Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 12-07-2017, 00:13   #1
Registered User

Join Date: Jan 2008
Location: 2017 Lagos, Portugal
Boat: Hunter 460
Posts: 5
BATTERY CHARGING WHEN NOT ON BOARD

Hi All,
In addition to a starter battery, I have a house bank of four golf cart batteries which are charged by either the engine (Balmar 105amp) alternator, three 135 watt solar panels, shore power or on-board generator. I also have two AGM batteries for the bow thruster which are only charged via the engineís alternator.
I am away for six months or more when I put the boat up on the hard and I return home to Oz each year. I rely on the solar panels to keep batteries charged but only found out last Oct that the bow thruster batteries are connected only to the alternator.
The boat is presently in Portugal and the yard donít have a solution to charge the bow thruster batteries using the solar panels, they tell me.
Can anyone assist please with a workable solution while Iím away from the boat ie using the solar panels to charge bow thruster batteries as well as starter and house bank.
Many thanks.
Dave
__________________

__________________
David Pakes is online now   Reply With Quote
Old 12-07-2017, 00:17   #2
Registered User

Join Date: Nov 2013
Location: Nice, France
Boat: Hunter Marine 38
Posts: 237
Re: BATTERY CHARGING WHEN NOT ON BOARD

Install an Echo Charger. Will charge the bow thruster batteries only when the house batteries are above a certain set voltage.
__________________

__________________
sailormed is online now   Reply With Quote
Old 12-07-2017, 00:21   #3
Registered User

Join Date: Mar 2013
Boat: Hunter 41
Posts: 24
Re: BATTERY CHARGING WHEN NOT ON BOARD

The problem your going to run into is the different batteries which take different charging voltages. Perhaps a small separate panel and controler for the AGMs just to keep them trickle charged not to make up for thruster use.
__________________
uncledom is offline   Reply With Quote
Old 12-07-2017, 00:26   #4
Registered User

Join Date: Nov 2013
Location: Nice, France
Boat: Hunter Marine 38
Posts: 237
Re: BATTERY CHARGING WHEN NOT ON BOARD

If you are on the hard with access to 220V, install a trickle battery charger only for the AGM thruster batteries.
__________________
sailormed is online now   Reply With Quote
Old 12-07-2017, 04:24   #5
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 30,950
Images: 240
Re: BATTERY CHARGING WHEN NOT ON BOARD

Greetings and welcome aboard the CF, Dave.
__________________
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 12-07-2017, 04:27   #6
Registered User
 
ranger42c's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 42' Sportfish
Posts: 2,765
Re: BATTERY CHARGING WHEN NOT ON BOARD

Our AGMs have never self-discharged very much over longish winter periods...

-Chris
__________________
Selby Bay, South River, Chesapeake Bay, USA.
ranger42c is offline   Reply With Quote
Old 12-07-2017, 09:58   #7
Marine Service Provider

Join Date: Jan 2012
Location: Lake Ontario
Boat: Douglas 32 Mk II
Posts: 1,508
Re: BATTERY CHARGING WHEN NOT ON BOARD

For only six months, disconnect the negative terminals of all batteries.
__________________
Rod Brandon
Sheen Marine
ramblinrod is offline   Reply With Quote
Old 12-07-2017, 11:06   #8
Registered User

Join Date: Oct 2007
Posts: 25
Re: BATTERY CHARGING WHEN NOT ON BOARD

Quote:
Originally Posted by ramblinrod View Post
For only six months, disconnect the negative terminals of all batteries.
Why go through the trouble of disconnecting all batteries? David says all batteries are fine with the solar panels keeping them charged except the two that provides local peak power to the bow thruster.
Actually David also said that one alternator charges all the batteries which implies that all the batteries can be connected in parallel through switches.
Can't be certain without looking at a wiring diagram but it sounds like the problem can be made to go away by leaving the right set of switches closed.
Ahmet
__________________
Ahmet Erkan is offline   Reply With Quote
Old 12-07-2017, 11:43   #9
Registered User
 
ccannan's Avatar

Join Date: Jun 2003
Boat: Alubat, OVNI 47
Posts: 178
Images: 5
Re: BATTERY CHARGING WHEN NOT ON BOARD

I disconnect my batteries while away from my boat over an extended period of time (boat in the boatyard). I have AGMs and leave my boat for periods of up to 9 months and haven't noticed any appreciable battery discharge, or any other negative effects. I also disconnect my solar panels from my solar charger. I had a solar charger die on me one winter when I had left it and the batteries connected.

Another reason to disconnect the batteries is to eliminate any possible discharge and or ignition source for a fire.
__________________
Chip
ccannan is offline   Reply With Quote
Old 12-07-2017, 12:18   #10
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 12,555
Re: BATTERY CHARGING WHEN NOT ON BOARD

Put a small portable charger, even a car battery charger, on an extension cord and top off the AGMs for a day every second or third month, and they'll be happy enough. It isn't perfect but it is very simple and inexpensive. AGMs don't self-discharge at the same rate that wet cells do. Or, leave one portable solar panel on deck, on the bow, to keep a small charger going on the AGMs.
__________________
hellosailor is offline   Reply With Quote
Old 12-07-2017, 14:22   #11
Registered User

Join Date: Aug 2007
Location: Adelaide, South Australia, sailing in the Med.
Boat: Beneteau, Oceanis 50
Posts: 386
Re: BATTERY CHARGING WHEN NOT ON BOARD

