Reply
 
Thread Tools Search this Thread Display Modes
 
Old 09-27-2015, 09:21 AM   #1
3 Rivet Member
 
Dalwyn's Avatar

 
2015 Interstate Grand Tour
Southaven , Mississippi
Join Date: Apr 2015
Posts: 233
Unhappy 2015 Grand Tour Ext bad batteries?

How do you determine if coach batteries are bad?

These are the stock batteries (AGM 24) and I think they may have been bad when I purchased the unit. I ran a test last night to try and determine if I could overnight with just the fridge and freezer running and nothing else running other than what draw occurs from items that can't be turned off. I unplugged the unit at 9pm and then checked this morning at 7am, batteries were drained. I know that you aren't suppose to go below 50% but I didn't know how else to test. I tested with the unit in the garage, temperature was approx 70 degrees and down to 66 overnight.

Am I expecting to much for the batteries to run the fridge and freezer overnight?
__________________

__________________
Dalwyn is offline   Reply With Quote
Old 09-27-2015, 09:49 AM   #2
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,311
Quote:
Originally Posted by Dalwyn View Post
How do you determine if coach batteries are bad?

These are the stock batteries (AGM 24) and I think they may have been bad when I purchased the unit. I ran a test last night to try and determine if I could overnight with just the fridge and freezer running and nothing else running other than what draw occurs from items that can't be turned off. I unplugged the unit at 9pm and then checked this morning at 7am, batteries were drained. I know that you aren't suppose to go below 50% but I didn't know how else to test. I tested with the unit in the garage, temperature was approx 70 degrees and down to 66 overnight.

Am I expecting to much for the batteries to run the fridge and freezer overnight?
A single-door Nova Kool refrigerator draws about 2.4 amps. A single-door Nova Kool freezer draws 4.4 amps. Together they draw 6.8 amps. Those of us without Grand Tours only have to deal with a 2.4-amp draw, those with Grand Tour with a 6.8-amp draw.

Two Group 24 house batteries have a total capacity of about 160 amp-hours, so drawing them down to a 50% charge state SHOULD let you use 80 amps. Well, 80 ÷ 6.8 = 11.76 hours. The fridge and freezer cycle on and off, so let's round up to 12 hours for planning purposes. But when initially cooling the units from room temperature, they will be on continuously until they reach the temperature you set on the thermostat and they can cycle off for the first time.

If the fridge and freezer were the ONLY load on the house batteries, you'd get about 12 hours of run time before you had to recharge the house batteries. With the parasitic draws, you'd get less than 12 hours before your house batteries dropped below 50% charge state. Also, since you were running the units in a garage, and overnight besides, no help at all from the solar panel.

So to answer your question, your batteries may not be bad— or at least they weren't. This appears to be more along the lines of a design flaw. Airstream really should have calculated the loads and sized the batteries accordingly, instead of adding more loads to the Grand Tour and keeping the same two Group 24 batteries used in other Interstates. Really, limiting battery capacity so that you get less than 24 hours off the grid before recharging is necessary means the Grand Tour is the LEAST boondocking-capable Interstate when it SHOULD be the MOST capable.

Wonder if there is room underneath the van for a second battery box, and/or room in the battery box to replace the two Group 24s with two 6-volt batteries in series to give you greater amp-hour capacity?
__________________

__________________
WBCCI #1105
TAC LA-4

My Google-Fu is strong today.
Protagonist is offline   Reply With Quote
Old 09-27-2015, 10:23 AM   #3
3 Rivet Member
 
Dalwyn's Avatar

 
2015 Interstate Grand Tour
Southaven , Mississippi
Join Date: Apr 2015
Posts: 233
Protagonist - Thanks for the great info. I not sure about being able to add a second battery box. Someone suggested that I try and upgrade to a Lifeline GPL31XT. Do you know if the stock batteries are Lifeline?
__________________
Dalwyn is offline   Reply With Quote
Old 09-27-2015, 10:25 AM   #4
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,311
Quote:
Originally Posted by Dalwyn View Post
Protagonist - Thanks for the great info. I not sure about being able to add a second battery box. Someone suggested that I try and upgrade to a Lifeline GPL31XT. Do you know if the stock batteries are Lifeline?
Pretty sure they are.
__________________
WBCCI #1105
TAC LA-4

My Google-Fu is strong today.
Protagonist is offline   Reply With Quote
Old 09-27-2015, 11:33 AM   #5
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,279
2015 Grand Tour Ext bad batteries?

Stock AI batteries are usually Lifeline GPL-24T. I typically remove the battery box structure and install a pair of GPL-6CT golf cart batteries at 300! amp/hours. The GPL-31XT should also fit if you want to stay with 12VDC batteries.

