Reply
 
Thread Tools Display Modes
 
Old 02-21-2019, 05:31 PM   #1
Junior Member
 
Join Date: Feb 2019
Posts: 3
Inverter Questions

I'm starting to spec out the electrical in my camper van build out and am in a quandary. The more I investigate, the more I get confused. I'm a neophyte with RV electrical systems but am trying to determine the best way to go with purchasing my inverters. I'll be needing two (I can explain if needed) - so I have two questions:
1. in order to provide AC power off my 12v house batteries and have the ability to have shore charging capability, is it better to have an inverter/charger as a single unit or to have separate inverter and charger units? The latter obviously makes for a little more complication, but I'm wondering if having singular units gets the best of both worlds?
2. reading many reviews, it is very confusing what inverters are the best, most dependable and long lasting. I've read about many brands: Aims, Renogy, Xantrex, TrippLite, Magnum, to name a few, and get varying recommendations and criticisms for each. Is there a particular brand that stands out that is dependable and won't break the bank?

As for our needs and design - we're building out a 2018 Ford Transit, using the CCP's to power a smaller inverter (possibly 1000watts) which will then send AC power to either an inverter/charger or singular charger, that will charge the house battery as well as provide the input for shore charging. The 2nd inverter (or inverter/charger) will be used for providing our house AC power off the house battery. This probably sounds confusing and begs the question as to why the need for 2 inverters, which I can explain in a rather lengthy response. In regards to the batteries we'll be using, we're leaning towards lithium, knowing the greater cost but many beneficial benefits versus AGM. We'll be using the camper van for both short camper trips as well as lengthy road trips - each of which will include periods of off grid stays. Finally, at some time we'll add solar charging capability as well.

Any help with this is greatly appreciated.
__________________

pfmathis is offline   Reply With Quote
Old 02-21-2019, 06:02 PM   #2
Senior Member
 
1der's Avatar
 
Join Date: Apr 2013
Location: San Francisco, CA
Posts: 1,941
Please explain the need for two inverters.
What temperatures are you going to be exposing your batteries to?
Looks like you are setting up a fully isolated house system? Why?
What are the loads going to be? Induction stove, microwave, electric heater?
Solar plans?

An inverter/charger/transfer switch will make life much easier installing and using.

CCP's - what is this?
__________________

__________________
Ray
Beastie 3: 2002 7.3 EB Cargo: Agile TTB, CCV Mid Top, Custom Walk Through, Lots of stuff added. BlingMyRig.com
1der is offline   Reply With Quote
Old 02-21-2019, 06:43 PM   #3
Member
 
Join Date: Oct 2018
Location: Longwood Fl
Posts: 42
Check out a company Donrowe.com Good prices and tech advise. Make sure you invest in a pure sine wave. I run a Kisae 2000W.,it s been a great unit with no issues over 5+ years. Cable size and length is important also.
Flipperfla is offline   Reply With Quote
Old 02-21-2019, 08:26 PM   #4
Senior Member
 
Scalf77's Avatar
 
Join Date: May 2007
Location: Beaverton, OR
Posts: 1,490
No need to go to an Inverter to power your shore charger, It can and has been done though. I would look at the KISAE DMT-1250 It is a DC to DC battery charger and a Solar Charger, it can support a 50A charge, and does have support for Lithium if you really want to go down that road.


It should hook up to the Transit CCP nicely, and you will have solar ready down the road, it is a cost efficient solution. There are also other brands of DC to DC chargers

-greg
__________________
2004 E350 EB V10 E/PH 2WD
Scalf77 is offline   Reply With Quote
Old 02-21-2019, 10:31 PM   #5
Senior Member
 
86Scotty's Avatar
 
Join Date: Jul 2011
Location: TN
Posts: 8,267
Quote:
Originally Posted by 1der View Post
Please explain the need for two inverters.
What temperatures are you going to be exposing your batteries to?
Looks like you are setting up a fully isolated house system? Why?
What are the loads going to be? Induction stove, microwave, electric heater?
Solar plans?

An inverter/charger/transfer switch will make life much easier installing and using.

CCP's - what is this?
Dave Orton, that's why. Many are adopting his dual inverter ideas. It works but it's convoluted IMO.

