Notices
Marine Electronics Forum

Battery quiestion

Old 03-24-2007, 07:02 PM
  #1  
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Bethlehem,PA
Posts: 291
Likes: 0
Received 0 Likes on 0 Posts
Default Battery quiestion

I have two brand new group 27 AGM batteries. What is the correct way to connect them together?

I have a negative cable going from one negative baery to the other is this correct?

I dont have to do a positive also do I?
Old 03-24-2007, 07:36 PM
  #2  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Feb 2005
Location: Kent Narrows, MD
Posts: 7,144
Received 774 Likes on 366 Posts
Default Re: Battery quiestion

What type of boat ?

How many engines ?

What type of engines ?

Currently any batt switches ?



Old 03-24-2007, 08:32 PM
  #3  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Jan 2004
Location: Portsmouth, RI 02871
Posts: 2,059
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Battery quiestion

he positives should go thru a dual On/Off switch
Old 03-25-2007, 07:32 AM
  #4  
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Bethlehem,PA
Posts: 291
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Battery quiestion

1997 Trophy 2352 Walkaround, I have a 5.7 Mercruiser and I do have a switch that says 1, 2, both and off. I would like both batteries to charge from the boat alternator and at home in my driveway from this battery tender I bought. There is positive cables coming from the switch and I think i have them going to both battery positive terminals.
Also when I charge the batteries at home should I put the switch on for both batteries, or put it on off?
Old 03-25-2007, 09:18 AM
  #5  
Senior Member
 
Join Date: Nov 2006
Location: Kent Island, MD
Posts: 2,179
Likes: 0
Received 269 Likes on 178 Posts
Default Re: Battery quiestion

If it's just one battery switch, it should be wired with the positive cable from each battery going to the switch posts 1 & 2, and the 3rd cable coming off of the switch and going to the starter solenoid. Either battery should charge off the alternator as you're using it (if on bat #1 - it will charge, while bat #2 will be isolated. If using bat #2 - it will charge while bat #1 remains isolated). If you put the switch on "both", they will both charge at the same time. The only problem with using "both" is, if one of your batteries is low, it will draw the other one down to the same level. Any time they are hooked together this way (parallel) the batteries will equalize in charge.
Same deal if it's sitting in your driveway on a charger. If the switch is set to "both", a charger hooked to either battery will charge both - but if one is bad, it will draw down the other. You should probably charge them one at a time with the switch set to "off", or invest in some type of isolator to avoid the draw down factor.
Old 03-25-2007, 12:33 PM
  #6  
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Bethlehem,PA
Posts: 291
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Battery quiestion

Thanks, I must have them hooked up correctly because they are both charging on this charger/maintainer I bought.

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 On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.