Solar Powered RV

I was thinking of building a semi-portable install for enough solar panels to power my rig's A/C:

First, the inverter. Easy peesy -- I'd go 3000/6000 watts to handle the A/C's locked rotor amps, or 2000/4000.

Now the pain begins: I'd need enough batteries to last 24 hours, guesstimating eight hours of sunlight a day. That means I need 36kwh, or 3000 ampere-hours. Since batteries get damaged if discharged past 50%, double that.

6000 Ah means I need 30 or so 12 volt batteries. At ~50 pounds, that is 1500 pounds of weight, and that's not including the very thick gauge cables needed in parallel, as well as the connectors and a very good crimp tool. I'd probably need to go with a good bus bar on both sides. I'd need some heavy duty fuses because one short and I will have a sizable fireball on hand.

Now the panels: Factoring three times incoming charge as outgoing, I'd need 4500 watts in panels. Which means 15 300 watt panels, preferably 12 volt so I can run them in series with a MPPT controller. I'd need multiple charge controllers, so I'd need four MPPT controllers (assuming 48 volts is the max they will swallow, so all but one controller will get four panels.)

Of course, this is doable... but very expensive.

Cheaper to just buy a top tier generator, stick in a ventilated, soundproof enclosure, and call it done.

barbalace wrote:
Is there a way to run the Motorhome with solar panels (especially the A/C and microwave)?
If so, how much do I need?

No.

http://www.roadtrek.com/faq.aspx

How long will the coach air conditioner run off of the batteries? Will it run all night while I am sleeping?

It depends on how hot the outside temperature is, how much charge the batteries have when you go to bed, and how cool you set the temperature in the coach.


How long has the air conditioner ran off the batteries in testing?

In testing, we have run the air conditioner for 9 to 15 hours, when the outside temperature was 95 degrees F and there were no other items on in the coach. The batteries were at full charge to start these tests. The various tests have had doors open, doors closed, and really pushed the limits of the coach.

Francesca Knowles wrote:
.Does the O.P. have a Roadtrek?

I doubt it. I think the poster was simply bringing up a point about *any* RV running air on batteries- for comaparison.

BTW, this is OP's first post, and I see in his profile he has a website. I did not click it.

:h

I seem to have missed something...Does the O.P. have a Roadtrek?

I only saw "motorhome" and took that to mean something bigger than a "B".

MNtundraRet wrote:

bob_nestor wrote:
The Class B Roadtrek E-Trek is all electric. According to some of the early press releases they claimed you could run the A/C for a full 8 hours on the batteries and recharge them in about 20 minutes with the engine alternator. I'd image they were thinking the user would have opted for the $20K Lithium-Ion batteries, but I still find it hard to believe. But then again, it was posted on the Internet so it had to be true. After all, "they" don't allow anything on the Internet that isn't true. I think Abraham Lincoln said that.

Where is the link:h

Don't claim B.S. unless you can prove it. I remember reading past information on this unit without this claim.

Whoa! I seem to have struck a nerve here not providing links or background. OK, someone else provided the link. My background is being an engineer educated in Missouri (the Show Me state), and I happen to own a Roadtrek 210. The two batteries in it on full charge can barely provide enough power for one pot of coffee. The refrigerator running on DC is a power sucker. My previous RV was a 21' Chinook with solar. The solar couldn't keep the batteries charged on a hot Texas summer day and the refrigerator alone could suck the batteries down in just a few hours. And in my day job I support systems that use large Lithium-Ion battery arrays. Call me skeptical about the E-Trek, but until I've seen it operate as they've tested it in the real world I'm not a believer.

The E-Trek has a relatively small interior volume as compared to a Class C, so I imagine that it's air conditioner is a bit smaller than the typical 13,500 BTU Class C air conditioner - hence less battery amp hours to run it.

Probably the air conditioner run times they talk about are with their largest AGM battery bank option - eight AGM batteries for a total of 1600 amp hours. Their optional lithium ion battery package is two batteries for a total of "only" 800 amp hours. They state that the reasons to select their LI battery option would be to reduce overall RV weight and to get the shortest coach battery bank recharging time.

As a side note, the Earthroamer RV also powers it's air conditioner from it's AGM coach battery bank - as it doesn't have any 120V AC generation capability on board (just two large alternators driven by it's diesel main engine).

Look around on this E-Trek page to eventually get to what they claim.
Click on their photos and also look for their E-Trek questions and answers section:

http://www.roadtrek.com/etrek.aspx

bob_nestor wrote:
The Class B Roadtrek E-Trek is all electric. According to some of the early press releases they claimed you could run the A/C for a full 8 hours on the batteries and recharge them in about 20 minutes with the engine alternator. I'd image they were thinking the user would have opted for the $20K Lithium-Ion batteries, but I still find it hard to believe. But then again, it was posted on the Internet so it had to be true. After all, "they" don't allow anything on the Internet that isn't true. I think Abraham Lincoln said that.

Where is the link:h

Don't claim B.S. unless you can prove it. I remember reading past information on this unit without this claim.

The Class B Roadtrek E-Trek is all electric. According to some of the early press releases they claimed you could run the A/C for a full 8 hours on the batteries and recharge them in about 20 minutes with the engine alternator. I'd image they were thinking the user would have opted for the $20K Lithium-Ion batteries, but I still find it hard to believe. But then again, it was posted on the Internet so it had to be true. After all, "they" don't allow anything on the Internet that isn't true. I think Abraham Lincoln said that.

barbalace wrote:
Is there a way to run the Motorhome with solar panels (especially the A/C and microwave)?
If so, how much do I need?

Sure! This'll do, for starters. ;)