Under the hood generators, dual alternators etc.......

[booster]

Originally Posted by gregmchugh

Agree but Roadtrek has fostered the idea that a 1/2 hour underhood generator run will recharge the batteries without providing any type of details. Many people hear the statement and reasonably assume it means bringing a fully discharged battery up to full charge.

Very similar to the 45 minute recharge claim made for the etrek in the beginning.

[gregmchugh]

Anybody who has a technical background will be frustrated by the Roadtrek strategy of treating all customers as if they were their average customers who just want to buy a van and use it without having to know anything about how it actually operates. I got slammed by Jim one time when I suggested that they should use actual valid engineering units in their brochures and specs instead of the phony units they are now using. He said that real units are too hard to understand for their customers. So, we now get battery capacity in watts and a Zion 12v AGM 400 battery that has 185 amp hours of actual capacity and owners manuals with no technical info or system diagrams. They have done a good job of creating an aura of super secret high technology that must be protected from competitors and their typical customers have bought into this comparing the electrical system to actual advanced technology such as a Tesla. Their main rival in terms of the technology who has basically the same thing on the market reveals all the details of the technology for everyone to see and understand showing that they field the same technology using off the shelf third party readily available systems with some added software development for system wide control. I will give Roadtrek credit for leading the way for the larger market and they should be rewarded for taking the risk of going first and capitalize on their current leadership position.

[Davydd]

Originally Posted by gregmchugh

Agree but Roadtrek has fostered the idea that a 1/2 hour underhood generator run will recharge the batteries without providing any type of details. Many people hear the statement and reasonably assume it means bringing a fully discharged battery up to full charge.

Keep this in perspective, pprevill said a Roadtrek Salesman, not Roadtrek in any official way. Have you met many RV salesmen who have actually used RVs in real life especially the current products? Or maybe he had and was talking about not a fully discharged battery but a battery after an overnight stop partially discharged.

I have fully charged my li-ion batteries after an overnight late stop, at say a Walmart, in as little as 20 minutes. Most typically an early afternoon stop and campground stay with a very liberal use of power will discharge batteries as much as 200ah with induction/microwave cooking, brewing coffee, 12v refrigerator, etc. and leaving the inverter on 24/7 to have fully transparent use of all electrical systems. They will recharge in under an hour of driving on the highway. That's recorded observable average experience and not theoretical and optimum calculations covering 209 nights now.

A second alternator charges faster than a chassis alternator, shore power or an Onan generator.

Roadtrek Volt Start or Advanced RV Autogen will start your engine and recharge batteries. That is a keyless unattended automatic restart. We rarely have invoked that feature other than testing or letting it go down at home to see how it works. We have started it a few times deliberately on the road camping because even with li-ion batteries we have rarely let them go below 50% SOC. It is kind of a more safe than sorry attitude on multiple days in one campground and I really don't want it to auto start unattended if I can prevent it.

With a high ah battery bank and a dual alternator and driving frequently, solar becomes inconsequential, IMO. For one if you drive during the day when the sun is up solar is not needed. Late in the day and overnight solar is not contributing. Camping in the winter months with an extremely low sun angle rooftop solar does not perform anywhere near what is estimated. Camping on cloudy days, rain, or in the deep woods, solar can't be relied on. If you have small battery bank of 200ah or less and no dual alternator I can see a solar contribution, but then you would be conserving power as much as possible and solar can replace that amount.

I like living on the road indefinitely off-grid free of shore power and transparently with full use of all our electrical systems as you would use if plugged into shore power. That could include air conditioning but we plan our trips accordingly to avoid air conditioning and we can keep our B the same as the outside air temperature for the most part with our screening. In a campground it is our intent to live outside as much as possible. If not, why go where you will feel miserable or camp? Or get a big ass huge Class A, plug in and be comfortable just like home.

[markopolo]

Originally Posted by pprevill

Hello all,

I read all the post in this topic, I'm probably more confuse than I was before so I need a little bit of help !

I just buy a new Safari Condo LSX based on a GMC Savana 2016 frame with a V8 4.8L. The mothorhome have two AGM 190A/h batteries. I was concerned about the autonomy of the vehicule since we always want to use it unplugged. The saleman told me that the alternator is 242 amp and i need to drive 3 to 4 hour at highway cruise speed to charge the battery. I also have 3 90W solar pannel on the roof.

