Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-25-2005, 07:52 PM   #1
Rivet Master
 
MarkR's Avatar
 
1951 21' Flying Cloud
1960 24' Tradewind
Folsom , California
Join Date: Dec 2003
Posts: 725
Images: 12
sizing a converter

Hi,
I need to start from scratch on wiring my trailer and am wondering how to pick an amperage for a converter. I'm assuming you add up all the "stuff" that will need 12v power and that gives you a size, just don't know what "values" to use for each item or if there's a "rule of thumb". Anyway, I'm looking at an Inteli Power 9100 and they come in 30, 40, 45, 60, 80 . . . amp sizes and I want to "choose wisely" (and I did do a search and found lots of good information, but never found a thread on how to pick the right size). Thanks in advance for your help.
Mark
__________________

__________________

Aluminumbskull with Led Balloon in Drag
***
Birch Plywood and Aluminum go together like
Peanut Butter and Chocolate
MarkR is offline   Reply With Quote
Old 05-25-2005, 08:04 PM   #2
Rivet Master
 
till's Avatar
 
Lisle , Illinois
Join Date: Nov 2003
Posts: 1,270
Images: 108
Blog Entries: 2
What size is you coach?? That will help give you a starting point. A lot of the mid-size coaches seem to be picking the 60 amp unit from what I have read. What size was the old one??
__________________

__________________
Tedd Ill
AIR#3788 TAC IL-10
1967/8 Overlander International Twin w/ bunk/s.
Yes, four kids and two adults in the thing.
Happy wife, happy life.
till is offline   Reply With Quote
Old 05-25-2005, 08:06 PM   #3
Rivet Master
 
MarkR's Avatar
 
1951 21' Flying Cloud
1960 24' Tradewind
Folsom , California
Join Date: Dec 2003
Posts: 725
Images: 12
21ft 1951-ish Flying Cloud . . . and there wasn't one previously.
And yes it seems like 60 seems to be popular and probably a safe choice, I just want to know why, thanks.
__________________

Aluminumbskull with Led Balloon in Drag
***
Birch Plywood and Aluminum go together like
Peanut Butter and Chocolate
MarkR is offline   Reply With Quote
Old 05-25-2005, 08:22 PM   #4
Rivet Master
 
LOST , Hawaii
Join Date: Jun 2002
Posts: 2,193
How will you use this? Boondocking with a couple of batteries, mostly on an electric site? Battery charging will take more power than running lights, etc., I would decide on the use and size the converter accordingly. 60 amp will recharge a couple of batteries fairly quickly but would be overkill if you had 1 battery and used hookups most of the time.

John
__________________
74Argosy24MH is offline   Reply With Quote
Old 05-25-2005, 08:51 PM   #5
Rivet Master
 
MarkR's Avatar
 
1951 21' Flying Cloud
1960 24' Tradewind
Folsom , California
Join Date: Dec 2003
Posts: 725
Images: 12
I'm not an electrician and I don't even play one on TV . . . And I haven't had a working trailer before so I don't for sure know what I want/need as far as "power" options.
I'm going to guess that we'll do both "boondocking" and be "hooked-up" . . . But isn't the converter like the panel in your house - sized for the load you will create? So if I'm hooked up for a few days somewhere don't I need a converter with enough amps to power my lights and small appliances (assuming my battery(s) is charged up and not "drawing" on the converter? And isn't that how you would choose a size?
Thanks, for helping.
Mark
__________________

Aluminumbskull with Led Balloon in Drag
***
Birch Plywood and Aluminum go together like
Peanut Butter and Chocolate
MarkR is offline   Reply With Quote
Old 05-25-2005, 09:41 PM   #6
Just a member
 
thenewkid64's Avatar
 
1978 28' Argosy 28
Tampa Bay , Florida
Join Date: Mar 2002
Posts: 4,539
Images: 21
Send a message via AIM to thenewkid64 Send a message via Yahoo to thenewkid64 Send a message via Skype™ to thenewkid64
I would size it based on number of batteries you plan to recharge.

Bigger means faster recharge. Most of the group 27 batteries are 105 Amp Hour batteries. If you draw 2 down 50% then you need to charge for 2 hours at 50 amps to theoretically recharge them. A 60 amp should be fine unless you plan on lighting every thing off at once.
__________________
Brett G
WBCCI #5501 AIR # 49
-------------------------
1978 Argosy 28 foot Motorhome

Wise men talk because they have something to say; fools, because they have to say something. -- Plato


thenewkid64 is offline   Reply With Quote
Old 05-25-2005, 09:54 PM   #7
Rivet Master
 
LOST , Hawaii
Join Date: Jun 2002
Posts: 2,193
Phrannie.org

Good reading about everything rv.

