Thread Tools Search this Thread Display Modes
Old 01-31-2015, 10:52 AM   #1
2 Rivet Member
2015 25' FB Flying Cloud
Georgetown , Texas
Join Date: Oct 2012
Posts: 77
Images: 3
Keeping Batteries Charged

I know there are numerous posts on this forum regarding battery charging, and I've read most of them. At this point I'm almost glassy eyed, and in search of a simple, straightforward explanation.

I'm obviously a newbie, and I continue to worry about the batteries in our AS, which is stored at a facility not far from our home. I've hooked a trickle charger up to the batteries, but it never did indicate a full charge...the light stayed red rather than turning green. The monitor inside the trailer indicated that the batteries were at 14.1 after two days. I disconnected the charger yesterday, and when I returned this morning the monitor had the batteries down to one night, with the nighttime low somewhere in the 40s. The battery disconnect switch is set to "store", so the only draw on the battery is the CO2 detector.

My question: When you hook a battery trickle charger, such as the Battery Tender, up to the two battery configuration that the AS has, is one charger enough, or should I hook a separate charger up to each battery and charge simultaneously? I used a single charger, with the positive going to the positive post of one battery, and the negative going to the negative post of the other battery. Is there a problem with that? Thank you in advance for any advice.

GLovedahl is offline   Reply With Quote
Old 01-31-2015, 11:30 AM   #2
Site Team
azflycaster's Avatar
2002 25' Safari
Dewey , Arizona
Join Date: Mar 2005
Posts: 13,022
Images: 62
Blog Entries: 1
The 14.1 was not the battery, but the output of the charger. Fully charged is around 12.6-12.8, so 12.5 is pretty close (90%) plus there could be a small inaccuracy in your measuring device.



Wally Byam Airstream Club 7513
azflycaster is offline   Reply With Quote
Old 01-31-2015, 11:48 AM   #3
Rivet Master
AnnArborBob's Avatar
2014 27' FB Eddie Bauer
Chelsea , Michigan
Join Date: May 2010
Posts: 1,792
Images: 12
Originally Posted by azflycaster View Post
The 14.1 was not the battery, but the output of the charger. Fully charged is around 12.6-12.8, so 12.5 is pretty close (90%) plus there could be a small inaccuracy in your measuring device.
All the above is 100% correct. It will take the battery a couple of hours after you take off the charger to stabilize and for the voltmeter to show 12.7 volts (i.e., fully charged.)

If you put the batteries into "store mode" the only parasitic load you will have on them is the propane detector which will slowly discharge the batteries over a several week period. If you want, you can disconnect the battery cables entirely from the trailer to save yourself even that small discharge.

Keep an eye on your battery voltage when the trailer is in storage and so long as it stays above 12 volts or so you will be fine. There really is no need to keep a trickle charger on the batteries at all times. Obviously you'll want to charge up the batteries up to 12.7 volts before you take the trailer out camping.

Eventually, you'll probably want to consider some kind of solar set up. They range from fairly simple/inexpensive trickle chargers costing a few hundred dollars all the way up to $10,000+ systems for extensive boon docking with little compromise in electricity usage.

I see that you are a newbie, so I would caution you to use your trailer for awhile until you see what you really need based on how you use it before you start making major modifications.

Have fun!
Bob Martel
WBCCI# 5766
AnnArborBob is offline   Reply With Quote
Old 01-31-2015, 12:49 PM   #4

2003 25' Classic
Zanadude Nebula , Milky Way
Join Date: Jun 2007
Posts: 13,167
Images: 1
Thumbs up Charging with the BT...

I use a Battery Tender on our Suburban tow vehicle during the Winter. It doesn't get used very much and the parasitic draw will kill the batt in about 8-10 days.

With the BT connected and the TV battery at 12.2v, it may take up to 2+ days for the green light to come on. 750ma takes some time to overcome the parasitic draw.

Your connection method will work, charging both at once will take longer.
If our Lifelines need to be charged during storage I do them separately. (out of the AS), on a Vector DSC charger.

ROBERT CROSS is offline   Reply With Quote
Old 01-31-2015, 12:53 PM   #5
Rivet Master
1974 Argosy 20
2014 20' Flying Cloud
Kooskia , Idaho
Join Date: Jul 2009
Posts: 4,591
Charge the batteries as you have done but prior to leaving disconnect the negative or positive battery cable (s) and walk away. You will have no problems for months of storage that way. If the batteries are good to begin with, and fully charged of course.

1. Fully charge batteries
2. Disconnect batteries (not just turn the use/store switch off)
3. Enjoy life until you return.
4. When returning, re connect battery.
5. Enjoy
idroba 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
Keeping batteries charged Daysailer Batteries, Univolts, Converters & Inverters 28 04-19-2012 01:02 PM
Batteries say charged but nothing works OKJerry Flat-Front (Cutter, Clipper, XC, XL & Skydeck) Motorhomes 6 06-12-2011 07:03 AM
Are my batteries being charged? Bobdes Electrical - Systems, Generators, Batteries & Solar 13 12-23-2009 06:47 PM
Can't get batteries charged -- why not? neil ervin Batteries, Univolts, Converters & Inverters 23 11-14-2004 07:24 PM

Featured Campgrounds

Reviews provided by


This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:24 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.