I find that 3 hours at hwy speed is very long to charge the batteries. That is why I am so interested in this topic. I have discuss with a roadtrek saleman while I was shopping for the mothorhome and he confirm that any roadtrek with the underhood generator can charged 400amp battery bank in 30 minutes iddle speed. That is interesting ! I mean, a 30 min slow drive to get some milk coud charge our batteries.

So I'm wondering if anyone can help me understanding my current (future) setup on my van (Why it take so long with a 242 amps alternator to charge two AGM batteries) and how I can boost this with a underhood generator ? My other idea was to buy a honda 2000 generator get it modifed to be able to run on propane, plug it to my van propane tank. Underhood generator is more convenient...

Thank you !!

I didn't realize the Chevy's were coming with a higher output alternator now. Check the RPO code sticker on the van for code KW5 - that's for the OEM 220A alternator.

If the wiring is adequate then you might get 100A+ available to the house batteries but the batteries won't utilize all of that 100A+ (or if they do it won't be for long). It's just how AGM's work.

See this post: http://www.classbforum.com/forums/f2...html#post36926 to get an idea of the throughput from an older 124A GM alternator (upgraded wiring).

With 3 x 90W panels it should all work nicely.

How many DC (compressor) fridges in your van?

[gregmchugh]

Davydd, all very true and completely understood.

The issue I was highlighting was the fact that Roadtrek buyers really have very little real information that they can use to decide which of the technology options make sense for how they plan to use their van. Roadtrek could provide some simple guidelines to help with the decision process rather than only making simplistic marketing videos of the features. In terms of sales people at the dealerships, I think that is a lost cause, they will continue to range from the traditional know nothings to the ones who really understand the product and actually help the customer buy what is appropriate.

It does appear to me that many buyers seem to have plenty of disposable assets and end up getting high end options that they are not likely to ever take advantage of. Keeps the factories humming which is good I guess.

[Davydd]

Greg,

The real decision process is do you want to travel as we have traditionally traveled in Bs watching, compromising and conserving your energy use or do you want full transparency plugged in or off-grid little thought about your energy use. There is also a range in between. As far as Roadtrek is concerned, and it comes right from Jim Hammill, is the latter in that you should never have to rely on shore power and Roadtrek is trying to provide the systems to achieve that. He is somewhat vocal about that.

So how do people conclude what they want if they are new to RVing? 99% of the examples of Class Bs are more of the former so asking about the subject is difficult to get real life experience. With salesmen it is much more difficult for them to answer. In my case, I already had two Class Bs and I was more focused from experience what I wanted to achieve. Advanced RV's owner, Mike Neundorfer, did have specific goals for how to travel and use a B based on direct experience and also having previous Class Bs. Fortunately for me those coincided. There was no sales talk in my case. I've always been an early adopter in attitude.

My prediction. Within 5 years most all converters will be offering larger li-ion battery banks, high watt inverter/chargers with dual alternators and it will become the expected norm in Class B travel. There may be other technologies coming online but they will be technologies with the same goal of off-grid electrical transparency.

[gregmchugh]

Davydd,

Yes, I think we are in agreement on all this and I agree on the future direction for smaller RVs is a continuing move away from traditional campgrounds with hookups and towards energy independence. I also agree that people will only understand how they will use an RV by actually doing it for real. Some research might keep you from having to buy too many before you hit the right spot though. After 4 years experience in our 08 RS I think we have a pretty good idea of what makes sense for the next one. Not sure we are young enough to get beyond one more though...

Greg

[booster]

I mostly agree with what davydd says, but would add one caveat. As the market progresses toward bigger lithium packs, big inverters and shore chargers, engine generators, etc, I hope the do not all go the all electric, high consumption route like davydd's ARV is. It may be fine for his use patterns and desires, but for others, including us, having the parasitic and necessary power use at a low enough level that the solar can be a significant factor in recovery, would be much more desirable.

With the larger tank sizes that davydd has, consumption in the 75ah per day or less, 400-500 watts solar, we would be able to off grid, no drive, indefinitely or until the tanks were full. Idling works to get power back, of course, but even that would be much faster if you could recover a days use in less than 30 minutes in an emergency, instead of an hour or more. We would prefer to never run the engine if not necessary, and we like to be in one place for quite a while. 14 days in a single spot is not unusual for us.

[Keyne]

Originally Posted by gregmchugh

Davydd, all very true and completely understood.

