Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 18-07-2010, 13:41   #1
Registered User
Olorin's Avatar

Join Date: Aug 2009
Location: On the Boat
Boat: Fortuna, Island Spirit 400, 40ft. Catamaran - S/V One White Tree
Posts: 107
Battery Charging Question

Here's the situation:

I have
  1. A Mastervolt IVO SMart 12/25-2 battery charger(12 volts 25 amps);
  2. Four new DEKA Pro Master GC15 6 volt 230 AHr, arranged to give me 12 volts and 460AHr; and,
  3. A Xantrex Link 1000 display.
The charger has been plugged in for a week and it is still in Bulk charge mode. It is putting in between 5 and 6 amps at 14.40 volts. [Note: Bulk is supposed to last for no more than 6 hours and stop when the voltage hits 14.25] Once, for a brief time after running the engines, I saw the voltage drop to 13.25 and the current drop to 1.0. This didn't last long though.

The batteries are not hot, nor are they emitting any water. They seem fine with this situation.

  1. Am I hurting my Batteries?
  2. Is my charger's little electronic brain scrambled?
  3. Is the charger just too undersized?
Thanks in advance from the Harbour View Marina in Marsh Harbour, Abaco, Bahamas.

"And all I ask is a merry yarn from a laughing fellow-rover
And quiet sleep and a sweet dream when the long trick's over."
John Masefield
Olorin is offline   Reply With Quote
Old 18-07-2010, 14:23   #2
Nearly an old salt
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Sounds to me like it's in absorbtion mode and given it's small size could stay there forever especially if there are constant dc loads that the charger is also supplying


goboatingnow is offline   Reply With Quote
Old 18-07-2010, 14:33   #3
Moderator Emeritus
David M's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: San Francisco Bay
Boat: research vessel
Posts: 9,844
13.25 is the resting voltage for the charger, a few amps output would be normal just to provide a trickle charge. If it is not staying there for long and popping back up to 13.8 or so I suspect you have an intermittent load on your batteries from something.

Life begins where land ends.
David M is offline   Reply With Quote
Old 18-07-2010, 14:39   #4
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 2,966
Do you have any 12v stuff running? Refrigerator/Freezer?

I have the Trojan T-105s that are real close to your Deka's. Trojan recommends charging at a rate of 10-13% of capacity. In your case, this would be a 50-60amp charger. I have a 50amp shorepower charger and a 90amp alternator, and neither has any problem charging the T-105s.
DotDun is offline   Reply With Quote
Old 18-07-2010, 17:04   #5
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 3,925
Images: 4
Sounds very much like you have a DC load on the batteries which the little charger is struggling to keep up with. Frig, maybe?

Yes, the charger is a bit undersized for the battery bank you have. A charger in the 50-75A range would be better. In your stead, I'd be tempted to pick up an Iota DLS-55/IQ4 or DLS-75/IQ4 to handle the battery charging task, keeping the Mastervolt in reserve for when you are dockside and don't have any DC loads of significance. These chargers are relatively inexpensive and do a terrific job....under $200. Check on eBay or on Arizona Wind and Sun's site (excellent supplier).

Are you hurting your batteries? Probably not in the short-term, but matching the charger to the house battery bank and characteristic DC load would be a good idea.


btrayfors is offline   Reply With Quote


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
Solar Battery Charging elangley Electrical: Batteries, Generators & Solar 8 19-07-2010 09:50
Battery Charging Problem skatrijk Electrical: Batteries, Generators & Solar 6 20-03-2010 05:31
Battery-Charging Voltages Rick Electrical: Batteries, Generators & Solar 41 05-05-2009 20:23
Battery selection and charging mestrezat Electrical: Batteries, Generators & Solar 18 08-07-2008 21:03
Generator battery charging question? avazquez Electrical: Batteries, Generators & Solar 4 10-09-2007 06:47

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 02:03.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.