more battery questions - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Electrical Systems
 Not a Member? 


Like Tree1Likes
Reply
 
LinkBack Thread Tools
  #1  
Old 12-24-2011
Member
 
Join Date: Oct 2009
Posts: 43
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Fitz87 is on a distinguished road
more battery questions

Last year I replaced all of the peripheral wiring and this year I want to replace all of the "big wires" connecting batteries, charger, etc. I have read and learned much from the posts on this site. I have a couple of specific questions and was hoping for some input before I started ordering stuff

1. I'm thinking of using the Blues Sea "Add a Battery" product that includes an ACR and a on-off-combine switch. Anyone have thoughts on this product or something else I should consider?

2. All the diagrams posted here and in the Blue Sea info show the ACR wired back to the bats (or + bus bars). In a picture on Blue Sea it shows the ACR wired directly to the switch. It would save me a couple of pretty long runs of pretty big wire to connect the ACR to the switch, but I'm not sure this is right, or even OK. Am I correct in thinking The ACR should be wired back to the batteries (or +bus bars)?

3. Is there a way to figure out how much current the starter (18hp universal) actually draws? Is this information on the starter somewhere? How about the glow plug?

Thanks,

Fitz
Reply With Quote Share with Facebook
  #2  
Old 12-24-2011
Senior Member
 
Join Date: Aug 2006
Location: Arlington, VA
Posts: 1,808
Thanks: 0
Thanked 4 Times in 4 Posts
Rep Power: 9
btrayfors will become famous soon enough btrayfors will become famous soon enough
Need to know more about your existing setup before making firm recommendations.

What is your present setup....

House batteries....size, type, configuration?

Start battery, if any?

Present wiring setup....disconnect switch(es)?

Fusing?

Alternator connected to?

Size/type? Externally regulated?

Battery charger connected to?

Solar?

Wind?

The more detailed the info you provide us, the better will be your recommendations.

Happy Holidays,

Bill
Reply With Quote Share with Facebook
  #3  
Old 12-24-2011
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,049
Thanks: 0
Thanked 68 Times in 59 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Tha Blue seas ACR is a great product. The Dual Circuit Plus switch makes a lot less sense though. The issue is the only way it allows you to start from the house bank is if you combine banks. If the start battery is not able to start the engine you are better off to use the house bank by itself. Combining a dead battery with a charged battery is not a good idea. If you have a 1/2/both/off switch keep it as it is a more logical choice. Wire all charge sources to the house bank and with the ACR between the 2 banks the start battery will be charged automatically. The switch becomes one for use and will have nothing to do with charging which will be fully automatic.

To go one step further use the house bank for all loads, engine starting as well as house loads. Keep the "start" battery as an emergency battery. Nothing could be simpler.

Remember to fuse the banks - both. Use ANL fuses sized for the wire ampacity.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #4  
Old 12-24-2011
Maine Sail's Avatar
Senior Member
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,286
Thanks: 10
Thanked 117 Times in 85 Posts
Rep Power: 15
Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice
Quote:
Originally Posted by mitiempo View Post
Tha Blue seas ACR is a great product. The Dual Circuit Plus switch makes a lot less sense though. The issue is the only way it allows you to start from the house bank is if you combine banks. If the start battery is not able to start the engine you are better off to use the house bank by itself. Combining a dead battery with a charged battery is not a good idea. If you have a 1/2/both/off switch keep it as it is a more logical choice. Wire all charge sources to the house bank and with the ACR between the 2 banks the start battery will be charged automatically. The switch becomes one for use and will have nothing to do with charging which will be fully automatic.

To go one step further use the house bank for all loads, engine starting as well as house loads. Keep the "start" battery as an emergency battery. Nothing could be simpler.

Remember to fuse the banks - both. Use ANL fuses sized for the wire ampacity.
I agree. However some folks seem to "want" a dedicated start battery.

I MUCH prefer to do it this way and retain all the features and redundancy of the 1/2/BOTH...



I am also not a big fan of the DCP switch, other than for "simplicity", but you give up a lot of redundancy for that "simplicity".

We use just the 1/2/BOTH on our own boat. It is wired as a "use" switch. I have not been able to record ANY voltage spikes or electronic dropping dips on our system even with an o-scope. I have also measured numerous customers boats with varying engines and not been able to record a spike.

On our boat we have over 3000 cranking amps available at 70F using the house bank. Our "starting battery" about 800 CA. Our five year old, 3 group 31, deep cycle wet cell bank still supports 11.7V during engine cranking. All that and they've been charged for the five years with a dumb regulator, never equalized in the five years and left on-board our boat winters without a charging source other than the occasional visit..
chef2sail likes this.
__________________
______
-Maine Sail / CS-36T


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




© Images In Posts Property of Compass Marine Inc.