Basically, the idea for dual inverters, if I remember right, is to run one inverter off the main battery all the time the van is running to charge the battery bank (instead of just letting the alternator do it). Then you have your house inverter for loads off the house battery. I love Dave but this idea is just totally unnecessary in my mind. OP, is this what you are planning?

@PFMathis, it is a daunting task figuring out and doing this for the first time, no doubt. You will always get great advice here (from Scalf especially on anything electrical). I'd recommend paying close attention. I believe one inverter/charger is all you need. You can basically build a very capable electrical system (AC and DC) with this:

Chassis/van battery with isolator to house batteries - The isolator allows your alternator to charge the house batteries while you are driving via the van's alternator.

Inverter/charger - will be connected to your house batteries turning DC power to AC power. All AC receptacles are run OUT of the inverter/charger.

There is ONE AC line running IN to the inverter/charger. That is your shore power hookup coming in to the vehicle. It allows AC power from home/RV park to provide AC power to the van (without inverting it from your batteries) while charging your house batteries at the same time. If your isolator between the van and house batteries is 2-way it will even keep your van battery topped up when you are plugged in as well.

The only other thing to consider is solar, which is a 3rd way to charge your house batteries. It basically consists of a panel and controller wired to your house batteries. The inverter Scalf recommends above includes the solar controller, so one less thing to buy. This is a good thing.

I hope this helps, if not, perhaps others can explain it better.

__________________
Currently vanless. Weird.
86Scotty is offline   Reply With Quote
Old 02-22-2019, 05:37 AM   #6
Member
 
Join Date: Dec 2015
Posts: 74
Charging the house battery through an inverter and then to a charger is very inefficient. If you are using a 12V house battery, you can have a simple battery isolator that connects the house battery to the alternator when the engine is running. If you have a different voltage for the house battery (or a different chemistry, e.g., LiMnFePO4), you can get a DC-DC converter that will handle the connection, and do so much more efficiently.
As for the main inverter: I would strongly suggest an inverter/charger over separate inverter and charger. An inverter/charger usually will be able to supply MUCH more charging current to the batteries, and do so in less space. More sophisticated units (like the Magnum MSH-4024 I have) will do what is called "load support" - you can program them to limit how much current they pull from shore power, and if your demand exceeds that, they can make up the difference from battery. This is very useful in a couple of cases:
1) You are visiting a friend who does not happen to have a 30A RV receptacle on their house, but they can give you a standard 15A cord. You can program the system to draw not more than 15A, and yet still run 30A of loads (for short periods of time). You draw down the batteries when you do so, but when you are not otherwise using the current, it will be used to charge the batteries.
2) You are at a park with crappy infrastructure, and that "30 A" pole you are on can really only provide 15A before the voltage drops. You discover that in the morning as you try to make coffee and breakfast - you just set the unit to draw what it can from the pole and carry on.
Also, smarter inverters can automatically switch from shore to battery when shore voltage goes too low, protecting your equipment from the brown-out. This means you have less need to have an autoformer to regulate shore power, so that's another Big Heavy Thing you can leave out of your limited space.
(all the above scenarios are taking from actual experience).
Wowbagger is offline   Reply With Quote
Old 02-22-2019, 06:13 AM   #7
Senior Member
 
Scalf77's Avatar
 
Join Date: May 2007
Location: Beaverton, OR
Posts: 1,490
I am aligned with Eric (86Scotty), my thought is his intent for two inverters was to use so he could charge his house battery while driving. It has also been mentioned in this forum http://www.sportsmobileforum.com/for...tml#post234319 by member Mike Wilson. see his diagram post *149. I believe his description starts at #143. The basic scenario is that you use an inverter off of your alternator/start battery to provide AC to your shore charger. This of course charges your house battery while you drive. In Mikes application it turns his alternator into a 3 stage battery charger.

I would agree that it had multiple levels on inefficiency, We are converting to DC to AC and then AC to DC, you always loose some power in those conversions.


The fact that OP want's to go to Lithium batteries mean that the typical isolator/separator solution won't really work. In that case the best solution is a dedicated second alternator with Balmar regulator on it that supports Lithium, or a DC to DC charger from Sterling Power , or the KISAE DMT-1250 I referenced in my previous post.

