24hr A/C runtime on batteries - how to do it?

[booster]

Originally Posted by Davydd

How can they get 1500 watts of solar on a Class B? Can anyone speculate? Here is what I believe is 500 watts of solar on an extended body Sprinter - Advanced RV's Mzungu.

My guess would be that they would have to have them stacked when traveling, and deployed when parked. 500 on the roof, 500 each way like an awning maybe that slide out?

[gerrym51]

I don't think the 1500 watts of solar was a serious thing. Jim was clowning with Campskunk on that one.

[Davydd]

So was 24/7 air conditioning serious? I'm still trying to get my mind wrapped around why anyone would want to pay for that, or worse, give up space for it if the case in a space precious Class B.

Booster, That would be an interesting array. It is pretty common to see portable solar deployed in campgrounds but I don't recall much more than maybe 100 watts that way. Awnings would be an interesting double-duty idea. Have you, from your experience now, attempted to do the numbers on what it might take to run air conditioning 24/7?

I'm also trying to figure out where 24/7 would be needed. Not in the desert generally except maybe in the summer. Not in the mountains. Not even in south Texas except maybe in the summer. Definitely not if you go to Alaska. Odds you'll never run your air conditioning as we didn't on our trip. It would definitely be overkill for anyone in the upper Midwest. For those in the south (AZ, TX, FL, etc.) that whine about their summer heat and humidity. I would say get a clue if you want to tour in a Class B and head north or high altitude, get outdoors, and enjoy the way a B was intended.

[gerrym51]

Originally Posted by Davydd

So was 24/7 air conditioning serious? I'm still trying to get my mind wrapped around why anyone would want to pay for that, or worse, give up space for it if the case in a space precious Class B.

Booster, That would be an interesting array. It is pretty common to see portable solar deployed in campgrounds but I don't recall much more than maybe 100 watts that way. Awnings would be an interesting double-duty idea. Have you, from your experience now, attempted to do the numbers on what it might take to run air conditioning 24/7?

I'm also trying to figure out where 24/7 would be needed. Not in the desert generally except maybe in the summer. Not in the mountains. Not even in south Texas except maybe in the summer. Definitely not if you go to Alaska. Odds you'll never run your air conditioning as we didn't on our trip. It would definitely be overkill for anyone in the upper Midwest. For those in the south (AZ, TX, FL, etc.) that whine about their summer heat and humidity. I would say get a clue if you want to tour in a Class B and head north or high altitude, get outdoors, and enjoy the way a B was intended.

david-the 24 hours of AC was serious. however the post that contained the 1500 watts of solar was during a humorous exchange between campskunk and Jim Hammill- they were musing weel we could do this or we could do that-Jim Hammill will not reveal what he plans on doing. we can guess though-the same basisc e-trek sytem using big lithium batteries could do it.

[Davydd]

If the 1500 watts of solar was not serious, I am wondering if a fuel cell solution is in the works and the solar business was a diversion.

[gerrym51]

Originally Posted by Davydd

If the 1500 watts of solar was not serious, I am wondering if a fuel cell solution is in the works and the solar business was a diversion.

fuel cells are interesting but the ones available don't seem to generate enough power based on size and price.didn't roadtrek have a fuel cell when e-trek first came out and nobody bought it. i cannot remember the name?

[booster]

Originally Posted by Davydd

Booster, That would be an interesting array. It is pretty common to see portable solar deployed in campgrounds but I don't recall much more than maybe 100 watts that way. Awnings would be an interesting double-duty idea. Have you, from your experience now, attempted to do the numbers on what it might take to run air conditioning 24/7?

If you expand on Marko's calculation here:

http://classbforum.com/phpBB2/viewto...&t=3186#p21216

And figure about 30AH per day per 100 watt panel (optimistic), you would need about 6000 watts of solar to break even at his 50% run time scenario.

[booster]

I think I have all this figured out!

They are going to use a swamp cooler, and the sealed magic box is just full of water.

[markopolo]

Nope I think Jim already said no evap cooler in the old topic. They are interesting but lose effectiveness as % relative humidity increases. Charts: http://www.turbokool.com/cooler.html

My guess: 3000 ah Lithium Iron Phosphate batteries. I think they'll make sure to meet or exceed that 24hr target.

[gerrym51]

he said no generator-but i think he was taliking about onan. the underhood generator(which is actually high output alternator) was not mentioned one way or another.

[Arlo]

The fuel cell offered in the E-Trek is by EFOY.

[gerrym51]

Originally Posted by Arlo

The fuel cell offered in the E-Trek is by EFOY.

thanks-that was it -no longer offered

[Davydd]

Maybe a revisit with fuel cells considering they must have already invested some research time with them? Time does solve problems.

