Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 05-03-2019, 20:54   #1
Registered User

Join Date: Jan 2009
Location: Home port is San Diego, California, but Rutea is currently cruising the west coast of Central America.
Boat: Contest 48
Posts: 946
Images: 1
Strange Electrical Problem

We have been cruising for eight years and have a pretty good grasp of our electrical system. We installed eight new 224-amp 6-volt AGM batteries slightly over a year ago and they have been great. To charge the batteries, we have two 225-watt solar panels and a single-cylinder Kubota diesel with a 150-amp Leece-Neville 12-volt alternator which is regulated by a Balmar MC-614 external regulator. Iím embarrassed to admit it but weíre power hogs. We draw a lot of amps out of our batteries and have to put a lot back in.

I usually wait until I see 12.1 or less volts in the battery bank before I start the single-cylinder Kubota and Iíll initially see about 135 amps going into the batteries but it will taper down to about 100 amps pretty quickly. Once the batteries are only accepting about 50 amps, which takes about 90-120 minutes, I shut the engine down.

However, just recently Iíll only see a maximum of 70 amps going in on start up and then it quickly tapers down to about 40 amps. Granted, weíre mostly out of the tropics (24įN) and the demand from the refrigerator and freezer are less but that shouldnít affect the charge rate. My first suspicion was a problem with either the alternator or the regulator so I tried charging with the main engine.

About ten years ago, I installed a 90hp Beta Marine with two Iskra alternators - a 100-amp (which we only use to charge the starting battery) and an internally-regulated 150-amp alternator to charge the house battery bank. Itís been a great, trouble-free system but you can imagine my surprise when I started the Beta Marine and got the exact same charging issues that I have with the single-cylinder Kubota.

Since the output of all three charging sources (solar, single-cylinder Kubota and the Beta Marine) terminate on one side of a 300-amp ĎTí fuse, I suspected that the fuse could have developed some sort of internal resistance so I replaced it with a new spare I had on hand. No change.

I keep the serpentine belts tightened to factory specs which is 12mm of deflection when 8 kilos of force are applied at mid-span - it feels banjo string-tight to me but I havenít had any belt or bearing failures and the Beta Marine has almost 5,000 hours on it.

Of course, Iíve checked, cleaned and tightened all the connections. Everything electrical that I assemble gets generously coated with Lanocoat grease and I think that has helped keep everything so trouble-free.

Thank you for reading this far. I know itís complicated. What could have changed so the batteries will suddenly only accept about half of the charge they accepted last week? Or, why are two different alternators suddenly only putting out half the amps they were outputting last week? If you have any ideas or suggestions, Iíd like to hear them.

Fair winds and calm seas.
__________________

nhschneider is offline   Reply With Quote
Old 05-03-2019, 21:08   #2
Registered User

Join Date: Jan 2017
Posts: 4
Re: Strange Electrical Problem

Just a thought but have you confirmed the device or gauge you are using to measure with is reading your amps correctly?
__________________

Farmer9009 is offline   Reply With Quote
Old 05-03-2019, 21:31   #3
Registered User

Join Date: Apr 2006
Location: Alpharetta ga
Boat: 2010 Leopard 38
Posts: 65
Strange Electrical Problem

My guess would be that the capacity is much lower because of how far (and often) they have been discharged. Since they have lost the capacity, the input tapers off much faster. 12.1v is a pretty low voltage.

I will hang up now and wait for the experts to chime in.
RonRicco is offline   Reply With Quote
Old 05-03-2019, 22:21   #4
Registered User

Join Date: Oct 2018
Posts: 8
Re: Strange Electrical Problem

Not an expert, but I'm getting ready to convert from Lead Acid to AGM and I found this discussion by someone with the moniker Maine Sail insightful.

https://forums.sailboatowners.com/in...choice.124973/

Sean
disputin is offline   Reply With Quote
Old 05-03-2019, 22:34   #5
Registered User

Join Date: Jun 2013
Location: canada
Posts: 2,593
Re: Strange Electrical Problem

Do you ever get them to 100%? Sounds not which is murdering your AGms.

Fireflys would help you due to you never fully charging.


You can test the charging by putting a huge load on the battery. Ie if you have an inverter. Put a hairdryer or 1500w heater on. If you are drawing 150a from the batt the alt should put out 150a even if the batteries suck. If the charging now fully works. The batteries are the issue. If it still only puts out 70a. You have other issues.
smac999 is online now   Reply With Quote
Old 05-03-2019, 23:30   #6
Registered User

Join Date: Jan 2009
Location: Home port is San Diego, California, but Rutea is currently cruising the west coast of Central America.
Boat: Contest 48
Posts: 946
Images: 1
Re: Strange Electrical Problem

Quote:
Originally Posted by Farmer9009 View Post
Just a thought but have you confirmed the device or gauge you are using to measure with is reading your amps correctly?


I have a Xantrex Link-Pro installed but the single-cylinder Kubota also has an amp gauge. They both seem to show the same about number of amps going in.
nhschneider is offline   Reply With Quote
Old 05-03-2019, 23:37   #7
Registered User

Join Date: Jan 2009
Location: Home port is San Diego, California, but Rutea is currently cruising the west coast of Central America.
Boat: Contest 48
Posts: 946
Images: 1
Re: Strange Electrical Problem

Quote:
Originally Posted by RonRicco View Post
My guess would be that the capacity is much lower because of how far (and often) they have been discharged. Since they have lost the capacity, the input tapers off much faster. 12.1v is a pretty low voltage.

I will hang up now and wait for the experts to chime in.


Correct me if Iím wrong but if I discharge to 12.1 volts, thatís barely a 50% discharge. These batteries should be able to endure at least a 1,000 discharges that are no more than 50%, shouldnít they? Theyíve probably had around 400.