Reply With Quote Share with Facebook
  #5  
Old 12-24-2011
Member
 
Join Date: Oct 2009
Posts: 43
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Fitz87 is on a distinguished road
Thanks very much! I have a 1/2/both/off switch and will use that and just get the ACR.

As for my existing system... Thats a very long and somewhat scarry story that is soon to be removed and forgotten!!!

In short, 1 battery bank of 2 group 27s. I believe all hot wires are "bussed" through the starter.

Like I said- soon to be removed!

Thanks again,

Happy Holidays!
Reply With Quote Share with Facebook
  #6  
Old 12-24-2011
Senior Member
 
Join Date: Aug 2006
Location: Arlington, VA
Posts: 1,808
Thanks: 0
Thanked 4 Times in 4 Posts
Rep Power: 9
btrayfors will become famous soon enough btrayfors will become famous soon enough
That's what I was afraid of, and why I asked you for more details.

While I have deep respect for Mainesail and mitiempo, no one can adequately repond to your questions unless they understand: (1) what you have now; and (2) what you are planning.

If, indeed, you only have two group 27s, then IMHO it makes no sense at all to use an ACR. If you're planning to add another battery, like a start battery, and use the two G27's for the house, then it could well be that you'd be better advised to use a simple voltage follower device, like the EchoCharge or DuoCharge, rather than an ACR.

When you have some time, you might provide some more details, including size of boat, type of cruising you do, type of batteries you have/are planning to have (flooded, gels, AGMs), your charging setup (alternator, charger, solar, wind); etc.

The "cookie-cutter" approach only goes so far, and before you get started/guided onto a perilous path it would be good to have a closer look.

Bill
Reply With Quote Share with Facebook
  #7  
Old 12-24-2011
Member
 
Join Date: Oct 2009
Posts: 43
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Fitz87 is on a distinguished road
Sorry for the short reply, I was trying to ignore the wife yelling at me about how late we were going to be for church while I was writing it!

I have an '83 Tartan 3000 that I bought about 4 years ago and adore, but...
a kind way to put it is that I have had many opportunities to learn! I think it was Donald Rumsfeld who made the comment about 'things we know, things we don't know, and things we don't know that we don't know'. I have learned things that I did not even know I didn't know!

I'll try to give some more details:

I have the original Tartan DC panel, which is kind of cool, but not adequate. I just completely rewired all the peripheral circuits through it though, so for now it stays.

I replaced old flooded bats when they died with group 27 deep cycle AGMs about a year ago. The plan has always been to add a starting battery and I am just now getting around to it. The AGMs are currently wired to a 1/2/both/off switch individually. No fuses, no bus bars, just ancient scarry looking wires.

A hot wire goes from the switch to the starter. The alternator is wired directly to the starter. A hot wire goes from the starter to the DC panel. The label for the alternator is in a place that I can't get to easily to see, but it looks about as old as everything else.

There is a nice newer charger with 2 outputs which are currently wired to the AGMs individually. With the new system, I will wire all the charge to one place and use an ACR or alternative to handle it from there.

I'll add a starting battery, probably group 27 size for where I am thinking of puting it. Then I will use the 2 AGMs as the house bank.

The AGMs are located under the starboard settee, about 10 feet from the engine, 15 from the panel. There is not clearance to use terminal fuse blocks but there is room to put a bus bar on one of the sidewalls. This is where I plan to connect the AGM bank, the charger, the alternator, the switch, and the ACR (or alternative).

There is a cubbie about even with the companionway on the port side that's close to the engine where I plan to put the starter battery.

I plan to move the switch to be above the steps in the companionway. The ACR (or alternative (if needed)) will go here too.

I appreciate your responses very much and am open to suggestions.

Thanks again,

Fitz
Reply With Quote Share with Facebook
  #8  
Old 12-24-2011
Senior Member
 
Join Date: Aug 2006
Location: Arlington, VA
Posts: 1,808
Thanks: 0
Thanked 4 Times in 4 Posts
Rep Power: 9
btrayfors will become famous soon enough btrayfors will become famous soon enough
Fitz,

Thanks for the additional details. Now we're getting somewhere :-)

I know about Admirals and Xmas....mine has set some chores for me, too. And, it being Xmas Eve, my head may not be as clear as it could be :-)

If you bear with me, we'll sort this out over the next few days. There are a couple of other items I need to know, but some things are clear from the information already provided.

