Using a portable battery charger onboard - SailNet Community
Reply
 
LinkBack Thread Tools
post #1 of 20 Old 11-04-2008 Thread Starter
Senior Member
 
AdamLein's Avatar
 
Join Date: Nov 2007
Location: SF Bay area
Posts: 1,924
Thanks: 6
Thanked 7 Times in 6 Posts
Rep Power: 8
 
Using a portable battery charger onboard

I got this portable battery charger from West Marine to charge the deep cycle / starting batteries (a pair of Walmart-brand 12V cells, model no. "24-DC", 75 Ah each) on my boat. I got it instead of the $10-more-expensive "onboard charger", not knowing that the instructions said that a marine battery must be removed from the boat and charged onshore.

What's the reason for this requirement? I figure if the 6A alternator on my outboard is okay to use on the boat, why not a 6A charger? Is it because there's a power cable running from shore or something?

So the first time I used it, I lugged the batteries to shore. Egads, were they heavier than I expected. Also they are not stowed in super-accessible locations (like, under the v-berth). I really really want to just attach the alligator clamps to the terminals in the engine compartment. Will Ι create any micro black holes if I do this?
AdamLein is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 20 Old 11-04-2008
Senior Member
 
tommays's Avatar
 
Join Date: Sep 2008
Posts: 4,296
Thanks: 1
Thanked 30 Times in 30 Posts
Rep Power: 7
 


I would say the danger would be from leaving it in a gasoline powered boats engine compartment WHICH would require and ignition safe charge


If your just charging a battery on a boat i am not seeing the danger

1970 Cal 29 Sea Fever

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1981 J24 Tangent 2930
Tommays
Northport NY


If a dirty bottom slows you down what do you think it does to your boat
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
tommays is offline  
Quote Quick Reply Share with Facebook
post #3 of 20 Old 11-04-2008
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 15 Times in 12 Posts
Rep Power: 14
         
Adam-

Which battery charger did you get? Is it an intelligent three-stage charger? If not, it will probably likely fry your batteries...

Most portable battery chargers aren't recommended for use on a boat as they can be a fire hazard. The alligator clips can come loose unexpectedly, and that can be bad. Also, it requires you to open the battery box to have the clips attach to the battery posts, and if you leave the battery box open and something falls across the posts...bad things can happen.

If you want to charge the batteries on the boat, you're much better off hardwiring in a proper marine battery charger into the system.

Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #4 of 20 Old 11-04-2008
Bear
 
Join Date: Oct 2008
Location: Vancouver Island British Columbia canada
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Battery Caharging on board

In addition to the dangers of heavier than air volotile gases such as gasoline vapour and propane; a battery, while being charged also generates a small amount of equally explosive hydrogen gas (think Hindenberg) any of these volitile gases could be ignited by a connect / disconnect spark. If you must charge on board, ensure adequate ventilation to remove all of these gases (think bilge blower) prior to connection or disconnection. Also to limit the possibility of sparking near the battery, make charger leads fast to battery terminals then plug it in at farthest reach of it's power cord. This should eliminate sparking at the battery (assuming the red is to + ,black is to - terminals).
carebear186 is offline  
Quote Quick Reply Share with Facebook
post #5 of 20 Old 11-04-2008
Senior Member
 
Join Date: Sep 2003
Posts: 268
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 12
 
Quote:
Originally Posted by sailingdog View Post
Adam-

Which battery charger did you get? Is it an intelligent three-stage charger? If not, it will probably likely fry your batteries...
I'm not understanding why a regular old battery charger is going to "fry" my batteries. I've charged car batteries all the time and haven't fried anything. I've also charged the boat batteries with the same result. A battery is a battery. If you're not permanently hooking up the charger for long-term constant use I don't see the problem. I think this guy is just charging up as needed.

"There's a wind in my sails that protects and prevails." - "Six Months in a Leaky Boat", Split Enz
sander06 is offline  
Quote Quick Reply Share with Facebook
post #6 of 20 Old 11-04-2008
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 15 Times in 12 Posts
Rep Power: 14
         
Sander-

An older style battery charger will not have bulk, absorption and float stages... and as such will generally run at a higher voltage than the battery requires when it is nearly fully charged... and doing so generates excess heat and boils off electrolyte in the case of wet-cells, and just fries the gel in gel cells and AGMs.. If he leaves an old-style battery charger connected for any significant period of time... which is necessary to get the batteries up to 100%, he runs a much higher risk of frying them if it isn't a smart charger.

Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #7 of 20 Old 11-04-2008
Senior Member
 
Maine Sail's Avatar
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,889
Thanks: 20
Thanked 223 Times in 170 Posts
Rep Power: 16
       
Quote:
Originally Posted by sander06 View Post
I'm not understanding why a regular old battery charger is going to "fry" my batteries. I've charged car batteries all the time and haven't fried anything. I've also charged the boat batteries with the same result. A battery is a battery. If you're not permanently hooking up the charger for long-term constant use I don't see the problem. I think this guy is just charging up as needed.

Basic, cheap battery chargers generally charge at only 14.4 - 14.6 volts regardless of the acceptance rate of the battery being charged.

A "smart" charger will charge at, depending upon the battery type setting, 14+ for the bulk phase, 13.8 for the absorption phase and 13.2-13.4 for the float phase thus causing no damage to the batteries.

______
-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.


Maine Sail is offline  
Quote Quick Reply Share with Facebook
post #8 of 20 Old 11-04-2008
Senior Member
 
HerbDB's Avatar
 
Join Date: Sep 2000
Location: Eastern Pennsylvania
Posts: 203
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 15
 
I think most of the replys assume you will attach the charger and leave it connected for the winter. If so, they are correct. You need a smart charger that will not overcharge the batteries.

If the intent is to periodically top off the batteries by attaching the charger for a couple of hours, then I see no problem. I use this technique when my boat is on the hard for the winter.

Herb DuBois
Beneteau 36CC
Split Decision
HerbDB is offline  
Quote Quick Reply Share with Facebook
post #9 of 20 Old 11-04-2008
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 15 Times in 12 Posts
Rep Power: 14
         
HerbDB-

If you're using a "dumb" charger to top off the batteries, you should check the water level more often than if you're using a smart charger.

Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #10 of 20 Old 11-04-2008
Irrationally Exuberant
 
Join Date: Jul 2007
Location: Northern Virginia
Posts: 1,333
Thanks: 9
Thanked 6 Times in 6 Posts
Rep Power: 9
 
I got my batteries through last winter on the hard using an old automotive charger. I might have had it plugged in for 5 or 6 hours every few weeks or so. Didn't notice any more frying than they already appeared to be I only used the charger while I was there doing work or hanging with the boat, never left it running unattended.

Tom K

2000 Beneteau 331
Northern Chesapeake Bay

Ambition is a poor excuse for not having enough sense to be lazy ~ Steven Wright
arf145 is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

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
Installing a Automatic Battery Selector Switch artbyjody Gear & Maintenance 24 07-08-2008 07:07 PM
Sizing a Battery Charger for Windlass Battery btrayfors Gear & Maintenance 9 04-11-2007 12:43 AM
Battery Bank Design Kevin Jeffrey Gear and Maintenance Articles 0 05-12-2003 08:00 PM
Installing a New Battery Bank Sue & Larry Gear and Maintenance Articles 0 09-26-2002 08:00 PM
Boat Battery Power East Penn Manufr. Gear and Maintenance Articles 0 01-18-1999 07:00 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