Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-05-2019, 09:52 AM   #1
Senior Member
 
City: Long Beach
Country: CA
Vessel Model: '81 CHB34
Join Date: May 2014
Posts: 106
ACR with alternator and AC charger

I'm going through the endless process of untangling and updating the wiring on my 1981 CHB.

I would like to wire up the alternator with an ACR (automatic charging relay), so anytime the engine is running the alternator charges house + engine bank. However, in doing so the ACR switch will be active when the AC charger is powered, which is about 300 days year.

Is it ok to keep the house and engine banks combined for that much time, with AC charger? The house and engine are sized differently, conventional wet acid chemistry.
__________________
Advertisement

winty is offline   Reply With Quote
Old 01-05-2019, 10:16 AM   #2
Guru
 
djmarchand's Avatar
 
City: Litchfield, Ct/Punta Gorda, Fl
Country: USA
Vessel Model: Atlas Pompano 23- outboard
Join Date: Aug 2012
Posts: 4,416
I have done what you propose for years with no affect on the batteries. It helps that both house and starting batteries share the same chemistry. It really isn't any different than hooking up a shore power charger with two separate outputs to the separate battery systems. Almost all dual output shore power chargers use the same charging algorithm for both outputs.

As long as you are untangling wiring, consider wiring the alternator output to the house bank instead of the starter terminal where it is wired on most engines. The bank that needs the most current routinely- the house bank is the one where the alternator output should preferably be wired to.

David
__________________

djmarchand is online now   Reply With Quote
Old 01-05-2019, 11:02 AM   #3
Guru
 
tiltrider1's Avatar
 
City: Seattle
Country: USA
Vessel Name: AZZURRA
Vessel Model: Ocean Alexander 54
Join Date: Aug 2017
Posts: 1,192
A smart combiner will solve your issue.

https://www.magnum-dimensions.com/sm...ttery-combiner
tiltrider1 is offline   Reply With Quote
Old 01-05-2019, 01:46 PM   #4
Grand Vizier
 
Delfin's Avatar
 
Join Date: Jan 2010
Posts: 3,398
No problem. The charge source couldn't care less how many batteries are in a bank, and when combined, you've just added another battery or two.
__________________
Delfin
"Dad always thought laughter was the best medicine, which I guess is why several of us died of tuberculosis." - Jack Handy
Delfin is offline   Reply With Quote
Old 01-05-2019, 03:23 PM   #5
Guru
 
kchace's Avatar
 
City: Brookline, NH
Country: USA
Vessel Name: Blue Heaven
Vessel Model: Albin 43 classic double cabin, twin 135 Lehmans
Join Date: Sep 2013
Posts: 1,367
Quote:
Originally Posted by winty View Post
I'm going through the endless process of untangling and updating the wiring on my 1981 CHB.

I would like to wire up the alternator with an ACR (automatic charging relay), so anytime the engine is running the alternator charges house + engine bank. However, in doing so the ACR switch will be active when the AC charger is powered, which is about 300 days year.

Is it ok to keep the house and engine banks combined for that much time, with AC charger? The house and engine are sized differently, conventional wet acid chemistry.
Yes, this is completely ok.

Ken
kchace is offline   Reply With Quote
Old 01-05-2019, 03:57 PM   #6
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 11,985
Yes, as mentioned above, this is fine. I like David's advice to wire the alternator to the house bank. I do this and use a switched Yandina 160A combiner to share the charge, when needed, with the start battery. Like you, I have same chemistry batts....FLA.
FlyWright is offline   Reply With Quote
Old 01-05-2019, 06:01 PM   #7
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 3,672
I have a Promariner 60 amp charger hooked to my 2 4D start batteries and to my house bank that is 4 6 volts in series/parallel configuration. I have 2 Blue Seas ACRs that connect each of the 4Ds to the house bank for charging when underway. When I hook up the boat to shore power or generator, I have a on/off switch in the ground wires coming off the ACRs that I turn off which removes the ground reference on the ACRs. It effectively disables the ACRs. When I installed the ACRs I called Blue Seas and asked them how it would be possible to disable the ACRs when on shore power. In looking at the schematics I realized when on shore power the banks would combine as soon as the voltage reached the preset threshold. BS recommended 3 solutions. One was the on/off switch. Two was a 120 volt relay to break the ground when on shore power. Three was to buy their battery charger so that ACRs could be cabled to it and the charger would turn off the ACRs. I went with the switch. I have to remember to turn it off when I plug into shore power or the genset but that isn’t a big deal since I am at the main electrical panel anyway.
Comodave is online now   Reply With Quote
Old 01-05-2019, 07:01 PM   #8
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 11,985
Comodave, I have a similar switch function on the Yandina. It works great for my purposes. When I last left the boat, I didn't know how long I'd be gone....maybe a while, so I left the start batt on the float charge. Went to the boat today after a month away with the batts paralleled. Turned off the switch to stop charging the start batt. Today when I left, knowing I'd be back within a week or two, left the switch off since the start batt is fine without a float for several weeks. I like the flexibility on sharing the charge without the risk of paralleling the loads.

