Charging three battery banks using ACRs? - SailNet Community
 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 13 Old 12-19-2014 Thread Starter
Junior Member
 
Join Date: Dec 2010
Location: Portland, OR
Posts: 2
Thanks: 3
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Charging three battery banks using ACRs?

Hi all,
I have a house bank, starter and windlass battery, all currently connected with isolators and three (!) battery switches.
The PO had the house bank split into 4 banks which I have combined into 1 and my goal is to further simplify my system. The starter and house bank are close and easily wired for charging but the windlass battery is ~25 feet away in the bow, presumably because the PO didn't want to run a heavy cable the length of the boat.
I'm going to use ACRs (I have 2 x 120amp blue seas available) to charge the batteries but am unsure about how to wire up the ACR with the windlass battery, if it's even workable. Or should I ditch the windlass battery and get a looong fat cable to drive it from the house bank?
Grateful for advice/experience,
Colin
Manannan is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 13 Old 12-20-2014
Bill SV Rangatira
 
Bill-Rangatira's Avatar
 
Join Date: Dec 2006
Location: Tsehum Harbour BC Canada
Posts: 391
Thanks: 47
Thanked 17 Times in 15 Posts
Rep Power: 9
 
Send a message via Skype™ to Bill-Rangatira
Re: Charging three battery banks using ACRs?

Quote:
Originally Posted by Manannan View Post
Hi all,
I have a house bank, starter and windlass battery, all currently connected with isolators and three (!) battery switches.
The PO had the house bank split into 4 banks which I have combined into 1 and my goal is to further simplify my system. The starter and house bank are close and easily wired for charging but the windlass battery is ~25 feet away in the bow, presumably because the PO didn't want to run a heavy cable the length of the boat.
I'm going to use ACRs (I have 2 x 120amp blue seas available) to charge the batteries but am unsure about how to wire up the ACR with the windlass battery, if it's even workable. Or should I ditch the windlass battery and get a looong fat cable to drive it from the house bank?
Grateful for advice/experience,
Colin
the windlass bank is a good idea in a few ways
1) distribute the weight better
2) reduce the need for heavy cable to run the serious amperage many big windlasses use

for the remote bank a dc-dc charger would be better to make up for voltage drops on long wire runs
there are many who would be able to answer this better for you
and hopefully this will bump it up to the top of thread list and get some input from them
Bill


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Bill-Rangatira is offline  
Quote Quick Reply Share with Facebook
post #3 of 13 Old 12-21-2014
Full-time Liveaboard
 
CaptainChaos's Avatar
 
Join Date: Oct 2012
Posts: 36
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 0
 
Re: Charging three battery banks using ACRs?

Yes, ACRs will work but are not necessarily the best solution. Since they just automatically connect the banks together, the charge currents are sub-optimal as you'll typically have two mostly charged batteries (starter & windlass) connected to the house bank which actually needs to be charged.

A better solution would be to get two echo or duo chargers (different companies name them differently though they are pretty much the same thing). Then direct all of your charging sources to the house bank and let the echo chargers charge the other batteries.

The echo chargers are also smart chargers but lower current (10-15 amps). But that is usually more than enough to bring the starter or windlass battery back to full charge in a reasonably short time.

Walt

s/v Wanderlust
Passport 545
CaptainChaos is offline  
Quote Quick Reply Share with Facebook
post #4 of 13 Old 12-21-2014
Senior Member
 
Maine Sail's Avatar
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,828
Thanks: 19
Thanked 213 Times in 162 Posts
Rep Power: 16
       
Re: Charging three battery banks using ACRs?

Two ACR's would work but will require a long run of larger than necessary pos & neg wire all the way to the bow.

If using an ACR for a thruster or windlass bank, and the large wire is already in place, like if left over from a diode isolator, I prefer the Blue Sea ML-ACR which is capable of being manually locked in combine mode for more capacity to the bow bank and can also handle 500A..

Perhaps the best solution, if large wire is not already in place, is the Sterling B2B battery to battery charger. This is a unit similar to the Echo or Duo Charger but can independently float the bow bank where neighter the Duo or Echo will do this. It also tolerates damp environments (it's waterproof) and can either boost or drop voltage to a different battery technology in the bow. The 30A unit is usually sufficient and does not shut down, cycle on/off, if asked for more than 30A, which the Duo charger will do...