The second alternator is a standard with Advanced RV with an auto start feature but my understanding is per Mercedes Benz you would get a maximum of 3 hours at high idle before you would have to drive off for about 40-45 minutes on the road. Advanced RV is governing at 2 hours. 22 hours to go. I know that is a simplification but you do have to balance charging with your batteries right? Exactly what does it take to charge batteries enough to keep air conditioning running 24/7? If you say 24/7 doesn't that mean sitting somewhere and going nowhere for 24/7? So, why I ask if fuel cells are being revisited? If no generator you have to have an input energy source.

[Davydd]

Maybe it is this...

I've been getting bombarded with emails and Facebook news about Nikola Tesla's free electricity secret.

http://www.teslaenergysolution.com/?hops=jer143

Warning. I have not watched to video.

[booster]

Originally Posted by Davydd

Maybe it is this...

I've been getting bombarded with emails and Facebook news about Nikola Tesla's free electricity secret.

http://www.teslaenergysolution.com/?hops=jer143

Warning. I have not watched to video.

That looks like the kind of web site you just wouldn't want to click on anything on it!

[markopolo]

I haven't done any calculations for the recharge time. That's where this gets more complicated.

Also, it's 24/1 not 24/7 At least that's my understanding - run the A/C for 24hrs. Then (I assume) recharge.

If the recharge is anything like the 1800 amp hrs I guessed at here: http://classbforum.com/phpBB2/viewto...&t=3186#p21215 then that is a lot. That's the real challenge.

So many, too many unknowns.

The folks at RT have a few years experience with the E-Trek now so Jim must be pretty confident that they have the tech to do it.

[bikerbill]

Actually Davydd I spoke with Mercedes Customer Service last month and asked "How long can I idle my 2013 Sprinter 3500? 45 minutes any problem?" Their answer was "You can idle your engine for an hour easily but then you should drive it for say 30 minutes or so and then you can idle it again for another hour without any detrimental effects to the exhaust system."

I posted that on the Roadtrek Facebook page after many comments from many who are and were uninformed and opinionated about lengthy diesel idling and its affect on the engine and warranty. Kinda put that problem to bed, for a while. But then there are always naysayers who don't believe what is posted on the Internet. So I say, call Mercedes yourselves if in doubt.

[booster]

Originally Posted by bikerbill

Actually Davydd I spoke with Mercedes Customer Service last month and asked "How long can I idle my 2013 Sprinter 3500? 45 minutes any problem?" Their answer was "You can idle your engine for an hour easily but then you should drive it for say 30 minutes or so and then you can idle it again for another hour without any detrimental effects to the exhaust system."

I posted that on the Roadtrek Facebook page after many comments from many who are and were uninformed and opinionated about lengthy diesel idling and its affect on the engine and warranty. Kinda put that problem to bed, for a while. But then there are always naysayers who don't believe what is posted on the Internet. So I say, call Mercedes yourselves if in doubt.

That hour of idling is actually less than some others have heard from MB, before a drive, so it is on the conservative side. What are the naysayers saying, no idling? That would be beyond anything I have heard, which were just different variations of how long you could idle before a drive, and then how long a drive. I think it all got started with Roadtrek's etrek claims of running the air conditioner for extended periods off the engine generator, which could lead to 8+ hour of idling, way beyond what you are talking about. There was a MB tech bulletin posted that had some actual numbers on it also, but I don't remember where it was.

[gerrym51]

I think the naysayers are getting a bad rap. NOBODY ever said you can't idle sprinter van. the question has always been -EXCESSIVE- idling which can foul up a DPF faster. The question is that nobody has ever been able to define 'excessive idling'. one persons excess is anothers short period of time.

[booster]

Originally Posted by gerrym51

I think the naysayers are getting a bad rap. NOBODY ever said you can't idle sprinter van. the question has always been -EXCESSIVE- idling which can foul up a DPF faster. The question is that nobody has ever been able to define 'excessive idling'. one persons excess is anothers short period of time.

Yep, that is why I was asking what they were taking issue with, as his one hour is really on low side of what we have heard, if you disregard the very early 20 minute thing that went on when all this first surfaced. Most everyone I have seen would not call the one hour excessive, so it is hard to understand their outrage. I actually am somewhat of a naysayer, but more to the side of not wanting any of that kind of limitation, especially if it gives MB an out on warranty claims, which is still undetermined. If folks are saying the MB is a bad vehicle because of the idling issues, I think they really need to be saying the MB could be a bad vehicle for folks that can't/don't want to stay within the requirements, not a blanket statement about the overall vehicle.

On edit- just reread bikerbill's post. Are the naysayers saying you should be able idle longer, or not that long. Good chance I got it the wrong way (at 50-50, I will be wrong 80-20 based on past experiennce)