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
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, WBCCI#4028 Membership discontinued
1967/8 Overlander International Twin w/ bunk/s.
Yes, four kids and two adults in the thing.
Happy wife, happy life.
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.
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.
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
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
"Stop worrying about the potholes in the road and celebrate the journey." -- Fitzhugh Mullan
Wise men talk because they have someting to say; fools, because they have to say something. -- Plato
In politics, absurdity is not a handicap— Napoleon
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.
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.
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?
__________________ Let those who can play, let those who cann't rule.
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.
__________________ Streaming in the spirit of Exploration... "To go places and do things that have never
been done before-that's what living is all about." - M. Collins
Quick Links
Linear Mode
