Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 05-30-2014, 10:42 AM   #1
Senior Member
 
ardbark's Avatar
 
Monaco Owners Club
Join Date: Oct 2011
Location: Logan, Ut
Posts: 315
Right sizing inverter

I'm finally getting around to adding an inverter and want to make sure I match the Inverter size to the house battery pack.

I've got my eye on the Xantrex PROWatt SW series, it seems to be the favorite of lots of veteran RV'ers. It's a pure sine wave model which my computer will enjoy, and comes in several sizes which I have to pick from. Hence my question.

I have two 6v house batteries each rated at 225 amp hours @ 20 hours and 185 AH @ 5 hours. The most load the inverter will see at one time will likely be no more than house lights (all 12v) and a laptop and monitor, or a flat screen TV and DVD player if we're watching TV, maybe a small 110v sound system, awning lights (110v) when we're on the patio, those sort of things. No hair dryers, no residential fridge (although I wouldn't mind keeping that in mind if/when the Norcold finally dies). So no really big loads. If I need AC or the microwave I'll fire up the genny.

I get adding up watts from all the toys and picking an inverter size to match, but is there a formula for matching Inverter watts to rated Amp Hours for the batteries?

cheers...
__________________

__________________
Its not the destination, its the journey
2003 FW Disco 39L chased by 2300 lbs of raging GEO Tracker
ardbark is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 05-30-2014, 11:05 AM   #2
Senior Member
 
Gocoffeer's Avatar
 
Join Date: Feb 2012
Posts: 1,137
ARDBARK: I have just completed an inverter add on project to my rig. I took advice from VSHEETS. He uses several smaller inverters and a whole house model to get a more economical use from his batteries. Let me explain.
Each inverter size and model type that you use has a certain "no load" electrical cost to its use. Smaller inverters have very low non load electrical use. I bought a couple PV375 Tripplite inverters I bought used on Ebay and use these for my TV, blueray and charging the laptops. I also have a chinese made 3000W Pure Sine wave model as a whole house model to use the microwave and run other big appliances. The little inverters are permanently installed as is the big inverter....the little guys can be forgotten and left on if needed while the big guy has real electrical draw overhead and can in a non load situation run the coach batteries down quickly.
I use remote on/off switch to more easily turn the big guy on and off ...the little guys are installing in an easy access area and they can be turned on and off most easily.

there is a formula...I hated it so I offered you this better explained link.

How to Choose a Power Inverter
__________________

__________________
Craig Gosselin
1994 Fleetwood 33H
1995 Fleetwood 30H (parts vehicle)
Gocoffeer is offline   Reply With Quote
Old 05-30-2014, 11:08 AM   #3
Senior Member
 
al2ride's Avatar
 
Join Date: Jan 2014
Posts: 1,278
Check out the Battery Sizing section.
Attached Files
File Type: pdf Prowatt 1500(445-3026-01_rev_1).pdf (732.9 KB, 36 views)
__________________
USAF Veteran
2014 Forest River Georgetown 351DS
2014 Jeep Wrangler Unlimited Rubicon Toad
al2ride is offline   Reply With Quote
Old 05-30-2014, 12:35 PM   #4
Senior Member
 
ardbark's Avatar
 
Monaco Owners Club
Join Date: Oct 2011
Location: Logan, Ut
Posts: 315
Yikes! Be careful of what you ask for I guess. And here I thought I was just going to go out and buy an inverter. Silly me Thanks much, really good information.

With the multiple inverter, small guy/big guy system do you just mount the small guys at the point of attack, i.e. one next to the TV, one next to the PC or whatever, or did you wire them into specific breakers to service only those outlets the TV/PC/whatever are plugged into? Same with the big guy, did you wire him direct into the whole breaker box?

cheers...
__________________
Its not the destination, its the journey
2003 FW Disco 39L chased by 2300 lbs of raging GEO Tracker
ardbark is offline   Reply With Quote
Old 05-30-2014, 12:52 PM   #5
Senior Member
 
PyrateSilly's Avatar
 
Monaco Owners Club
Join Date: Jul 2011
Posts: 2,200
We went ahead and got a 3000 watt pure sine from Xantrex to replace a 1500 modified sine one.

Question - What power does your microwave use? Ours uses 1600 watts ..... when we replaced the old inverter we needed to replace the microwave too. For our coach everything pretty much goes thru the inverter, even if on shore power or genny, which means the old 1500 watt one was trying to get a 1600 watt machine to work. It wasn't that long before we had to replace both, that's why we went with the 3000 watt one. If we ever need more we can always add another one and chain them together since it is designed to that if needed.
__________________
Thom and Christine having fun in a 1993 Monaco Crown Royale Signature Series 40ft 300hp RV. Towing a Fiat 500 Abarth and a Harley.
Our blogged repairs and travels
PyrateSilly is offline   Reply With Quote
Old 05-30-2014, 01:04 PM   #6
Senior Member
 
al2ride's Avatar
 
Join Date: Jan 2014
Posts: 1,278
Quote:
Originally Posted by PyrateSilly View Post
We went ahead and got a 3000 watt pure sine from Xantrex to replace a 1500 modified sine one.