Quote:
Originally Posted by David Pakes View Post
Hi All,
In addition to a starter battery, I have a house bank of four golf cart batteries which are charged by either the engine (Balmar 105amp) alternator, three 135 watt solar panels, shore power or on-board generator. I also have two AGM batteries for the bow thruster which are only charged via the engineís alternator.
I am away for six months or more when I put the boat up on the hard and I return home to Oz each year. I rely on the solar panels to keep batteries charged but only found out last Oct that the bow thruster batteries are connected only to the alternator.
The boat is presently in Portugal and the yard donít have a solution to charge the bow thruster batteries using the solar panels, they tell me.
Can anyone assist please with a workable solution while Iím away from the boat ie using the solar panels to charge bow thruster batteries as well as starter and house bank.
Many thanks.
Dave
We are in a similar situation Dave. We leave ours in the Med and return to Australia for 9 months or so each year. I have not looked at the Hunter wiring, but there is more than a good chance it is similar to ours.

We have generator start, engine start, 4 x service batteries, and 4 x bow thruster batteries. Normally they are all (except the generator) charged from engine or shore power, through a series of splitters. When we leave, I turn all of the isolators off. The charging points go to the battery side of the isolators, so charging is maintained, but the batteries are otherwise totally isolated from the boat.

Charging therefore continues when the yard plugs the power in each month. However with the gen-start battery, (in your case, the bow-thruster batteries) I have a dedicated outlet of the solar controller (a dual battery version) feeding that battery, and the other outlet feeding all other batteries through a splitter. The alternative is as others have suggested - a small charger going to the BT batteries.

Having said all of that, are you sure the BT batteries are only charged by the engine? Perhaps the splitter input from the shore charger(s) is faulty?

I hope that helps. We will be back in Australia in a week if you want to chat about it.

David
__________________
David B is offline   Reply With Quote
Old 12-07-2017, 22:43   #12
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Brisbane
Boat: 45ft Ketch
Posts: 1,118
Re: BATTERY CHARGING WHEN NOT ON BOARD

Quote:
Originally Posted by ranger42c View Post
Our AGMs have never self-discharged very much over longish winter periods...

-Chris
I understood one of the benefits of AGM was that you could leave it 6 months without any issues. Probably why the solar is not connected.

I'm planning to put them in my little motorhome for that reason.
__________________
DumnMad is online now   Reply With Quote
Old 16-07-2017, 19:44   #13
Registered User

Join Date: Jan 2008
Location: 2017 Lagos, Portugal
Boat: Hunter 460
Posts: 5
Re: BATTERY CHARGING WHEN NOT ON BOARD

Hi All,

Thank you so much for your very helpful advice and thank you also for the welcome. Lots of good solutions as I anticipated. I think it might be time I did a bit more homework myself and see what might be best and/or simplest for our boat. Any further suggestions always welcome.

Cheers
David
__________________
David Pakes is online now   Reply With Quote
Old 16-07-2017, 20:32   #14
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Brisbane
Boat: 45ft Ketch
Posts: 1,118
Re: BATTERY CHARGING WHEN NOT ON BOARD

Hi David.
Seems like the electrician knew what they was doing by putting the AGM's at the bow-thruster and no connection to the solar. I suggest leave everything as is but get the yard to top up the water in the solar powered golf cart batteries from time to time while you are away.
__________________
DumnMad is online now   Reply With Quote
Old 17-07-2017, 09:58   #15
Registered User

Join Date: Oct 2007
Posts: 25
Re: BATTERY CHARGING WHEN NOT ON BOARD

Quote:
Originally Posted by DumnMad View Post
Hi David.
Seems like the electrician knew what they was doing by putting the AGM's at the bow-thruster and no connection to the solar. I suggest leave everything as is but get the yard to top up the water in the solar powered golf cart batteries from time to time while you are away.
The electrician might have known AGM batteries are more vulnerable to overcharging but I do not agree with not charging at all as a solution.
Batteries should be fully charged and then left on a "trickle charge" if they are to be stored for an extended time.
A trickle charger helps keep the batteries healthy when the boat is stored on the hard for a lengthy period, but much more importantly the bilge pump shall be operational if the boat is unattended at the slip.
Unfortunately the battery manufacturers do not specify the parameters for a trickle charge. I use a maximum Watts/sqft of dissipative surface area of the battery bank but I don't want the responsibility of suggesting a figure because it should be specified by the battery manufacturers for an allowable temperature rise that does not cause loss of water. The charger should also be smart enough to recharge faster if a load is applied such as a bilge pump activation.
Nothing is easy in engineering.
Cheers.
__________________

__________________
Ahmet Erkan is offline   Reply With Quote
Reply

Tags
battery, charging

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
How to test Xantrex Freedom 20 Echo Charger output - not charging aux battery PamlicoTraveler Electrical: Batteries, Generators & Solar 9 07-05-2017 19:46
To board or not to board, that is the question liveaboard60 Liveaboard's Forum 82 28-07-2016 12:50
Gell Cell battery not charging, lead acid batteries charge fine. roverhi Electrical: Batteries, Generators & Solar 7 28-03-2016 10:31
charging a small battery from a larger battery danielb Electrical: Batteries, Generators & Solar 15 26-01-2015 17:22
Battery Charging, Battery Return amps and Victron inthejungle Marine Electronics 2 16-09-2013 12:36


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- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 23:45.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.