Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-08-2015, 08:05 AM   #1
2 Rivet Member
 
easler7267's Avatar
 
2015 25' FB Flying Cloud
Hanscom AFB , Massachusetts
Join Date: Mar 2015
Posts: 32
Electrical usage

I have what is probably a real newbie question but would appreciate some education on our electronics system. My wife & I just did our first boondocking trip for 4 days. At the beginning our batteries were fully charged at 12.6 V (according to the display panel in the AS). We were pretty frugal for the 4 days: we used the water pump for showers, toilet & washing dishes. Ran the fridge & hot water heater on propane, so I believe that uses power (minimal) for the 12V control boards to start them on propane when necessary. We didn't use TV or radio and were very minimal on our LED lights (only when using the bathroom).

After the 4 days our batteries were at 11.4V.

My question is probably a basic electronics question:

How low could our voltage have gone before things didn't work anymore? Is the voltage something like a gas tank where we could run it to 0? Or is there a certain amount below 12 volts where the control boards for the hot water heater & fridge will experience brownouts & not work anymore? Is there a certain level where we might damage equipment by allowing voltage to go too low.

Thanks in advance for any help/education!


Sent from my iPhone using Airstream Forums
__________________

__________________
easler7267 is offline   Reply With Quote
Old 06-08-2015, 08:18 AM   #2
Rivet Master
 
lsbrodsky's Avatar
 
2012 25' FB International
Trent Woods , North Carolina
Join Date: May 2013
Posts: 1,687
Well, grasshopper, you have much to learn about batteries. Basically you never want to drop your batteries below 50% capacity, which is approximately 12.2 volts. If you do, you reduce the capacity of the batteries permanently or almost permanently, in so far as normal charging is concerned. You seemed to have completely discharged your batteries, much longer and things would have stopped working. They will recharge but the amount of amp-hours you get out of them to 50% will no be less than before.
There are many places on this forum and the internet that talk about battery discharging and recharging. You need to get yourself solar or a small generator if you plan to camp without AC power for 4 days, just to charge your batteries.

Larry
__________________

__________________
lsbrodsky is offline   Reply With Quote
Old 06-08-2015, 08:22 AM   #3
2 Rivet Member
 
easler7267's Avatar
 
2015 25' FB Flying Cloud
Hanscom AFB , Massachusetts
Join Date: Mar 2015
Posts: 32
Thanks Larry. Can you explain the math there: a drop from 12.6 to 11.4 equals 50% discharge? I'd like to understand that better for future predictions of power usage.


Sent from my iPhone using Airstream Forums
__________________
easler7267 is offline   Reply With Quote
Old 06-08-2015, 09:17 AM   #4
Rivet Master
 
lsbrodsky's Avatar
 
2012 25' FB International
Trent Woods , North Carolina
Join Date: May 2013
Posts: 1,687
There is no math. Go to Google and search on "12 v battery state of charge". You will see tables that give you voltage and state of charge. Batteries are just made up of individual cells with a chemical reaction going on. My basic chemistry was many eons ago but I do not remember it being linear, more asymptotic.
Larry
__________________
lsbrodsky is offline   Reply With Quote
Old 06-08-2015, 09:30 AM   #5
3 Rivet Member
 
grizbear's Avatar
 
2004 25' Safari
Crestview , Florida
Join Date: Oct 2014
Posts: 162
Battery ?'s

A fully charged battery will be in the range of 12.7 to 12.9 volts after charging and resting a few hrs. They should not be discharged to less than 12.15 or there will be damage done they should also be charged ASAP after discharge to prevent damage. It only takes one or two times to damage a battery. If you have a standard converter/charger its does a very poor job of charging the batteries I upgraded to a Progressive Dynamics PD4655 a three stage charger.
Before that I used a portable three stage charger. There is a lot of battery info on battery company sites like Trojan or Interstate. Worth a look. Good camping
Rand
__________________
grizbear is offline   Reply With Quote
Old 06-08-2015, 10:25 AM   #6
3 Rivet Member
 
ckottum's Avatar
 
2012 25' Flying Cloud
Battle Lake , Minnesota
Join Date: Mar 2015
Posts: 231
If boondocking for several days, you probably should consider a (quiet) generator, or (adequate to your power use) solar system with more battery storage capacity) for keeping your batteries charged. The factory batteries without a recharging system is very limiting without external power hookups.
__________________
ckottum is offline   Reply With Quote
Old 06-08-2015, 10:56 AM   #7
Rivet Master
 
1974 Argosy 20
2014 20' Flying Cloud
Kooskia , Idaho
Join Date: Jul 2009
Posts: 4,591
The two batteries in your Airstream have a capacity of about 75 amp hours each, or 150 amp hours total. An amp hour is just what it sounds like, one amp used for one hour.

It is best not to discharge the batteries lower than 50%, so a total of 75 amp hours is what it would be best to work with, although occasional use down to 25% is not the end of the world, but will shorten the life of the batteries considerably. Total discharge, and especially without immediate recharge will damage the batteries very rapidly.

It is not uncommon for batteries in new rigs, left on the lot with no recharge to be damaged when you buy it, especially if it has been a lot demonstrator for several months.

Back to your batteries. Over 4 days or 96 hours you could at best (or worst) use a total of 150 amp hours if you allowed the batteries to discharge completely.. again, not a good idea at all. This also assumes that the batteries were fully charged to begin with, and that would mean the rig was plugged into line power for at least 24 hours prior to your trip. The battery monitor system is not very accurate to determine full charge.