On second reason to have two inverters, would if you wanted a large inverter to handle your heavy loads say 2000 to 3000 watts, but wanted a small 400 watt unit to handle small conversions, that become more inefficient with the larger unit.

Those are the two reasons for two inverter off the top of my head.

-greg
__________________
2004 E350 EB V10 E/PH 2WD
Scalf77 is offline   Reply With Quote
Old 02-22-2019, 06:29 AM   #8
Senior Member
 
BrianW's Avatar
 
Join Date: Apr 2012
Location: Philadelphia, PA
Posts: 3,085
I use two inverters in my van, but as Scalf suggests: a very small one for one-off things like my laptop charger, and then the large 1500 watt one that runs all the AC outlets in our all-electric van (no propane). A lot more efficient than turning on the bigger inverter for a small load.
BrianW is offline   Reply With Quote
Old 02-22-2019, 09:18 AM   #9
Senior Member
 
1der's Avatar
 
Join Date: Apr 2013
Location: San Francisco, CA
Posts: 1,941
Okay, a little better understanding.

I know Dave Orton personally, great guy, very accomplished engineer, and super passionate about vans. He is very creative and thinks out of the box for his builds which is great. I admire Dave a lot. We have spent many hours discussing our respective builds.

Dave’s primary use of his rig is short term, stealth type camping and his build is skewed to urban overnights/ multi nights for one person. He has optimized his set up for this. He has clear desires for certain comforts and conveniences and less desire for other functionality he does not find necessary. I respect his commitment to building what he wants / needs.

In building out our van, multi week ski trips staying in the van nearly every night was high on the list of needs. This dictated a heater. This dictated insulation, this dictated layout for gear, lounging, sleeping for two adults, possibly three adults. Plus we like to have visitors in for dinner and visits. Dave has no needs for these things in his builds.

So, back to inverters and systems - I strongly considered the two inverter idea. I even bought two inverters. I used the second smaller inverter maybe twice before deciding it was more of a pain. Really, what was I saving in amps? We have 360 watts of solar, our house and engine batteries are AGMS, combined to provide 480Ah of capacity. The solar has the batteries in float from typical overnight three season usage by noon /1pm. Winter - if it is clear has been no problem. If snow is covering the panels, we are good for three days without starting the engine. Winter time and downhill skiing pushes us into RV parks since most campgrounds and sideroads are closed. So we have shore power available.

The reason I asked about temperatures has to do with battery type selection. I am not yet convinced Lithium is the way to go for a four season camping rig. The issues with charging/maintaining Li below 32 degs F are too complicated for me to see risking thousands of $$ and risk of failure in a remote area. Some people I know who are a journey to Patagonia had their Li batteries fail in Guatemala, there was no way to replace them there, so they converted to AGM. Cutting edge can have it’s painful moments. Ability to service and repair on the trail / on the road is important to me. A second complete charging system, elimination of redundancy, introduction of incompatibility? Why?

Remote travel brings with it the risk of breakdown and possibly a survival situation. If my rig is my “lifeboat”, I want it to be a Swiss Army knife.

Last up for this post is convenience- I have found if a system/feature/component is complicated, requires additional effort to setup/ manage/ deploy/stow, it gets used less and less. Our solar is virtually automatic and ties into our Samlex EVO 2212 inverter/charger/transfer. Shore power - plug in, flip the main in the van on and the EVO unit transfer switch charger takes over automatically. Solar (lots of it) has been the biggest lifestyle changer - it is luxurious.

YMMV - and what works for us may not work others. Design your van around your use profile and ability to self repair.
__________________
Ray
Beastie 3: 2002 7.3 EB Cargo: Agile TTB, CCV Mid Top, Custom Walk Through, Lots of stuff added. BlingMyRig.com
1der is offline   Reply With Quote
Old 02-22-2019, 10:43 AM   #10
Junior Member
 
Join Date: Feb 2019
Posts: 3
Everyone - thanks for all the input. I'm going wade through all this and probably get back with more questions. As mentioned, planning the electrical system for your van is a daunting task. Thanks.
__________________

pfmathis is offline   Reply With Quote
Reply

Thread Tools
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

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 08:09 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.