Question - What power does your microwave use? Ours uses 1600 watts ..... when we replaced the old inverter we needed to replace the microwave too. For our coach everything pretty much goes thru the inverter, even if on shore power or genny, which means the old 1500 watt one was trying to get a 1600 watt machine to work. It wasn't that long before we had to replace both, that's why we went with the 3000 watt one. If we ever need more we can always add another one and chain them together since it is designed to that if needed.
I bet it was the modified inverter that jacked up your microwave and not how close you were to max. The inverter would have shut down and throw a code if you pushed it too hard.

The other thing is that what's listed on the appliance labels may not be what they are actually using. I can't remember the exact number, you a member hooked up an amp meter to see what his residential refrigerator was pulling from the inverter. The refrigerator's specifications called for something like 5 amps, and the meter never wen up past 1.5 amps or something like that. That was during normal operation.
__________________
USAF Veteran
2014 Forest River Georgetown 351DS
2014 Jeep Wrangler Unlimited Rubicon Toad
al2ride is offline   Reply With Quote
Old 05-30-2014, 01:38 PM   #7
Senior Member
 
ardbark's Avatar
 
Monaco Owners Club
Join Date: Oct 2011
Location: Logan, Ut
Posts: 315
Quote:
Originally Posted by PyrateSilly View Post
We went ahead and got a 3000 watt pure sine from Xantrex to replace a 1500 modified sine one.

Question - What power does your microwave use? ....
Books are all down to the rig and I don't know off the top of my head on the microwave/convection oven. It's quite a bit though.

I didn't envision running it off the inverter anyway. We're really just looking to be able to work on the computer or watch TV when spending a quick night in Wal-Mart or a rest area, or up a dirt road that looks interesting or whathaveyou. We have no intension of dry camping on BLM for months at a time.

And like I mentioned, I have a big beasty genny that can power a small city if I need to run a table saw in between sightseeing trips
__________________
Its not the destination, its the journey
2003 FW Disco 39L chased by 2300 lbs of raging GEO Tracker
ardbark is offline   Reply With Quote
Old 05-30-2014, 01:46 PM   #8
Senior Member
 
Gocoffeer's Avatar
 
Join Date: Feb 2012
Posts: 1,137
Mounting the small inverters was easy in my case. I had removed the older CRT type TV and had a nice empty cabinet to use as my space. I did the wood work to make use of that space and hide my electrical and hardware. But the PV375 and PV150 TrippLite inverters are the size of handheld radios (4x5.5") ... I went out of the box when it came to wiring all my inverters into the 120v circuits. Bringing battery power to the inverters and hooking them for use was not too complex (wire routing is the tricky part). You use oversized wire for the Battery to Inverter portion to prevent voltage loss. Wait until you see the wire sizing chart for a big inverter install. It gets scary and expensive buying copper in that size.
__________________
Craig Gosselin
1994 Fleetwood 33H
1995 Fleetwood 30H (parts vehicle)
Gocoffeer is offline   Reply With Quote
Old 05-30-2014, 03:51 PM   #9
Senior Member
 
PyrateSilly's Avatar
 
Monaco Owners Club
Join Date: Jul 2011
Posts: 2,200
Quote:
Originally Posted by ardbark View Post
Books are all down to the rig and I don't know off the top of my head on the microwave/convection oven. It's quite a bit though.
I didn't envision running it off the inverter anyway. We're really just looking to be able to work on the computer or watch TV when spending a quick night in Wal-Mart or a rest area, or up a dirt road that looks interesting or whathaveyou. We have no intension of dry camping on BLM for months at a time.
And like I mentioned, I have a big beasty genny that can power a small city if I need to run a table saw in between sightseeing trips
Like I said our coach was built with pretty much everything going thru the inverter. If we have the power go out things will still stay on, there's very little interruption in stuff. If it does go out I will shut a few things off like the ice maker and hot water heater thou until we do have power they are a large power draw on just inverter. So knowing that everything goes thru it we knew that we needed a larger inverter to be able to handle everything pretty much at once and figured why not just go ahead and do pure sine while at it too. Thom does work with electric in his job so he did the take out and install himself. The next thing he is talking adding is a few more solar panels to help with the house batteries and not just the coach battery but that is probably down the line.

This is the way ours was built, yours does not sound like it was built like that thou.
__________________
Thom and Christine having fun in a 1993 Monaco Crown Royale Signature Series 40ft 300hp RV. Towing a Fiat 500 Abarth and a Harley.
Our blogged repairs and travels
PyrateSilly is offline   Reply With Quote
Old 05-30-2014, 03:52 PM   #10
Senior Member
 
wa8yxm's Avatar
 
Damon Owners Club
Workhorse Chassis Owner
Join Date: Mar 2009
Posts: 22,811
Inverter sizes: For just the Televisions and electronics, including your laptop, a few hundred (like 500 max) will do, My inverters info display says I draw around 250 watts most of the time so a 300-400 watt inverter would do the job.