Sterling Waterproof Battery To Battery Charger

______
-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.



Last edited by Maine Sail; 12-21-2014 at 09:36 AM.
Maine Sail is offline  
Quote Quick Reply Share with Facebook
post #5 of 13 Old 12-21-2014
Senior Member
 
Maine Sail's Avatar
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,828
Thanks: 19
Thanked 213 Times in 162 Posts
Rep Power: 16
       
Re: Charging three battery banks using ACRs?

Quote:
Originally Posted by CaptainChaos View Post
Yes, ACRs will work but are not necessarily the best solution. Since they just automatically connect the banks together, the charge currents are sub-optimal as you'll typically have two mostly charged batteries (starter & windlass) connected to the house bank which actually needs to be charged.
????? Can you explain this in more detail please...

Quote:
Originally Posted by CaptainChaos View Post
A better solution would be to get two echo or duo chargers (different companies name them differently though they are pretty much the same thing). Then direct all of your charging sources to the house bank and let the echo chargers charge the other batteries.
The Echo can work but is a bit on the light side at 15A. If you only need to anchor once then this is fine but if you require multiple resets it can take a while to get your bank back up.

The Duo is a great unit, BUT it can only output up to 30A. If you exceed 30A it shuts down, pauses and tries again. You can wind up in a situation where it can take many hours of short on/off bursts to get the battery bank below the 30A limit until the Duo remains on...

Quote:
Originally Posted by CaptainChaos View Post
The echo chargers are also smart chargers but lower current (10-15 amps). But that is usually more than enough to bring the starter or windlass battery back to full charge in a reasonably short time.
I would be careful calling either of these "smart chargers" they are one way voltage followers. A truly "smart charger" would be able to do a float mode independent of the main bank and neither of these devices can do that. The house bank has to enter float before the Echo or Duo will do so... Is this bad? No, but a house bank can be in bulk/absorption for many hours and the bow bank will get the same voltage, minus a tad bit of voltage drop, until the house bank enters float. The Sterling B2B can float independently of the house bank and won't tap out if the bow bank needs more than 30A...

There are many ways to do bow banks or windlasses and often the easiest, and least complicated, is large cables from the house bank. This results in less "dead lead" on board and more usable lead.. Course if you already have a bow bank, as the OP does, then large cable runs would not be my first choice and a B2B would likely get the nod...

______
-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.



Last edited by Maine Sail; 12-21-2014 at 09:52 AM.
Maine Sail is offline  
Quote Quick Reply Share with Facebook
post #6 of 13 Old 12-21-2014
Senior Member
 
Join Date: Aug 2006
Location: Arlington, VA
Posts: 1,853
Thanks: 0
Thanked 11 Times in 9 Posts
Rep Power: 10
   
Re: Charging three battery banks using ACRs?

Another completely different option is the one I have used on my boat for many years.

I also have a house bank and start battery with an EchoCharge to maintain the start battery. That works just fine....flawless for over a decade.

I also have a windlass battery bank consisting of two golf-cart batteries located under the V-berth in the forward cabin, where it's only a short run to the windlass itself. These batteries are maintained by a dedicated 55A smart battery charger....an Iota DLS-55/IP4.

I have three ways to power this charger: (1) at dockside, from shorepower; (2) an AC generator (NextGen 3.5KW); and (3) an inverter (Victron Multiplus 1500). One or more of these sources is always available.

And, the windlass battery requires very little charging, normally. More than a start battery, to be sure, but much less than the house batteries.

I've found I can anchor multiple times without the need to charge the windlass batteries at all, so for me this system has worked out very well.

It also works very well for my type of sailing wherein I like to come to anchor, and leave the anchorage completely under sail...without need to start the engine.

Bill
Bill-Rangatira likes this.

Last edited by btrayfors; 12-21-2014 at 09:38 PM.
btrayfors is offline  
Quote Quick Reply Share with Facebook
post #7 of 13 Old 12-22-2014
Full-time Liveaboard
 
CaptainChaos's Avatar
 
Join Date: Oct 2012
Posts: 36
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 0
 
Re: Charging three battery banks using ACRs?

