so infrequently, it is always fully charged between uses.

I have no idea why anyone in a larger boat would have any other arrangement.
__________________
rleslie is offline   Reply With Quote
Old 16-10-2007, 19:21   #21
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,056
hLeslie-
In your situation it may work, but that is simply because "other things" are swamping out the basic physics. If you displace 16 tons, an extra 80# battery forward may not push your bow down much--but it still pushes it down, still porposies the boat, still has some measureable effect. That may be TOLERABLE and ACCEPTABLE for you--but it still is there and still slows your progress in a sea.

Similarly, there are only two ways to charge that forward battery. You can run something like 00-AWG battery cable and charge it quickly (what is that, about $4 per foot for some 150 feet combined run?) or you can rrecharge it with something dinky like 8g-SAE welding cable--if you don't mind taking an extra hour to recharge it. Either way, you pay for the priviledge and the charging losses. It may be acceptable and practical for you--but you are still paying for it.

Considering that something like 3-4% of pleasure craft in the US (and world) are over 36' in length and less than 3000? 4000? of them are sold in year, that's a minority market. (By all means, do correct these rough numbers.)

There are many ways to skin a cat and you've got one that works well enough for you. Me, I think I'd rather run expensive cables forward and keep that "winch" battery at the base of the mast, centering the extra mass from it. Or perhaps even keeping it secured right under the overhead--so it could also provide MAYDAY transmit power, right until the decks were submerged. (OF course, AGM would allow that to be back in the bilge.[g])
__________________
hellosailor is offline   Reply With Quote
Old 16-10-2007, 20:06   #22
Registered User

Join Date: Apr 2003
Location: Winters - Out Cruising / Summers in the NC mountains
Boat: Brewer 42
Posts: 292
Images: 2
hellosailor

For lighter boats, your analysis is correct. However, on heavy displacement boats the effect of an extra #80 forward is not measurable nor does it slow you at sea.

Windlasses pull heavy loads.....fast. I don't see how locating them aft/centered eliminates large cables. If the batt is aft or centered, you must run a heavy cable for the operation of the windlass.....correct?

We've used #8 for charging during 12 months of cruising and we always have full batts after routine charging from two 120w solar panels and running our Honda 2000 for an hour every third day.

Admittedly, there is one weak point to our setup. If we ever need to pull from the other banks, via the combiner, the #8 will not allow a large fast draw.
__________________
rleslie is offline   Reply With Quote
Old 17-10-2007, 05:17   #23
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,596
Images: 240
Quote:
Originally Posted by rleslie View Post
... We've used #8 for charging during 12 months of cruising and we always have full batts after routine charging from two 120w solar panels and running our Honda 2000 for an hour every third day.
Admittedly, there is one weak point to our setup. If we ever need to pull from the other banks, via the combiner, the #8 will not allow a large fast draw.
Assuming an allowable Voltage Drop of 3%:
#8AWG cable is adequate for about 7.5 Amps over a round-trip cable length of about 60 feet (30' each pos + neg cable).
A 100 Amp load would require 4/0 Cables to maintain a 3% VD over these same 60 Ft. Of cable.

More info' Goto:
http://www.cruisersforum.com/gallery...=500&userid=79
And:
http://www.cruisersforum.com/gallery...=500&userid=79
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 17-10-2007, 07:57   #24
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,056
rl-
In addition to what gordon hints at...Where you locate the windlass battery (not the windlass so nuch as the battery) you may be able to get away with putting the battery 2/3 of the way in between the charger and the windlass. That would allow you to run 00 cable to the battery, and run lighter cable forward to the windlass--because the lighter cable might be good enough for that much shorter run.

The choice of cable size/capacity has as much to do with the round trip (both wires) length of the run it is making, as it does with the current you expect to carry on it. If your cabling is undersized, you will get problems from heat (the cable could overheat and catch fire, especially if not in free air space) or the windlass might be silently overheating (working on lower than optimal voltage) and burn out in 5-10 years instead of 20.

A voltmeter and tape measure can take the "maybe" out of most of that.

Or, what you have might be perfectly good for you. What I'm suggesting--and what I believe Gord is also saying--is that for MOST privately owned sailboats, these problems that we are suggesting DO apply and ARE significant. You are obviously on a larger craft--where sometimes things are done in a better manner.
__________________
hellosailor is offline   Reply With Quote
Old 17-10-2007, 09:02   #25
Registered User

Join Date: Sep 2007
Posts: 125
Hello sailor, you don't get it yet.

Firstly the balance of the boat is critical, not weight forward or weight aft. That means retrofitting a system such as this maybe difficult but not impossible, but at the design stage is dead easy.

Secondly, you TRICKLE charge the forward battery, run 14 ga for 15 amps or even 16 ga. Then run the large windlass wires the last 5 to 6 feet.

If you dead the front battery becasue it is too small then the trickle charge breaker would fire and protect the system. That's okay just wait a bit the battery will rebound and try the breaker again. If that doesn't work a current limiting resistor can be cut in to the circuit, or the battery hauled aft.

To trickle charge you connect the two battery banks togeather. Since in the absence of any significant loads the batterys are equalized and almost no current will flow, one bank may be 12.7 V and the other drawn down to 12.4 V @.003 ohms/foot and say 50 feet that is 0.15 ohms at .3 volts that is 2 amps.

Lets say worst case we have 14.5 V on the house bank and 9.5 V on the windlass, then we have 33.5 amps on 14 guage @ 33 amps we want half of that so install a .25 ohm 100 watt resisitor in the circuit (tiny), now you have 5V/(.25+.15) = 12.5 amps (okay) at trickle charge you get .3/.4 .75 amps also okay.

Another way is to install a solar charge controller type device, although why you would spend the money for one I can't see.

NONE of the above will be neccessary with a properly sized battery bank for the windlass.

No one suggested every one do it, but it most certainly has its applications.
__________________
jscott is offline   Reply With Quote
Old 17-10-2007, 09:38   #26
Senior Cruiser
 
S/V Antares's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Annapolis, Bahamas
Boat: 1983 Gulfstar 36
Posts: 1,249
Images: 1
Thanks JScott, Anyone that has pulled 60+ 4/0 cable through a boat will agree with you. I was involved with Bow Thrusters for a few years and it is the same picture. Given that windlass and thrusters are used for only a few min. at most and normally with hours if not days in between use a battery forward and trickle charging is a simple end effective method.

Someone will now chime in with an opinion based on "What if" . One "Keep it simple " beats a pair of "What ifs"
__________________
Will & Muffin
Lucy the dog

"Yes, well.. perhaps some more wine" (Julia Child)
S/V Antares is offline   Reply With Quote
Old 19-10-2007, 08:03   #27
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,596
Images: 240
Quote:
Originally Posted by jscott
... Secondly, you TRICKLE charge the forward battery, run 14 ga for 15 amps or even 16 ga. ...
Assuming a 3% Voltage Drop:
#14AWG Cu wire will carry a 15Amp load a round-trip distance of 6.66 Feet (3.33 Ft each pos + neg).
#16AWG Cu wire will carry a 15Amp load a round-trip distance of 5.0 Feet.

Notwithstanding:

A trickle charge is a continuous constant-current charge at a low rate (about C/300 to C/100), which is used to compensate for self discharge, and maintain the battery in a fully charged condition.

Assuming a 100 A/H battery, this represents a trickle charge current of <1.0 Amp; for which a #16 cable should be electrically* sufficient over a 75 Ft. Round-trip run..

* In order to preserve mechanical integrity, the smallest cable I use is the more robust #14 AWG. (#16 wire is too flimsy)
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 19-10-2007, 08:50   #28
Registered User

Join Date: Sep 2007
Posts: 125
Gord a 3% voltage drop is a "grabber" number used to size wires for normal low voltage service. The calc I demonstrated will result in the system peforming as calculated.

If one was to install a 16 guage wire without a current limiting resistor or a rather long coil of excess wire (not safe due to potential heat build-up); then if the windlass battery was operated too long and the charger started at the house batteries the 16 gu. wire would melt.

The 3% rules are more to ensure good performance from lights and other devices rather than to substutite for good detailed design work.
__________________
jscott is offline   Reply With Quote
Old 19-10-2007, 13:51   #29
Senior Cruiser
 
Alan Wheeler's Avatar

Cruisers Forum Supporter

Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
Images: 102
Actually, Rick discussed this senario sometime back. I spent ages searching for it in the Archives, but have not found it. If I remember correctly, (this is in my own words with my own thrughts trown in) he stated that the charge cables still had to be similar size to the battery up front as they would if the battery was at the back and the cables connected directly to the winch. Did that makes sense?? In other words, I think firstly it was important that the engine was running when winching. that was the first point. Thus the Battery as the load of the winch came on, would draw a considerable amount of current through the charging cables. If the forward battery was connected to the Alternator only, it will draw what the alternator can throw at it. But if it was connected to the rest of the banks, the cables would draw a lot more. If connected to another bank, then the cables needed to be of sufficient size so as the two banks seperated via distance, charged equally. Otherwise, the further away bank will never "look" charged to the charger and the closer banks will over charge. Regulating the charge is therefore essential and either a multi bank charger, with one bank dedicated to the forward battery is essential. Or otherwise, a DC/DC charger specificly designed for remote battery connection is essential. However, unless the charger is of sufficient size, which they are often not, then the voltage level is never maintained for the winch as it can be with a grunty enough Alternator.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 19-10-2007, 14:48   #30
Registered User

Join Date: Sep 2007
Posts: 125
Yes that is the commom view.

If one installs the system I described above the max normal charging current to the winch battery will occur when the alternator is maintaining 14.5 Volts at the aft house battery, and the windlass has drawn the forward battery down to 9.5 volts, this will be 12.5 amps. A 15 amp breaker will protect 14 ga wire so all is good.

A windlass will draw about 70 amps (depends on size of course) and might run for 5 minutes. That is 4.3 amp hours, so say 5 amp hours.

Over the a full day this would be 0.2 amps so the forward battery would fully charge even if the alternator (or other charging system) never started bringing voltage up to 14.5 to 13.3V, which would increase the trickle charge current.


Lets say there is a additional draw on the forward battery bank of 10 amps (lights etc), for 4 hours a day. This is 40 amp hours.

Over a full day this would be 1.66 amps.

I would likely go to 12 ga wire and a larger current limiting resistor.

The trick is as always to design, install and operate the system properly.

The rule of thumb methods work but are not neccessarily the only way.

Of course get a stuck anchor and you will likely have to run the altenator longer to fully recharge the forward battery bank.

There is really a lot more room in the cyctem then is credited above because the charge current will start at 12 amps and taper logarthmically down resulting in a lot more amphours of charge.

I run a solar charger on a cabin to a battery bank and maintain my batteries at about 13.3 V, (varied wrt to temperaature less when colder) the batteries are now 12 years old and have hardly depleted at all, since the are almost never over or under charged.
__________________

__________________
jscott is offline   Reply With Quote
Reply

Thread Tools
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
Starter Worked 6(!!) Times Before Dying - AGAIN! ssullivan Engines and Propulsion Systems 26 08-04-2007 05:56
A Yanmar Starter Thread Charlie Engines and Propulsion Systems 2 28-03-2007 20:22
Toyota on Lithium Deep Cycle Batteries hellosailor Electrical: Batteries, Generators & Solar 4 28-10-2006 15:00
Which engine? Moby Dick Engines and Propulsion Systems 34 03-08-2006 07:32
New Batteries Needed sjs Electrical: Batteries, Generators & Solar 29 20-05-2006 15:19



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 11:42.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.