I don't advise splitting battery locations, as it will create a problem with the battery temp. sensor if some are inside and others are outside.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Old 09-27-2015, 12:13 PM   #6
Rivet Master
 
2014 Interstate Coach
Arroyo Grande & Central Point , California & Oregon
Join Date: Sep 2011
Posts: 529
What do you think of the Lifeline GPL 4CT's Lew. They will easily fit the OEM battery box.
Bill
__________________
c21bill is offline   Reply With Quote
Old 09-27-2015, 11:06 PM   #7
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,279
Quote:
Originally Posted by c21bill View Post
What do you think of the Lifeline GPL 4CT's Lew. They will easily fit the OEM battery box.
Bill
Just as good as the GPL-6CTs.....only shorter with 220 amp/hours rather than 300.
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Old 09-28-2015, 07:10 AM   #8
Rivet Master
 
Currently Looking...
Nowhere , Somewhere
Join Date: Jul 2005
Posts: 6,417
Blog Entries: 2
Lewis, thanks for the info on separating the batterys. Makes sense. Never thought there could be a problem.
__________________
avionstream is offline   Reply With Quote
Old 09-28-2015, 07:26 AM   #9
3 Rivet Member
 
Dalwyn's Avatar

 
2015 Interstate Grand Tour
Southaven , Mississippi
Join Date: Apr 2015
Posts: 233
Quote:
Originally Posted by lewster View Post
Stock AI batteries are usually Lifeline GPL-24T. I typically remove the battery box structure and install a pair of GPL-6CT golf cart batteries at 300! amp/hours.
Are there any issues in using 6volt vs 12volt if I switch to the GPL-6CT? Anything else that needs to be changed or do I just remove old and install new? Does the battery box structure need to be changed or will what's there work?
__________________
Dalwyn is offline   Reply With Quote
Old 09-28-2015, 08:00 AM   #10
3 Rivet Member
 
Dalwyn's Avatar

 
2015 Interstate Grand Tour
Southaven , Mississippi
Join Date: Apr 2015
Posts: 233
Also, one other question. How long does it normally take for the house batteries to completely charge? I leave my unit plugged in to 30amp outlet all day and when I unplug the monitor only reflects 80% charge. Am I hurting the batteries by leaving the unit plugged in all the time?

Sorry for all the newbie questions, still learning.

Thanks
__________________
Dalwyn is offline   Reply With Quote
Old 09-28-2015, 09:13 AM   #11
4 Rivet Member
 
toskeysam's Avatar
 
2013 Interstate Coach
Townsend , Tennessee
Join Date: Nov 2013
Posts: 487
Re: 6 volt swap....your 12 volt batteries are wired in parallel. You would need to re-wire the 6 volt in series to get 12 volt service. If you have a Magnum charger in the Grand Tour (I think you do) continuous plug-in is not damaging....quite the contrary....it is recommended. IMHO
__________________
FMCA # 436814
toskeysam is offline   Reply With Quote
Old 09-28-2015, 09:29 AM   #12
Rivet Master
 
Boxster1971's Avatar

 
2013 Interstate Coach
Fulton , Maryland
Join Date: May 2010
Posts: 2,265
The OP has a Grand Tour model. The batteries are mounted under the van in rear roadside corner. Not sure those brackets will work with a different battery.
Click image for larger version

Name:	ImageUploadedByAirstream Forums1443450584.511015.jpg
Views:	792
Size:	97.7 KB
ID:	249209


- - Mike
2013 Interstate Lounge EXT on 2012 Sprinter
__________________
- - Mike
--------------------------
2013 Airstream Interstate Lounge EXT
Boxster1971 is offline   Reply With Quote
Old 09-28-2015, 10:21 AM   #13
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,279
Quote:
Originally Posted by Dalwyn View Post
Also, one other question. How long does it normally take for the house batteries to completely charge? I leave my unit plugged in to 30amp outlet all day and when I unplug the monitor only reflects 80% charge. Am I hurting the batteries by leaving the unit plugged in all the time?

Sorry for all the newbie questions, still learning.

Thanks
Your Magnum MMS-1012 inverter/charger has an integrated 50 amp charging section. you should see 100% charge over an entire day. I always use a Magnum ME-RC programmable remote when I do a Magnum install or upgrade. This gives you far ore capabilities than the ME-MR that Airstream installs.

If your batteries are drawn to 50% and you have the stock group 24 batteries, that means that you have to replace 80 amp/hours of charge. With a 50 amp charger, that should take less than 2 hours when plugged in and utilizing the Magnum. Sounds like something is not set correctly in the Magnum........which wouldn't surprise me at all.

I wold suggest doing the monitor upgrade and also adding their temperature sensor if they have not included one. This is especially important now that they have moved their batteries outside!!
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Old 09-28-2015, 10:57 AM   #14
Rivet Master
 
UKDUDE's Avatar
 
2014 Interstate Ext. Coach
Sedona , Arizona
Join Date: Jul 2008
Posts: 1,038
Quote:
Originally Posted by lewster View Post
Sounds like something is not set correctly in the Magnum........which wouldn't surprise me at all.D

I have a 2 page Magnum Settings PDF sent to me by Airstream. Haven't found a way to include it here using my iPad which I'm using while on a trip, but I can email it to anyone on request.



Sent from my iPad using Airstream Forums
__________________

__________________
UKDUDE is offline   Reply With Quote
Reply


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
Interstate Grand Tour EXT Twin Floor Plan TOdehnal Sprinter and B-van Forum 8 07-28-2015 07:18 PM
2015 Airstream Interstate Grand Tour EXT 24 - Florida ineed2golf Airstream Classifieds 0 04-14-2015 08:00 AM
First trip in our new 2015 Interstate Grand Tour LizabethLane Sprinter and B-van Forum 40 10-29-2014 03:06 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:38 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

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