The Microwave can kick it up by about 1100 watts per it's ID plate,, and in my case the inverter also powers the GFCI outlets.. It is very rare for me to overload it, but then it is very rare for me to actually use it less the Park breaker trips

My inverter is a Xantrex Prosine 2.0 , 2000 watts true sine

3,000 would be needed (minimum) if I wanted to do something like run an A/C.. and I very very very strongly recommend this unless you have room for lots and lots of batteries.

How much battery: A good rule (Well two of them 200 amp hours per kilowatt or 1 pair of GC-2 per Kilowatt (220-230 amp hours) I have a bit more than that.

When I am on a 30 amp site, Since, rather than pay for propane I usually cook with the parks electricity, it is not uncommon to trip the park breaker, epically if I forget to turn the A/C off.. The Inverter takes over nicely the TV's do not even blink, Save for last week when some Idiot (For the record I'm a solo RVER) flipped the switch that disabled the inverter portion of the thing. (Worked much better when I turned it back on).
__________________
Home is where I park it!
wa8yxm is offline   Reply With Quote
Old 05-30-2014, 05:06 PM   #11
Senior Member
 
vsheetz's Avatar


 
Fleetwood Owners Club
Ford Super Duty Owner
Join Date: Jun 2012
Location: SoCal
Posts: 11,793
Attached is my solar system description which includes my multiple inverter setup and component block diagram. YMMV.
Attached Files
File Type: pdf VSheetz - Solar Setup for my RV v1.1.pdf (473.7 KB, 36 views)
__________________
Vince and Susan
2011 Tiffin Phaeton 40QTH (Cummins ISC/Freightliner)
Flat towing a modified 2005 Jeep (Rubicon Wrangler)
Previously a 2002 Fleetwood Pace Arrow 37A and a 1995 Safari Trek 2830.
vsheetz is offline   Reply With Quote
Old 05-30-2014, 05:17 PM   #12
Senior Member
 
ardbark's Avatar
 
Monaco Owners Club
Join Date: Oct 2011
Location: Logan, Ut
Posts: 315
Quote:
Originally Posted by PyrateSilly View Post
Like I said our coach was built with pretty much everything going thru the inverter...
This is the way ours was built, yours does not sound like it was built like that thou.
Sounds exactly like what I would have done - get a big giant sine wave and forget it.

AFAIK mine wasn't built with an inverter at all. It may be wired for one, I have no idea, but there isn't a unit on board. I have a CONverter of course (110-12v) but that's it. The 'ol 96 Endeavor is the last of the simple RV's. Very little electronic wizardry at all. Sure, there's PCBs on appliances to control their functions, but nothing close to the whistles and bells on modern coaches. Heck, I don't even have a computer managing the engine. Well... except for me :-)
__________________
Its not the destination, its the journey
2003 FW Disco 39L chased by 2300 lbs of raging GEO Tracker
ardbark is offline   Reply With Quote
Old 05-31-2014, 07:48 AM   #13
Senior Member
 
Ramets's Avatar
 
Join Date: Jul 2010
Location: Conway, SC
Posts: 2,364
Because I knew I would eventually be adding things to the coach I went ahead and put in a Magnum 3000w PSW inverter. This way I can add just about anything I want, whenever I want. I should mention I have 480w of solar, and AGM's.
__________________
2000 Dutch Star Pusher
2009 Saturn Vue Towed
Full timed for 6yrs.
Ramets is offline   Reply With Quote
Old 05-31-2014, 10:07 AM   #14
Senior Member
 
OLYLEN's Avatar
 
Monaco Owners Club
Join Date: Jan 2008
Location: Olympia, Wa
Posts: 2,337
Most MH's of your size run a 2000 watt to run about anything in the RV. That is what I have and it does what I need to run, all items you have mentioned. But I do have a couple of small one's to charge cells and the like. Normal battery configuration for your size MH is four 6 volt batteries, but or little to no boondocking two may very well be enough. Many small unit's might very well be good for long time boondockers to aid in smaller battery use but does not come cheap and has a need to run several 12 volt supplies. Adding two more batteries might be cheaper and EZer. JMO

LEN
__________________

__________________
2004 Clss C 31' Winnebgo
OLYLEN is online now   Reply With Quote
Reply

Tags
inverter



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
Inverter for whole coach question jdwky RV Systems & Appliances 51 02-25-2016 11:25 AM
Magnum Inverter Question. gemini5362 5th Wheel Discussion 28 05-19-2014 11:28 PM
Dimensions 2000 Watt inverter, no battery charging, need help ASAP! FIRE UP Winnebago Industries Owner's Forum 29 02-24-2014 12:36 AM
Dimensions 2000Watt Inverter LJowdy Winnebago Industries Owner's Forum 8 02-10-2014 06:23 AM
Full Time TV on Inverter max49 Technology: Internet, TV, Satellite, Cell Phones, etc. 18 12-23-2013 09:37 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:43 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.