What are you starting with those 2 4Ds? You might be carrying around a lot of dead lead as, IIRC, our illustrious CMS called it. Have you ever considered one G31 start battery and a larger house bank with a couple more GCs?
FlyWright is offline   Reply With Quote
Old 01-05-2019, 08:19 PM   #9
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 3,672
I have twin Lehman SP225s. I know that I could get by with smaller start batteries but the battery boxes are custom made for 4Ds and the house bank isn’t near so I cannot use any of the space to enlarge the house bank.
Comodave is online now   Reply With Quote
Old 01-08-2019, 05:59 AM   #10
TF Site Team
 
Bacchus's Avatar
 
City: Seneca Lake NY
Country: US
Vessel Name: Bacchus
Vessel Model: MS 34 HT Trawler
Join Date: Nov 2014
Posts: 2,578
Wintry
You might want to take a look at what I did and why when redoing my alternator & AC charging scheme.
I looked at Blue Sea ACR but decided on a Sterling CVSR.
Schematics and rationale all can be found at Bacchus website - Projects - page through to find the Charging System Mods
http://dkloeber.wixsite.com/bacchus
__________________
Don
2008 MS 34 HT Trawler
"Bacchus"
Bacchus is online now   Reply With Quote
Old 01-26-2019, 01:40 PM   #11
Veteran Member
 
City: New Orleans
Country: USA
Vessel Name: Czech Mate
Vessel Model: President 41
Join Date: Jan 2017
Posts: 50
Comodave - I'm sure I'm going to reveal my ignorance again, but would another option just be to leave the battery charger lead off the start battery and go ahead and let the ACR combine while on shore power to keep the start batteries charged?
jsplichal2 is offline   Reply With Quote
Old 01-26-2019, 02:38 PM   #12
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 3,672
I suppose you could, but I would go ahead and hook it up. I think that you would get a better and maybe quicker charge on the start battery. Smart chargers look at eack bank and charge them according to their need. If you have 2 banks combined all the time they mau not charge as well. I just have an on/off switch inline with the ground sense wires on my ACRs. When on shore power I just turn the switch off. I have to go to the main power panel when I am hooking/unhooking to shore power anyway.
Comodave is online now   Reply With Quote
Old 01-28-2019, 10:42 AM   #13
Senior Member
 
City: Long Beach
Country: CA
Vessel Model: '81 CHB34
Join Date: May 2014
Posts: 106
Thanks for the replies. Attached is a crude schematic (learning Sketchup) feedback much appreciated.

• Delete OEM battery selector switch at the breaker panel. Wired with 6AWG and runs hot under AC charge load.

• Deleted engine start combine solenoid in ER

• ER install house positive busbar

• ER install alternator/charger shunt

• ER Install ACR

• Install ACR bypass switch at the breaker panel

• Engine start ACR bypass

• ER engine start main battery switch

• ER start bank positive busbar

• Correctly sized terminal fuse installed at each battery (sized to wire rating not load).

• Replace helm amp meter with a voltmeter

• Install shunt supplied amp meter at breaker panel (monitors alternator or AC charger output).

Missing ability to start from house bank (I have jumper cables)

No house bank main disconnect switch... The house bank is fused, is that enough?
Attached Thumbnails
Click image for larger version

Name:	Time Bandit Electrical sub panel.jpg
Views:	34
Size:	46.4 KB
ID:	84690  
winty is offline   Reply With Quote
Old 01-28-2019, 10:49 AM   #14
Senior Member
 
City: Long Beach
Country: CA
Vessel Model: '81 CHB34
Join Date: May 2014
Posts: 106
Larger labels
Attached Thumbnails
Click image for larger version

Name:	Time Bandit Electrical sub panel.jpg
Views:	28
Size:	53.2 KB
ID:	84692  
winty is offline   Reply With Quote
Old 01-28-2019, 11:35 AM   #15
CMS
Senior Member


 
City: Casco Bay
Country: USA
Join Date: Feb 2016
Posts: 206
Quote:
Originally Posted by winty View Post
I'm going through the endless process of untangling and updating the wiring on my 1981 CHB.