From what you've described so far, it seems the major concern to be overcome -- and it can be -- is the long run from the house battery bank to the charging sources.

Since you're planning to essentially remove all the old wiring and start anew, that really simplifies things.

I assume you'll want to stick with a group 27 AGM for the start battery. It's generally best to stick with the same type of battery for both the house and the start batteries.

Where are you planning to locate the start battery? Will it be aft near the engine compartment, or forward co-located with the house batteries under the settee, or elsewhere?

For starters, you'll want to treat both group 27 house batteries as a single bank, i.e., run them in parallel.

You'll also want to run all onboard charging sources...the battery charger, the alternator, and any others like solar or wind or diesel generator directly to the house batteries, with appropriate fusing located close to the house batteries. "Appropriate fusing" in your case will mean ANLs, since you don't have room for the MRBF terminal types.

You'll want a healthy sized cable going to the house batteries from the alternator output lug, and another same size cable running from the alternator ground to the house battery ground lug. Sizing of these cables will depend both on the size of your alternator -- present and anticipated -- and the length of the cables.

I believe it would be good in your case to use an EchoCharge device to maintain the start battery. This is a little device which sits between the house batteries and the start batteries and maintains the start battery automatically. Nothing to switch, and nothing to worry about once it's installed correctly. The only tricky part is getting the wire size correct, and that depends on the length of the run. Since the maximum current carried by the EchoCharge is 15A, you don't need a huge cable as you might with a "combiner". The device can be located anywhere it's convenient, generally better outside the engine compartment and outside the battery compartments. I like to put them where you can see them.

You may well want to install a safety fuse in the starter cable as well, even though ABYC doesn't require one. It's a very good idea to have one, properly sized, to avoid a catastrophic fire in the event of a solenoid or starter fault.

We can leave the wiring of the 1-2-Both-Off switch for another time, but I generally like to do something like MaineSail shows in his diagram, i.e., use the #2 position only in an emergency when you need to start the engine from the house batteries. I know Maine likes to use house batteries for starting, but I don't, both because they're not designed for it and because of the possibility of unwanted transients to/from other equipment on the circuit. Much better, IMHO, to keep the start circuit separate, and to use the start battery to start the engine as it's built to do. Of course, with AGMs there's not all that much difference, if any, since they are very capable of putting out a lot of current quickly.

And, if you wire it like Maine's diagram you can do either: (1) keep the start circuit separate, using it's own ON-OFF switch, or (2) keep it really simple by leaving the switch in the BOTH position and starting the engine from the house batteries. For some folks this is easier; Maine thinks some may not be able to handle the concept of a separate ON-OFF switch for the start circuit :-)

AGMs are capable of soaking up a lot of current when charging, easily taking their AH rating in charging amps. Two Group 27s would give you roughly 200AH and it's highly unlikely you'll have anything aboard capable of generating that much current. However, unless you're careful, the AGMs could destroy a small alternator which isn't designed to put out it's maximum power for hours on end. You might tell us what you're thinking/planning re: alternator/regulator situation and upgrades, if any.

Enough for now. It's Christmas Eve.

Very best to you, and to all who follow this Board...

Happy Holidays,

Bill

Last edited by btrayfors; 12-24-2011 at 09:38 PM.
Reply With Quote Share with Facebook
  #9  
Old 12-24-2011
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,049
Thanks: 0
Thanked 68 Times in 59 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Fitz

I am a fan of the Echo Charge in a situation like yours, and I only mentioned the ACR because you already had it in mind. They will both work well, the ACR is less expensive but does need heavier cabling than the Echo so the price is close when all is considered. Battery Chargers | Auxiliary Battery Charger | Xantrex

For fusing your battery banks, and both should be fused, I would use ANL fuses if MRBF fuses won't fit. These should be close to the batteries, 7" suggests ABYC but this isn't always possible.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #10  
Old 12-24-2011
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,049
Thanks: 0
Thanked 68 Times in 59 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Bill

With a 1/2/both switch each bank can be a house bank so I believe both should be fused.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Battery Questions sundog01 Electrical Systems 1 05-18-2009 05:06 PM
Battery questions Popeyensweetp Electrical Systems 4 02-22-2009 11:23 PM
More battery theory questions hertfordnc Gear & Maintenance 1 04-22-2008 08:47 AM
Charging / Battery questions wduncan50 Gear & Maintenance 17 01-16-2008 03:51 PM
More Battery Questions.... Alden68 Gear & Maintenance 26 04-16-2007 06:44 PM


All times are GMT -4. The time now is 10:49 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.