Maine Sail, you have to be an engineer.

I always have trouble on these forums because if I get too technical, a lot of people won't understand but if I'm too loose, the engineers pick it apart. I don't want to get into Kirchoff's Laws, etc. so I try to simplify at, possibly, the risk of over-simplifying.

Quote:
Originally Posted by Maine Sail View Post
????? Can you explain this in more detail please...
Some of the problems with ACRs

1) If you have banks of mixed battery types, you must program the charger to comply with the lowest common denominator of charging profiles so AGMs may not be fed as much current as they can take because of a different battery type in another, now connected bank.

2) With different states of charge between banks, there can be some currents flowing between the banks as opposed to the charger feeding all banks.

3) If a battery is fully charged most of the time (starter battery, windlass battery when it hasn't been used in a while, etc.) but the house bank is continually used, the charger will put higher than float voltages to those batteries, as well, possibly causing higher gassing, boiling off the electrolyte...

Quote:
Originally Posted by Maine Sail View Post
The Echo can work but is a bit on the light side at 15A. If you only need to anchor once then this is fine but if you require multiple resets it can take a while to get your bank back up.

The Duo is a great unit, BUT it can only output up to 30A. If you exceed 30A it shuts down, pauses and tries again. You can wind up in a situation where it can take many hours of short on/off bursts to get the battery bank below the 30A limit until the Duo remains on...
I'm a full-time liveaboard and am on the hook 95% of the time so my windlass and starter batteries are typically fully charged but my house bank cycles daily so my solar charge controller is going through the bulk/absorption/float cycle almost every day or if I happen to run my generator (rare), my 120 amp charger will go through the same cycle with higher currents.

I've never had an issue with the 30A limit from the duo charger but I don't use the bow thruster that often and usually only use the windlass to weigh anchor. I use freefall and feather the clutch when setting the anchor.

Quote:
Originally Posted by Maine Sail View Post
I would be careful calling either of these "smart chargers" they are one way voltage followers. A truly "smart charger" would be able to do a float mode independent of the main bank and neither of these devices can do that. The house bank has to enter float before the Echo or Duo will do so... Is this bad? No, but a house bank can be in bulk/absorption for many hours and the bow bank will get the same voltage, minus a tad bit of voltage drop, until the house bank enters float. The Sterling B2B can float independently of the house bank and won't tap out if the bow bank needs more than 30A...
When I use the term "smart" controller, I recognize there are levels of intelligence but, at least the duo-chargers on my boat, can be programmed for the battery type and have some knowledge of charge states to stop charging a fully charged battery or at least reduce the currents to a low enough level to be relatively harmless.

Quote:
Originally Posted by Maine Sail View Post
There are many ways to do bow banks or windlasses and often the easiest, and least complicated, is large cables from the house bank. This results in less "dead lead" on board and more usable lead.. Course if you already have a bow bank, as the OP does, then large cable runs would not be my first choice and a B2B would likely get the nod...
My current boat has a battery under the v-berth for the anchor windlass and bow thruster, the starter batter for the Yanmar and then 4x8D 260AH in the house bank. All batteries are AGM. I have two duo chargers, one between the house bank and the forward battery and a separate one between the house bank and the starter battery.

All of my charging sources are wired into the house bank and the duo chargers then charge the other batteries.

I hope this clarifies what I was trying to say...

Cheers,
Walt

Walt

s/v Wanderlust
Passport 545
CaptainChaos is offline  
Quote Quick Reply Share with Facebook
post #8 of 13 Old 12-22-2014
Senior Member
 
Maine Sail's Avatar
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,828
Thanks: 19
Thanked 213 Times in 162 Posts
Rep Power: 16
       
Re: Charging three battery banks using ACRs?

Quote:
Originally Posted by CaptainChaos View Post



Some of the problems with ACRs

1) If you have banks of mixed battery types, you must program the charger to comply with the lowest common denominator of charging profiles so AGMs may not be fed as much current as they can take because of a different battery type in another, now connected bank.
Only if the charge voltages are different. The same can be said of any battery charger with two or three outputs or an alternator or inverter charger or solar controller.. With mixed banks that have varying voltages eg: GEL (14.1V) and Trojan (14.8V) or GEL and Odyssey (14.7V) or GEL and Lifeline (14.4V) then you need a way to either boost or drop the voltage to the other bank..