I would like to wire up the alternator with an ACR (automatic charging relay), so anytime the engine is running the alternator charges house + engine bank. However, in doing so the ACR switch will be active when the AC charger is powered, which is about 300 days year.

Is it ok to keep the house and engine banks combined for that much time, with AC charger? The house and engine are sized differently, conventional wet acid chemistry.

Most "multi-output" chargers are doing nothing differnt than what an ACR would.
__________________
-CMS

MarineHowTo.com
CMS is offline   Reply With Quote
Old 01-29-2019, 07:15 AM   #16
CMS
Senior Member


 
City: Casco Bay
Country: USA
Join Date: Feb 2016
Posts: 206
Quote:
Originally Posted by winty View Post
Missing ability to start from house bank (I have jumper cables)
If you use an ML-ACR 7622 instead of the 7610SI ACR you will have a manual or contura switch operated parallel option.

Quote:
Originally Posted by winty View Post
No house bank main disconnect switch... The house bank is fused, is that enough?
This is a requirement under ABYC standards.

Beyond that having seen numerous start motors "stuck on" over the years you'll be very glad you have a switch to cut power for a starter motor or a house bank..

About ten years ago I was on a racing sailboat 160nm offshore when I caught a faint whiff of burning electrical. In a split second I dove below and cut both battery switches off. The rest of the crew had no idea what was even going on. The shorted wire, a friction-fit/Fast-On type terminal, only partially insulated not fully insulated, had come loose in the rough seas and shorted and physically welded directly to a DC neg bus.

By the time I cut DC power the 10GA wire had already turned from stranded to solid copper and had zero wire jacket left. It was in the process, & very close to, igniting a piece of wood it passed over.

If I had not had the ability to cut all DC power, and do so quickly, the likelyhood of a fire 160nm offshore was very, very real. While we did have the race rules required offshore equipment, including a life raft, no one wants to actually use those.


This boat did not require a battery switch or a battery fuse and a single G-24 battery did this when the battery cables shorted. Sometimes the ABYC standards simply don't go far enough and common sense needs to take over. Just seconds before this Boston Whaler ignited a few 8 year old "junior sailors" and their coach were on board.

__________________
-CMS

MarineHowTo.com
CMS is offline   Reply With Quote
Old 01-29-2019, 11:08 AM   #17
Senior Member
 
City: Long Beach
Country: CA
Vessel Model: '81 CHB34
Join Date: May 2014
Posts: 106
House bank (not used for engine start). In the case of wire short, will a properly rated fuse at the battery terminal prevent a fire? Vs a fuse + manual cutoff switch?
winty is offline   Reply With Quote
Old 01-29-2019, 11:29 AM   #18
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 661
Quote:
Originally Posted by winty View Post
House bank (not used for engine start). In the case of wire short, will a properly rated fuse at the battery terminal prevent a fire? Vs a fuse + manual cutoff switch?
A fuse at the battery will help in the case of a short circuit. There are many other reasons why you would want to quickly disconnect a battery with a fuse being of no help.
Cigatoo is offline   Reply With Quote
Old 01-29-2019, 01:33 PM   #19
Senior Member
 
FoxtrotCharlie's Avatar
 
City: Mississippi
Country: USA
Vessel Name: ADAGIO
Vessel Model: CHB Present 42 Sundeck
Join Date: Jul 2014
Posts: 493
Quote:
Originally Posted by Comodave View Post
I have twin Lehman SP225s. I know that I could get by with smaller start batteries but the battery boxes are custom made for 4Ds and the house bank isn’t near so I cannot use any of the space to enlarge the house bank.
Our 1988 CHB Present has an identical battery set-up with two huge 4D's as starting bats. I also combine the house and starts while running in order to charge both. Dread ever having to take those 4Ds out, but they are only two yrs old, so maybe not for a while I'm still learning about all of the systems on this boat - oh, the joys! Next I will install a 50 amp galvanic isolator, just in case.
__________________

FoxtrotCharlie is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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





All times are GMT -5. The time now is 07:16 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012