I am going to assume your small appliances will run off of 120v so they won't have any draw from the converter. If they have a relatively low draw you can run them off an inverter, but it will really put a dent in your batteries quickly. TV, dvd, are ok, microwave, coffepot, are killers.

If you boondock for more than a couple of days 1 battery probably won't make it. If it is cool and you use the furnace it definitely won't. 60 amp is a good choice for a quick charge with dual batteries, 45 will do it just in a longer time. But unless you are limited in the amount of time you are hooked up it won't matter that much.

When you are hooked up and have a heavy draw the battery and converter will both contribute power. When the draw is over the converter goes back to charging. You can have some fairly heavy loads that way, more than the converter alone is capable of supplying. Without using an inverter it would be hard to draw 45 amps, that is a lot of power at one time for an rv.

The batteries and how quickly you want to charge them are really what you should look at when sizing the converter. Coming off a few days boondocking will put a lot more load on it than normal useage while hooked up.

John
__________________
74Argosy24MH is offline   Reply With Quote
Old 05-25-2005, 10:06 PM   #8
Site Team
 
, Minnesota
Join Date: Aug 2003
Posts: 6,940
Images: 59
Mark,

It's correct that you should first size the batteries, then pick a converter based on the battery size.

You need to use a little caution if you plan to use 40 amps or more to charge the batteries. Some batteries (especially gel batteries) can't absorb that much energy.

AGM batteries would be ok. And get the charge wizard to keep your batteries from overheating.
__________________
markdoane is offline   Reply With Quote
Old 05-25-2005, 10:44 PM   #9
Rivet Master
 
Over59's Avatar
 
1959 26' Overlander
Putnam , Connecticut
Join Date: Sep 2003
Posts: 3,064
Images: 37
Looks like you have your answer. I would add that laying the whole thing out will save time and money and redoing. Do you really need any AC appliances. The only thing that comes to mind that's not available in DC are hair dryer and microwave. If you run a fridge on DC that's alot of juice. I suspect you will be needing a heater and there are some low amp heaters out there (to run the fan). Two 27's should be fine. They are heavy so you won't want more without a good reason. Research the threads for batteries as there is lots of info on manufacture dates ect. Get two the same.

What's the condition of the Cloud?
__________________
Over59 is offline   Reply With Quote
Old 05-26-2005, 12:24 AM   #10
Rivet Master
 
2005 22' International CCD
Buckhorn , Ontario
Join Date: Jan 2004
Posts: 2,773
Images: 59
Blog Entries: 5
Send a message via Skype™ to GT1963
Being boaters we are more familiar with deep cycle marine batteries - which we have come to understand is very similar to that of the battery we now have for the trailer.

We have been under the impression and were advised that both deep cycle batteries should be recharged at a slow rate to prolong their life. We were going to get the 60 amp and then discussed the differences with Airstream Inc as well as the our Ontario Dealer - we had an original 30amp system in the Trailer and were not adding anything different - we were strongly advised that we do not push the system above the 40amp converter as the trailer was not wired for it.

It made sense and we think it was good advice - as we were not changing or upgrading the wiring nor adding anything to the system. We do however have the charge wizard and it works great.
__________________
Everything will be alright in the end. If it is not alright now, then it is not the end.
GT1963 is offline   Reply With Quote
Old 05-26-2005, 01:09 PM   #11
Well Preserved

 
1993 21' Sovereign
Colfax , North Carolina
Join Date: Jun 2003
Posts: 20,190
Quote:
Originally Posted by Over59
The only thing that comes to mind that's not available in DC are hair dryer and microwave.
And we have a 12v hair dryer. It is not a powerhouse of hot air, but it gets the job done.
__________________

__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
overlander63 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
Why use a converter? PatCrusse Electrical - Systems, Generators, Batteries & Solar 2 11-27-2002 07:52 AM
Converter Breaker? Sav'h Steve Electrical - Systems, Generators, Batteries & Solar 7 11-18-2002 09:45 AM
Converter relocation FrankR Batteries, Univolts, Converters & Inverters 0 07-31-2002 09:30 AM
Converter box floor mount FrankR Electrical - Systems, Generators, Batteries & Solar 0 03-27-2002 11:34 PM
Converter box for into floor mount FrankR Electrical - Systems, Generators, Batteries & Solar 0 03-15-2002 10:49 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:19 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.