Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-23-2014, 03:12 PM   #1
1 Rivet Member
 
Lnob's Avatar
 
2014 27' FB Eddie Bauer
Bell Canyon , California
Join Date: Oct 2013
Posts: 10
New Batteries

Hi there
I just bought 2 new Interstate SRM24 batteries. When I first put them in the monitor read 12.5.
I charged overnight from 110V now reads 12.8. I recall when I first got the AS that after charging I could be at 13.4ish. When I called the place where I purchased them he says 12.8 is what it should read. Can somebody please explain. I'm confused.
I also store it where I was leaving it plugged into 110v. After searching here i now realize i shouldn't do that. Maybe that's why the other batteries died after a year?
Thank you in advance
Laura
__________________

__________________
Lnob is offline   Reply With Quote
Old 10-23-2014, 04:03 PM   #2
Rivet Master
 
daveswenson's Avatar
 
2012 28' International
Issaquah , Washington
Join Date: Sep 2012
Posts: 767
Here's a chart of typical voltages for a flooded lead battery.

State of Charge 12 Volt battery Volts per Cell
100% 12.7 2.12
90% 12.5 2.08
80% 12.42 2.07
70% 12.32 2.05
60% 12.20 2.03
50% 12.06 2.01
40% 11.9 1.98
30% 11.75 1.96
20% 11.58 1.93
10% 11.31 1.89
0 10.5 1.75

As far as leaving it plugged in, if you have the Parallax charger that comes standard you are right. It is a one stage charger and will kill your batteries.
__________________

__________________
Dave

2014 Ram 2500 CTD
Pro Pride
Centramatics
daveswenson is offline   Reply With Quote
Old 10-23-2014, 04:09 PM   #3
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,281
Quote:
Originally Posted by daveswenson View Post
Here's a chart of typical voltages for a flooded lead battery.

State of Charge 12 Volt battery Volts per Cell
100% 12.7 2.12
90% 12.5 2.08
80% 12.42 2.07
70% 12.32 2.05
60% 12.20 2.03
50% 12.06 2.01
40% 11.9 1.98
30% 11.75 1.96
20% 11.58 1.93
10% 11.31 1.89
0 10.5 1.75

As far as leaving it plugged in, if you have the Parallax charger that comes standard you are right. It is a one stage charger and will kill your batteries.
Your numbers are pretty low for most batteries that I have seen. Where did you get the information? Typically, 12.8-13.2 is considered 100% and 12.2 is 50% discharged.
__________________
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 10-23-2014, 04:20 PM   #4
Rivet Master
 
daveswenson's Avatar
 
2012 28' International
Issaquah , Washington
Join Date: Sep 2012
Posts: 767
Hi Lew,
I got those numbers here.

Deep Cycle Battery FAQ

I thought they sounded a little low. I was too lazy to search further.
__________________
Dave

2014 Ram 2500 CTD
Pro Pride
Centramatics
daveswenson is offline   Reply With Quote
Old 10-23-2014, 05:37 PM   #5
Rivet Master
 
weirdstuff's Avatar
 
2018 23' International
Currently Looking...
San Diego , California
Join Date: Oct 2013
Posts: 1,070
Lew, do you have, or can you post a similar chart of what you think these numbers are? This would be very helpful.

After having ours in indoor storage, unplugged for 1.5 weeks, the house batteries read 12.5, and the chassis battery was around 12.3.

(We're trying to figure out how long we can safely leave her alone in storage)

Thanks!
weirdstuff is offline   Reply With Quote
Old 10-23-2014, 05:54 PM   #6
TinCan
 
graysailor's Avatar

 
2016 30' Classic
Apache Junction , Arizona
Join Date: Aug 2011
Posts: 798
Go with a 3 stage smart charger and most of your battery problems will solved.
__________________
TinCan
graysailor is offline   Reply With Quote
Old 10-23-2014, 06:35 PM   #7
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,408
Images: 5
Dave's chart is what I have seen for regular old fashioned Lead acid batteries (automotive and deep cycle) from many sources and my personal professional experience for decades. I've never seen a fully charged resting LA battery at 12.8 - 13.2 in a resting state. (after several hours minimum resting)

I have seen some minor variations in the scale, but I use 12.06 as my 50% level. Some say 12.1 is 50% and some say 12.0 is 50%.
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is offline   Reply With Quote
Old 10-23-2014, 07:37 PM   #8
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,281
Quote:
Originally Posted by weirdstuff View Post
Lew, do you have, or can you post a similar chart of what you think these numbers are? This would be very helpful.

After having ours in indoor storage, unplugged for 1.5 weeks, the house batteries read 12.5, and the chassis battery was around 12.3.

(We're trying to figure out how long we can safely leave her alone in storage)

Thanks!
AGMs in general and Lifelines in particular have higher voltages due to their much lower internal resistance. Here is a chart from the Lifeline owners manual:


State of Charge 2 Volt Battery 6 VoltBattery 12 VoltBattery
100% 2.16V or more 6.50V or more 12.8V or more
75% 2.08V 6.25V 12.5V
50% 2.03V 6.10V 12.2V
25% 1.98V 5.95V 11.9V
0% 1.93V or less 5.8V or less 11.6V or less

The most important take-away from this 12.8-13.2VDC is 100%, 12.2VDC is 50% and 11.6VDC is 0 % for Lifelines

I would use the 12.2 VDC as a bottom level for storage and would re-charge them when they hit that voltage.
__________________
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 10-23-2014, 07:39 PM   #9
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,408
Images: 5
Yup, I was aware that AGMs do generally have higher voltages than Lead acid.
__________________

__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g 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
1992 Airstream B 190 118,000 miles new tires, alternator, 2 new batteries. eBay Watch Airstreams on eBay 0 07-29-2013 08:50 AM
2 batteries outside and two batteries inside timmaah Electrical - Systems, Generators, Batteries & Solar 14 08-25-2011 08:18 AM
Batteries Short...New Converter robandzoe Electrical - Systems, Generators, Batteries & Solar 25 03-22-2005 12:38 PM
Batteries..All about batteries FrankR Batteries, Univolts, Converters & Inverters 0 07-17-2002 10:05 PM
Where should I install new batteries? Andy R Electrical - Systems, Generators, Batteries & Solar 3 03-31-2002 11:01 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:56 PM.


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.