Iím not trying to be argumentative. If there are flaws in my thinking, please let me know.
nhschneider is offline   Reply With Quote
Old 05-03-2019, 23:44   #8
Registered User

Join Date: Jan 2009
Location: Home port is San Diego, California, but Rutea is currently cruising the west coast of Central America.
Boat: Contest 48
Posts: 946
Images: 1
Re: Strange Electrical Problem

Quote:
Originally Posted by smac999 View Post
Do you ever get them to 100%? Sounds not which is murdering your AGms.

Fireflys would help you due to you never fully charging.


You can test the charging by putting a huge load on the battery. Ie if you have an inverter. Put a hairdryer or 1500w heater on. If you are drawing 150a from the batt the alt should put out 150a even if the batteries suck. If the charging now fully works. The batteries are the issue. If it still only puts out 70a. You have other issues.


Actually, on our passage from Panama to Mexico we had to motor almost the entire way so the batteries did get fully charged then. Just recently, we had to motor almost the entire way from Isla Socorro to Bahia Los Frailes, a distance of almost 300 miles and the batteries showed that they were fully charged then, too.

I like your suggestion for putting a big load on the batteries while charging. Iíll give that a try.
nhschneider is offline   Reply With Quote
Old 05-03-2019, 23:49   #9
Registered User
 
Sojourner's Avatar

Join Date: Oct 2017
Location: On the boat!
Boat: SY Wake: 53' Amel Super Maramu
Posts: 657
Re: Strange Electrical Problem

I don't know much about batteries yet unfortunately, but I do know the specs for my batteries (AGM) and victron/sterling chargers call for something like 55 amps charging rate, not more, which is where they're set. Don't know if that's an issue or not for you...
__________________
3 cats, 3 queers, endless wake, endless love!
https://www.facebook.com/anendlesswake/
https://anendlesswake.com/
Sojourner is online now   Reply With Quote
Old 05-03-2019, 23:50   #10
Registered User

Join Date: Nov 2013
Location: Nice, France
Boat: Hunter Marine 38
Posts: 575
Re: Strange Electrical Problem

"I usually wait until I see 12.1 or less volts in the battery bank before I start the single-cylinder Kubota.......". Is this after the batteries have been without load for a certain. time?
The battery charge % based upon voltage is after a period of no charge to let the batteries recover. Officially 24 hours I think, but after 1 hour you already get a good approximation.
sailormed is offline   Reply With Quote
Old 06-03-2019, 00:09   #11
Registered User
 
Simi 60's Avatar

Join Date: Jun 2016
Location: Australia
Boat: Milkraft 60 ex trawler
Posts: 1,894
Re: Strange Electrical Problem

Showing fully charged does not necessarily mean they are.
Our batts usually show fully charged (100% and 0 ah used) by 11am but the solar panels are still pushing tapered off amps into those batteries until the sun disappears.
Simi 60 is offline   Reply With Quote
Old 06-03-2019, 04:03   #12
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 35,893
Images: 241
Re: Strange Electrical Problem

Greetings and welcome aboard the CF, Sean.


12.1V represents a state of charge of about 50%, the maximum level to which you want to discharge.
If the batteries are accepting 50 Amps, they are nowhere near fully charged.
__________________
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 06-03-2019, 04:40   #13
Senior Cruiser
 
Sailmonkey's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 7,284
Strange Electrical Problem

Quote:
Originally Posted by GordMay View Post
Greetings and welcome aboard the CF, Sean.


12.1V represents a state of charge of about 50%, the maximum level to which you want to discharge.
If the batteries are accepting 50 Amps, they are nowhere near fully charged.


Agreed

12.1 is pretty depleted, you have 896 ah of batteries.

Running the generator to replace the 448 ah of consumed power should take minimum (it will be much longer) 4-5 hours. Reality is that 100% will take 6-10 hours of charging. 50 amps going into the batteries is them still charging, not them charged.

I hate to say it, but youíve murdered you agm batteries by never fully charging them.
Sailmonkey is offline   Reply With Quote
Old 06-03-2019, 04:43   #14
Registered User

Join Date: Jan 2008
Location: Caribbean
Boat: Island Spirit 401 Catamaran
Posts: 474
Re: Strange Electrical Problem

I’ve had a similar issue but it is isolated to one charging source. I’m still trouble shooting it but at this point I pretty sure it is wiring. (One engine/alternator produces high amps, the second set significantly lower but both have separate cables running to the same battery bank and switched out alternators). I am going to try looking for resistance using an ohm meter next. Let us know what you find.

BTW AGMs are not usually considered the best for deep cycling. You need to read the lit from companies that sell several types to get more truthful info. Hope it is not that.
Ostinato is offline   Reply With Quote
Old 06-03-2019, 04:48   #15
Registered User

Join Date: Feb 2018
Location: Maryland
Boat: Bristol 53.3, 1988
Posts: 21
Re: Strange Electrical Problem

Agree with smac and others... if that bank is still accepting 50A when you turn off the genset, you're still in bulk charging stage and haven't fully recharged in a long while!

The good news is you probably don't need a new genset or alternators.
__________________

jkimbu is offline   Reply With Quote
Reply

Tags
cal, electric, electrical

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Strange Generator Problem Dockhead Electrical: Batteries, Generators & Solar 32 16-09-2016 10:06
Strange solar panel problem colemj Electrical: Batteries, Generators & Solar 4 20-01-2015 14:33
Strange engine problem argalax Engines and Propulsion Systems 9 24-10-2014 03:59
Strange ST4000+ problem maersi Marine Electronics 2 10-12-2013 02:12
A Strange Problem with a Desktop PC and an Inverter sdowney717 Marine Electronics 9 27-08-2011 08:59



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:50.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.