Quote:
Originally Posted by CaptainChaos View Post
2) With different states of charge between banks, there can be some currents flowing between the banks as opposed to the charger feeding all banks.
Once you have voltage parity current simply flows where it is needed. Both banks will be in absorption for the same amount of time. I have solar charged banks that are world cruised and charged via ACR's or Combiners. Some of these starting banks are 10+ years old with over 30,000+ hours of solar charging. In not one case have I seen a start battery "over charged" or fail before the house bank but internet lore will have you belive that an ACR will "cook" a start battery. Never once seen it.....

Quote:
Originally Posted by CaptainChaos View Post
3) If a battery is fully charged most of the time (starter battery, windlass battery when it hasn't been used in a while, etc.) but the house bank is continually used, the charger will put higher than float voltages to those batteries, as well, possibly causing higher gassing, boiling off the electrolyte...
This internet lore continues and all I can say is it does not happen in the real world... However, seeing as you make that point a Duo or Echo will provide the same voltage to a second bank that the house battery is getting so in reality there is no realistic difference.

Duo's and Echo's DO NOT stop charging or independently float from the house bank. This is very often misunderstood. They simply follow the voltage of the house bank. The Echo limits max output voltage to 14.4V and the Duo's max voltage is user adjustable but neither will drop voltage to float level unless the house bank goes their first. They get the same duration of absorption voltage that the house bank gets because they are voltage followers..These two devices are often grossly misunderstood about how they actually operate. In full disclosure I am a dealer for Balmar, and really do like the Duo, for the right application.


Quote:
Originally Posted by CaptainChaos View Post
When I use the term "smart" controller, I recognize there are levels of intelligence but, at least the duo-chargers on my boat, can be programmed for the battery type and have some knowledge of charge states to stop charging a fully charged battery or at least reduce the currents to a low enough level to be relatively harmless.
Neither the Duo Charger or Echo Charger stop charging when a bank is full. Many misunderstand this because the manuals and marketing can be a bit misleading. The Duo can be programmed for max voltage, battery type voltage and different turn on voltage but otherwise it simply follows the voltage & charging stage of the house bank. The drop in current is dictated by the battery at % SOC & XX.XX voltage and not the Duo Charger. The same occurs with an ACR. At X volts and X% of charge a battery can only take what it can take and you either need to raise or drop voltage to change accepted current.

In a battery over temp situation the Duo simply ceases operation because it can't independently drop voltage to a lower level like an alternator regulator or battery charger or solar controller can.. Once the battery cools it simply resumes.

Things like this were added to the Duo Charge manual at the request of marine electricians, such as myself, so that folks can make good decisions on how and where to use them:

Balmar:

"The maximum output amperage of the Duo Charge is 30 amps. When used as a stand alone charge source, the Duo Charge is designed to discontinue charging when demands exceed its capabilities. At that point, the Duo Charge will wait for a short period and query if the demand has diminished to below its 30-amp capacity. If so, the Duo Charge will continue charging. If demand continues to exceed capacity, the Duo Charge will continue to shut down, while checking periodically to see if demand has diminished. So, if you decided to install the Duo Charge to charge a bow thruster battery, windlass battery or a battery that can be highly discharged the Duo Charge may go into the over current condition because the demand is greater than 30 amps."


Guys like myself have been bugging Balmar for years to fix this issue but now that they have been sold I don't see this ever happening..

Many boat owners don't even know this may be occurring and get saved by solar or wind. If you don't have 30A+ of input current the Duo can't shut down on over-demand by exceeding 30A on the output.. It is situations where owners only charge via dock or alternator where a solenoid drive is necessary. If you have solar you may never notice the Duo cutting in and out because if input current from solar is not in excess of 30A this will not occur...