So, 96 hours and 150 amp hours means that your total load on average over those 96 hours could be 150/96 = 1.56 amps. The refrigerator alone (assuming it does not have a fan, I am not sure about the 25' ones, my 20' has a fan) usually takes in the range of 0.5 amps to 0.8 amps alone. If you have a fan in the external refrigerator compartment, it will take another 0.5 amps when it is running. The water heater, when the burner is running takes about 0.75 amps. (none when the burner is not on). Add to those numbers the pump (minimal use, so not a big load) and some lights and you can see how fast you can add to your load. Remember, only 1.56 amps average is all you could draw, and that assumes full charge to begin with and allowing total discharge at the end.

Most people find that about 2 days is all they can go without a battery recharge, and less in cold weather when they use the furnace. Consider a generator or a solar package for longer times boondocking.
__________________
idroba is offline   Reply With Quote
Old 06-08-2015, 11:09 AM   #8
Rivet Master
 
AnnArborBob's Avatar
 
2014 27' FB Eddie Bauer
Chelsea , Michigan
Join Date: May 2010
Posts: 1,767
Images: 12
In my opinion, the basic battery and charging system supplied by Airstream is adequate for an occasional one or two nights without electrical hooks ups or to get you from one campsite with electrical hookups to the next.

If you want to boon dock for more than 48 hours, you will need to beef up your batteries and/or get some solar panels and/or generator (preferably the quiet inverter type.)

Use the "search function" on this forum to finds lots of threads on the subjects of boon docking, solar, generators, batteries, etc...

Happy camping!
__________________
Bob Martel
WBCCI# 5766
AnnArborBob is offline   Reply With Quote
Old 06-08-2015, 12:07 PM   #9
Rivet Master
 
2016 30' Classic
Erie , Colorado
Join Date: Oct 2013
Posts: 1,245
Images: 1
Here's a battery table.

Click image for larger version

Name:	Battery Charge level.png
Views:	272
Size:	63.1 KB
ID:	240254
__________________
Gary
2015 Classic
2015 GMC Sierra 2500HD Duramax
ProPride
NVPN
ghaynes755 is offline   Reply With Quote
Old 06-08-2015, 12:12 PM   #10
Rivet Master
 
aftermath's Avatar
 
2006 25' Safari FB SE
Spokane , Washington
Join Date: Sep 2009
Posts: 1,133
Here is a link to the 12 Volt Side of Life. It has a lot of good information.

The 12volt Side of Life (Part 1)

Read up on the proper way to charge batteries. I do not know what kind of inverter/chargers the newer Airstreams come with but you might want to check and see if it is a 3 stage charger. I have a 2006 purchased in 2009 and the PO left it plugged in 24/7 for all three years. He was a contractor and would take it out to job sites where he would plug it in. When we looked at it, it was plugged in and everything worked. I never looked at the batteries. On our trip home we stayed over night at an RV Park and plugged it it there too! On our first trail outing the batteries lasted for just a few hours. They were completely dry.

A single stage charger will charge your batteries and then continue to charge them until they get hot, the solution in the cells boil off and the battery is no longer of any use. Have the charger checked. I replaced mine with an IOTA and it was not real expensive.
__________________
aftermath is offline   Reply With Quote
Old 06-08-2015, 12:16 PM   #11
3 Rivet Member
 
2015 16' Sport
Portland , Oregon
Join Date: May 2015
Posts: 144
The OP has a 2015. They come with a 3 stage charger. At least mine did
__________________
leedav is offline   Reply With Quote
Old 06-08-2015, 12:17 PM   #12
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,408
Images: 5
The Interstate chart says 12.06V is 50%. Charts differ in their values. I have used 12.06V as my bogie, and my batts are almost 4 years old. I just completed an Ah drain test, and I am happy to report no degradation of capacity. Obviously, there is more charging/monitoring equipment in my case, which helps, but 12.06 is a good value, IMO.
__________________
-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 06-08-2015, 12:20 PM   #13
3 Rivet Member
 
2015 16' Sport
Portland , Oregon
Join Date: May 2015
Posts: 144
My batts were around 12v after two days without external power. Now the propane powered Honda 2000 is in da house, so I'll be recharging during the day. Gasoline was not an option because I did not want to travel with gasoline in the Yukon
__________________
leedav is offline   Reply With Quote
Old 06-08-2015, 12:25 PM   #14
4 Rivet Member
 
jayseejay's Avatar
 
2015 27' FB Eddie Bauer
2011 25' FB Flying Cloud
Fernandina Beach , Florida
Join Date: Sep 2013
Posts: 489
Quote:
Originally Posted by leedav View Post
The OP has a 2015. They come with a 3 stage charger. At least mine did

It is interesting to hear that some 2015s came with a three stage charger. My 2015 came with a single stage charger. At the time of order, I asked if a three stage charger could be installed as a option, and I was told that was not available. Joe
__________________

__________________
jayseejay 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
Olympic rivet shaver usage airstream4 Ribs, Skins & Rivets 3 05-15-2006 08:37 AM
How to modify toilet for long term fixed usage? haynes Waste Systems, Tanks & Totes 0 05-26-2004 05:31 AM
Propane Usage Report Pick LP Gas, Piping, Tanks & Regulators 2 02-25-2004 05:47 PM
Propane Usage COArgosy78 On The Road... 6 02-25-2003 10:35 PM
Airstream Forum Blues-suggestions for forum usage hex Our Community 18 10-20-2002 12:12 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:10 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.