Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 27-02-2008, 21:58   #46
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
Quote:
it says *not* to ground the device's output. Wheels, the only ground the device has is for your AC ground, not DC.
What are you calling ground. Be very clear here.
Follow this step by step.
1: The -DC output of the charger will go to the Shunt.
2: The same terminal the -DC cable is connected to, will then have another cable (same gauge) going to the block of the engine and the most common connection point is on the bolt that bolts the starter motor to the engine.
3: The alternator will be an isolated case and so the -DC terminal of the alternator will also connect to the block at that same point.
4: The -DC feed to your DC electrical panel -DC Bussbar will also connect to that same terminal on the shunt.
5: The chassis of the charger has a terminal for a cable to connect the chassis to the same Terminal on the Shunt. You will now have several terminals on that one shunt "backbone".
6: The other side of the shunt will have one heavey gauge cable running to the Neg. of the battery bank.
7. The engine start battery Neg. is also connected to that shunt. If you had a dual link system, that Neg would be on the tail side of the shunt so as it can be monitored. But in this case, it can connect at the main side with the other cables.
This setup makes a "star" with the shunt being the centre of it all. Everything stars out from that central point.
__________________

__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 27-02-2008, 22:27   #47
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
Quote:
but we don't put the battery negative on the engine of a boat because it needs to be grounded. (
No that is not the total story. The engine is connected to the gearbox and the gearbox is connected to the propshaft and the propshaft is connected to the propellor and the propellor is connected to the water and the water connects many other connective parts with all that stuff and so you get stray voltages running around. Because you can set up "earth loops" of stray currents, you try and remove as many "looped" paths as possible. So have a single common point to connect all points to is essential. The Alt. and starter being also connected to the point.
__________________

__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 28-02-2008, 07:27   #48
cruiser

Join Date: Nov 2004
Posts: 4,525
Quote:
Originally Posted by Fishspearit View Post
Don't get wrapped up in thinking that you need to 'ground' your 12V system, you don't. We 'ground' a car's negative to the chassis, and we ground our house AC, but we don't put the battery negative on the engine of a boat because it needs to be grounded. (I'm sure somebody will argue with me over this.) The ONLY reason to tie the negative to the engine is for the starter, and the alternator, and the engine electrical parts. Otherwise a floating 12V system is perfectly fine. If you don't want to charge your house bank with the alternator, or start the engine with the house bank, you can let it float. But if you want to do either of those things then you need to put your house negative on an engine. And make sure that you have a battery cable grounding the two engines together. This is an ABYC standard because if you lose the engines negative battery connection, it will try and draw current through the fuel line, so the engine to engine crossover cable is a safety feature.
It's so much easier when working with 12V to think only in terms of positive and negative. Forget about 'ground'.
As an example, a submarine is completely ungrounded, both the AC and DC systems.
Thanks! This is very good advice, I think.

I do plan to add a negative from the house bank to the engine at some point so that I can charge from the alternators. But... I want to take my time and clearly think through that before doing so, so that I don't blow up the alternator diodes by doing something stupid.

For now, I'll just leave the house bank floating and charging off of solar and wind.

This morning, I woke up to 12.7VDC with all normal house loads on last night. There was a little bit of wind, so there was the wind generator charging. Today, I'm running 100% off solar, which is certainly more than keeping up the batteries.

LESSON TO BE LEARNED:

If your electrical system is doing things that don't make sense, take the easy route and buy a new battery bank (if the hydrometer shows it's dead).

All of my headaches could have been avoided by not over-thinking this one. The batteries caused all of the weird voltages and symptoms (except that my house negative floats). All other symptoms were caused by the dead bank.

Today, I am running at peak power with full batteries and I haven't been plugged into the dock for about 18 hours. All systems are on, I'm emailing from the new batteries, used the electric head a couple times, used lights last night, and had the freezer and refrigerator running. All is well. The 6 new Trojan batts really did the trick. 600AH. Nice!

Thanks to those that participated.

I will be following up on this post in a few weeks or so with results from my alternator/house battery charging issues. For now, I have refrigeration, which was my major goal posting this thread. Need to eat and all that... ha ha
__________________
ssullivan is offline   Reply With Quote
Old 28-02-2008, 07:28   #49
cruiser

Join Date: Nov 2004
Posts: 4,525
Quote:
Originally Posted by Alan Wheeler View Post
No that is not the total story. The engine is connected to the gearbox and the gearbox is connected to the propshaft and the propshaft is connected to the propellor and the propellor is connected to the water and the water connects many other connective parts with all that stuff and so you get stray voltages running around. Because you can set up "earth loops" of stray currents, you try and remove as many "looped" paths as possible. So have a single common point to connect all points to is essential. The Alt. and starter being also connected to the point.
So as I suspected many moons ago, is that what ate my props?
__________________
ssullivan is offline   Reply With Quote
Old 28-02-2008, 08:46   #50
Registered User
 
sluissa's Avatar

Join Date: Mar 2006
Location: Pensacola, FL, US
Boat: Westfield UK Kingfisher 20+ - Rabbit
Posts: 402
Images: 4
Send a message via AIM to sluissa
600 AH... I felt a slight twinge of envy.
__________________
sluissa is offline   Reply With Quote
Old 28-02-2008, 11:55   #51
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
Quote:
So as I suspected many moons ago, is that what ate my props?
Hopefully not. Because if it was electrical enough for that to happen, you will have many other more serious issues than just the props. Plus with saildrives, the props themselves are often isolated anyway. I would suggest they have been anti-fouled.
However, it would still be wise to haul at some point in the not to distant future to check things out. You are going to have to to replace the blades anyway.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 28-02-2008, 12:33   #52
cruiser

Join Date: Nov 2004
Posts: 4,525
Quote:
Originally Posted by Alan Wheeler View Post
Hopefully not. Because if it was electrical enough for that to happen, you will have many other more serious issues than just the props. Plus with saildrives, the props themselves are often isolated anyway. I would suggest they have been anti-fouled.
However, it would still be wise to haul at some point in the not to distant future to check things out. You are going to have to to replace the blades anyway.
Agreed. When I get up north, where we have tides, I'll do a little beaching to see if anything got worse.

Also, there is only 1 zinc on my saildrives right now. There were no others in stock when the boat was hauled out for survey. So... I'll have to put that on at the next "beaching" as well.

Thanks for the input. It was very helpful.
__________________
ssullivan is offline   Reply With Quote
Old 28-02-2008, 15:30   #53
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
Quote:
Originally Posted by sluissa View Post
600 AH... I felt a slight twinge of envy.
Thanks Sean (sigh of envy as well), now I have to figure a way to hide this thread from my admiral .... gggggrrrrrrr
__________________
Tropic Cat is offline   Reply With Quote
Old 28-02-2008, 17:55   #54
cruiser

Join Date: Nov 2004
Posts: 4,525
Sorry... just replaced the old batteries with new of similar size, but FAR better brand. "TROJAN MAN!"

I think using wind and solar you need a lot larger battery bank since you can't control when they will be topped off. You could go DAYS without wind or sun.

420AH was more than enough for me with a genset. Now, I find myself hoping for bright sunny days and 20MPH winds all day long. Come to think of it... hey... that's pretty good sailing weather too.


But... envy guys remember... this is my house. Your "shore power" coming from FPL is probably a little beefier than my little 600AH bank. ha ha
__________________
ssullivan is offline   Reply With Quote
Old 29-02-2008, 11:30   #55
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,022
"I think using wind and solar you need a lot larger battery bank since you can't control when they will be topped off. You could go DAYS without wind or sun. "
bear in mind, sully, that you can always put a metal panel box on the wall, and inside that box install an A/B switch that allows the house bank to be connected EITHER to the alternator, or the eco-chargers. One or the other, not both, so you still have the option of running the engine for a few hours to charge the big bank.

Cheap, simple, safe...just put a note & lock/safety or something on the box so no one can throw the switch while the engine is running.<G>
__________________
hellosailor is offline   Reply With Quote
Old 29-02-2008, 12:11   #56
cruiser

Join Date: Nov 2004
Posts: 4,525
Quote:
Originally Posted by hellosailor View Post
"I think using wind and solar you need a lot larger battery bank since you can't control when they will be topped off. You could go DAYS without wind or sun. "
bear in mind, sully, that you can always put a metal panel box on the wall, and inside that box install an A/B switch that allows the house bank to be connected EITHER to the alternator, or the eco-chargers. One or the other, not both, so you still have the option of running the engine for a few hours to charge the big bank.

Cheap, simple, safe...just put a note & lock/safety or something on the box so no one can throw the switch while the engine is running.<G>
This is a good point... but UH OH! Did I do something wrong?

I ask because today I tied the negative of the house battery bank to the engine block so I could charge the house batteries from the alternators, as well as the starting batteries (which are already tied to the block).

I fired up the engines, and saw good charging voltages.

I have bright sun today for solar panels, again good charging voltages.

For a moment, the sun was behind clouds and I had a gust of wind. Again, good charging voltages from the Air-X.

All these devices (solar charge controller, Air-X internal regulation, Xantrex shore power charger, and Yanmar alternators) won't blow each other up, right?

Because so far, when I ran the engines, I got good charging from the alternators and the solar and wind devices are still working.

The way I read your post above, I would have to watch out what order I have things hooked up in. Did I read that wrong? Can't I have everything hooked up at once?

PS: I do isolate the starting batteries from the house with an isolation switch *after* the engine is shut off. But... that shouldn't matter for my alternators, since they either see the starting batteries, or the starting batteries in parallel with the house bank.
__________________
ssullivan is offline   Reply With Quote
Old 29-02-2008, 12:51   #57
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
Yes all charging devices can be connected at the same time. The only thing that can happen is that one of those devices may think that the battery is charged and go into a float mode (if it is amulti-stage regulator like your xantrex), but that is no problem. That device simply won't be adding to the charge.
As long as the alternator is connected to a battery at all times and I presume that the Alt. is connected to the start permanently, it doesn't matter if you switch the house in or out with the engine running. It DOES matter if you have the Start and house connected via switch so as you can select 1/2/both. Then it can be bad for the Alt. Unless you have a field isolator terminal on the switch and it is connected up to the field. But lets not go there, it makes the entire issue more complex than what we are trying to sort at the mo.

However I have one concerning question. Do I remember you saying you have Gel batteries for start??? You can not have two dissimilar batteries on controlled multi-stage chargers. The voltages are too different between Gel and FLA.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 29-02-2008, 12:58   #58
Registered User

Join Date: Apr 2006
Posts: 4,413
Sully,

The problem with multiple charging sources is that anyone of them can lift the "apparent voltage" of the system up and fool the other "regulated sources" that everything is peachy keen.

So for example, if you have some solar cells and they are putting out something in the 14+ v when you fire up the engine, the smart regulator has no idea of the state of your batts, because it measures the system voltage which will be reading as much as 14+ v.

The optimal approach is to manually control which sources are charging and how much since I don't know that there is a smart charge manager which deals with multiple sources at the same time.

The alternator will kick out the most amps, but it needs to see a weak battery to really kick out the amps. As the batt goes full its resistance to more amps in goes up and the alternator will drop down to float.

What you need to do is get your "healthy" batts topped up and let the eco charges maintain them for normal drains. If you have large constant type load - a refer, they will probably not keep up. Then you need to cut them off and let the alternator do some heavy lifting.

I typically run the engine once a day for this purpose and to create hot water. I try to combine this with motoring out of the harbor until sails are set and we can sail.

The other approach is to use an "echo" charge which charges the Start bank. All charging sources are wired to the house bank and so there is no batt selector switch. Start is for the engine start and House does everything else. For emergency a combine switch allows you to get all the batts in parallel so you can start the engine from the house bank.
__________________
Sandero is offline   Reply With Quote
Old 29-02-2008, 13:34   #59
cruiser

Join Date: Nov 2004
Posts: 4,525
Ahhhh! It all makes sense after reading your posts, Wheels and DefJef.

Thank you very much. I have little experience with so many charging sources at once. Glad to see everything will be ok.

I do have gel starting batts and traditional wet lead batts for the house bank. Good point about the different charging values for them. I will fine tune the system as I go.

At the moment, solar and wind seem to be keeping up well. I am at 12.7VDC under full load of the refer and this computer being used through the inverter.

Soon (maybe when the wife comes down), I'll pull the Link 10 out of the land boat and hook it up in here. Otherwise, I'll do that when I get back up North. I can tell the batteries are getting a good charge with solar/wind only since over the past couple nights, I have been seeing just under 13VDC going to bed at night and the same upon waking up - this with no loads or chargers going. Based on all my experience, this shows a pretty well charged battery.

In fact, the refer only uses 10A per hour when running in max power mode. It runs infrequenly now that it is cooled down, and also runs on a slower setting that uses 7A per hour (when running).

All in all, I think the system is good on here now that I can charge from the engines too. The wind and solar are indeed keeping up with the refer, lights, pumps and computer. I just like to know that I can get some "free" power when motoring if there is no sun or wind. Now I can.\

I'm sure the Link 10 will help tremendously when trying to figure out if the solar and wind is keeping up or if I need to run the engines.
__________________
ssullivan is offline   Reply With Quote
Old 01-03-2008, 00:38   #60
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
To make my system a little less complicated, I connected the start bank to my solar panel. Now OK, I don't have the power you have. I only have 20W. So dedicating that to the start bank works well at keeping the AGMs topped off. When they are knocked down by the engine starting, they are very quickly pulled back up by the alternator. The Alternator goes through a charge splitter to the start bank and house bank. This is so the house can alos get a charge from the main engine if we are motoring or motorsailing. The Heart Interface Charger/Invertor charges the house bank only via either the genset or shore power.
Depending what size panels and how many you have, you could perhaps dedicate just one panel with small regulator to your start bank to do the same thing. Alt. charges the bank when dropped via engine starting and the solar panel keeps the bank topped off. All the other panels, Genny and charger/invt can take care of the house duties. Just a thought.
__________________

__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Reply

Tags
battery

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
Could this be the problem? zackc Engines and Propulsion Systems 9 08-02-2008 19:20
Battery Charger Problem cburger Electrical: Batteries, Generators & Solar 10 26-01-2008 06:57
Serious problem bottleinamessage Electrical: Batteries, Generators & Solar 19 26-08-2007 11:39
Battery charger to replace battery? lilly Electrical: Batteries, Generators & Solar 5 22-07-2006 19:11



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:28.


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.