The Duo's and Echo's are great devices, I install tons of them, but now that Sterling has the B2B's out they are an arguably better choice for a bow bank because they can both boost, drop and do float independently as well as not time out on over current.. My one complaint with these is no battery temp sensor, and the Duo wins here. There is no one perfect battery to battery charger but the Duo's Echo's and Sterling B2B's are all great if appropriately chosen for the application. ACR's / Combiners are also great devices and perhaps one of the most reliable products in the marine environments.

Again, many ways to skin a cat, I just want people to have as much info as they can to make the right decision for their application..

______
-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.



Last edited by Maine Sail; 12-23-2014 at 03:41 PM.
Maine Sail is offline  
Quote Quick Reply Share with Facebook
post #9 of 13 Old 12-22-2014
Senior Member
 
Stu Jackson's Avatar
 
Join Date: Jul 2001
Posts: 871
Thanks: 0
Thanked 12 Times in 11 Posts
Rep Power: 14
 
Re: Charging three battery banks using ACRs?

Quote:
Originally Posted by CaptainChaos View Post

Some of the problems with ACRs

1) If you have banks of mixed battery types, you must program the charger to comply with the lowest common denominator of charging profiles so AGMs may not be fed as much current as they can take because of a different battery type in another, now connected bank.

2) With different states of charge between banks, there can be some currents flowing between the banks as opposed to the charger feeding all banks.

3) If a battery is fully charged most of the time (starter battery, windlass battery when it hasn't been used in a while, etc.) but the house bank is continually used, the charger will put higher than float voltages to those batteries, as well, possibly causing higher gassing, boiling off the electrolyte...
Walt, Maine Sail and I had this discussion many, many moons ago. Simply an urban myth, especially #3.

I know he's tired of retyping the answer, so I saved this, since it comes up so often:

Overcharging with Combiners or ACRs The MYTH:
Overcharging Batteries with a Combiner or ACR

Stu Jackson, C34, 1986, M25 engine, Rocna 10 (22#)
Stu Jackson is offline  
Quote Quick Reply Share with Facebook
post #10 of 13 Old 12-22-2014
Full-time Liveaboard
 
CaptainChaos's Avatar
 
Join Date: Oct 2012
Posts: 36
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 0
 
Re: Charging three battery banks using ACRs?

Quote:
Once you have voltage parody current simply flows where it is needed.
I agree with your statement about after you have voltage parity. I'm more concerned with the case where there isn't parity, yet, and you have a deeply discharged bank and a fully charged bank.

The only thing I can think of in the real world that may mediate this action is the ACR's voltage sense may not close the relay until a deeply discharged bank has been brought back to 13.2V which means a large part of the bulk cycle may be completed and the voltage of the other bank will be below the 13.2V and therefore will be charged also when the relay closes.

Quote:
Duo's and Echo's DO NOT stop charging or independently float from the house bank. This is very often misunderstood. They simply follow the voltage of the house bank.
I suspected this of the echo charger but wasn't sure. However, I'm surprised the Duo Charger is a simple voltage follower as I was led to believe it used essentially the same 3 stage charging algorithm as the 'smart' voltage regulator for their high output alternators.

Quote:
Many boat owners don't even know this may be occurring and get saved by solar or wind. If you don't have 30A+ of input current the Duo can't shut down on over-demand by exceeding 30A on the output..
I suspect in my case, I just don't use the bow thruster or windlass enough to discharge the battery enough that 30A doesn't bring it back up quickly. In addition, I usually have the diesel on because I'm weighing anchor so my Balmar alternator is providing some power through the duo charger when I'm using the windlass so the battery doesn't get as deeply discharged as one might think.

Good discussion! It's always good to think things through to really understand them.

Walt

s/v Wanderlust
Passport 545
CaptainChaos is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
(slightly O/T) charging multiple battery banks with solar rmeador Electrical Systems 4 10-01-2014 02:47 PM
Battery banks must be the same or can be different? edwmama Electrical Systems 6 11-16-2010 02:39 AM
Battery Banks islands50 Gear & Maintenance 2 04-19-2010 08:52 AM
Battery Chargers for Multiple Battery Banks btrayfors Electrical Systems 5 11-15-2009 11:57 AM
Battery Banks 1 or 2 SimonV Gear & Maintenance 9 10-25-2007 09:25 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome