Thread Tools Search this Thread Display Modes
Old 05-15-2009, 02:01 PM   #1
2 Rivet Member
1974 25' Tradewind
Monument , Colorado
Join Date: Apr 2009
Posts: 41
Dual Batteries

Question. Can I charge 2 batteries simultaneously hooked together in parallel with either a portable charger or on-board charger. Since I'm new to this and don't want to damage my newly renovated ship, I'm seeking knowledge of how to set this up.



seeflash is offline   Reply With Quote
Old 05-15-2009, 02:27 PM   #2
Site Team
, Minnesota
Join Date: Aug 2003
Posts: 7,098
Images: 59

If you leave them hooked together for a long time, the weaker one will tend to drag down the stonger one. Not a problem while charging though.

If they're identical batteries made at the same time, they should work well together.

markdoane is offline   Reply With Quote
Old 05-15-2009, 02:30 PM   #3
1 Rivet Member
1966 30' Sovereign
1979 24' Airstream Excella 24
Enumclaw , Washington
Join Date: Apr 2009
Posts: 5
Blog Entries: 3

Don't forget they should be the same size, type, age, and amperage.
sovereign66 is offline   Reply With Quote
Old 05-17-2009, 09:15 PM   #4
Rivet Master
1975 29' Ambassador
Reno , Nevada
Join Date: May 2003
Posts: 1,351
re "the weaker one will tend to drag down the stonger one" - common myth but not quite that simple.

It is good advice to try to match batteries in a bank as closely as possible to aid in longer life but a 'weaker' battery will not damage or destroy a stronger one or drag it down as long as they are the same chemistry. What happens is that the stronger one just works harder in proportion to its strength compared to the weak one. All batteries of the same chemistry in a parallel bank will give and take charge in proportion to their capacity.
bryanl is offline   Reply With Quote
Old 05-17-2009, 09:47 PM   #5
Rivet Master
Mexray's Avatar
1978 28' Ambassador
Morada , California
Join Date: Jan 2006
Posts: 1,583
You can charge em' both at the same time...

If you're using a 'portable' charger, when the batteries are hooked in parallel (pos - pos, neg -neg) it's best to hook the POS charge lead on one battery, and the NEG charge lead on the OTHER battery - that way you'll have about the same level of charge for both, as the resistance in the parallel cables and connections tend to even out.

If I'm setting up a battery bank, I like to hook up the cables going to the Load, in the same manner...however your batteries probably aren't hooked up that way in your trailer, at lease mine aren't - each pair of leads come into the fuse panel and are hooked together there - but it works just fine.
Ray & Pat; Morada, CA
Mexray is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Upgrading my CCD to dual batteries silverback Electrical - Systems, Generators, Batteries & Solar 7 05-20-2008 07:58 AM
Dual Alternators Craftsman Off Topic Forum 1 06-02-2004 01:27 PM
Dual Batteries trning 2003 Safari 0 03-29-2004 11:01 PM
Dual Gray Water & Dual Black Water? nvestysly Waste Systems, Tanks & Totes 5 05-09-2003 05:40 AM
Univolt/Dual Batteries uwe Batteries, Univolts, Converters & Inverters 4 06-28-2002 08:26 PM

Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:57 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.