The issue I was highlighting was the fact that Roadtrek buyers really have very little real information that they can use to decide which of the technology options make sense for how they plan to use their van. Roadtrek could provide some simple guidelines to help with the decision process rather than only making simplistic marketing videos of the features. In terms of sales people at the dealerships, I think that is a lost cause, they will continue to range from the traditional know nothings to the ones who really understand the product and actually help the customer buy what is appropriate.

It does appear to me that many buyers seem to have plenty of disposable assets and end up getting high end options that they are not likely to ever take advantage of. Keeps the factories humming which is good I guess.

Greg, I totally agree that they should provide better information on how to evaluate the different options. We are looking at RT, PW, etc. and it would be great to have the information nicely displayed to know the impact of different option configurations. I searched online to try and find something that explained it all (e.g. Roadtrek E-trek and other options demystified, or "My Roadtrek Boondocking Build")... but couldn't find it other than reading posts here and on the Sprinter forum.

Especially for the E-Trek it would be great to evaluate that vs. PW or a custom setup. I like knowing the things work but its difficult to find the info. I would think RT might actually sell more highly configured vans vs other builders like PW if they explained in normal terms (with technical backup) what it all means.

For instance... an E-trek configured can mean X number of days off grid using XYZ. Ability to run AC, volt start, etc. Then compare that to a RT CS with certain 200,400,800 modules installed. Obviously some factors may vary due to use but that could be explained as well (e.g. 10% tolerance +-). That information compared to a PW build could direct more people to RT because they see the value in the RT technology that PW may not offer.

[Davydd]

5 days in a single spot is my maximum and that is not without driving somewhere during those days being it out to explore or going to the grocery store or restaurant. If I found myself in "vacation" mode or "snowbird" mode of destination A to B, then I would not want to be in a Class B. I'd rather be in a cabin, condo or much larger RV with a toad.

400ah of lithium ion batteries can keep you off grid indefinitely if you desired. 200ah would be in between watching, conserving and compromising as I previously stated.

Solar in the winter has to be directional. Flat on the roof is a waste. Once you have 400ah, solar becomes insignificant in the winter.

As for high use, I said worry free transparency same whether plugged in or not. Until you experience it you are relying on past experience in attitude. It is one of those I won't go back things. BTW, Roadtrek does recommend turning your inverter off when you don't need it which is most of the time. But when you go to brew coffee or want to plug into you 120VAC outlets and realize you have to turn it back on, and you don't have to turn it off anyway (transparency again) why bother? On ARV it is a Silverleaf touch screen button. On Roadtrek I believe it is open the back door and flip a switch.

[booster]

I think davydd missed my point, this is not about how he uses his van, it is about how others may want to use their's. One major point of reducing the amount of power used per day, without losing functionality, is to make it so the solar can tribute, even in winter, although winter camping in the north would be a problem. If you have decent temps, you will also have enough sun to contribute, almost all the time. Another point of lower use it to make the batteries last longer if there is bad sun, 600ah of usable power will go 8 days at 75ah a day even without solar contributions, and 2 days at 300ah per day. If it is 100ah a day, you still get 6 days. If you do use 300ah a day and go over 2 days, with no solar input, you are looking at near near two hours of idling, I would think, to recover one day's use.

I see the above to be just as much about being carefree and non-monitoring as using lots of power but knowing you drive a lot to cover it.

[gregmchugh]

Roadtrek has a wall mounted inverter on/off switch in a handy location, no need to use the one on the inverter...

And you also get a two button control panel for each 200 amp hour Ecotrek module which gets a little unseemly for a 1600 amp hour configuration...

ARV has the control functions handled very nicely as usual...

Roadtrek is bringing back the Coach Connect option with a touchscreen so maybe things will get less cluttered...

[obgraham]

If I might chime in with my usual "both views are correct" attitude:

I'm not here to defend everything Hammill and RT have done. My big criticism of them is that they design and turn out products which are not ready for the market, and their QC is not up to the task. So then they have to endure the bad publicity of folks trying to get their rig to work as designed -- meanwhile RT is on to the next greatest thing.

However, Hammill's approach has indeed worked for me in the 8-AGM CS ETrek. I struggle to understand all the nuances of the system: how it is designed, where the various voltages come from, and much of the detailed discussion led by Greg and others here.

But in practice my rig has worked exactly like Davydd states. I turn it on, head out, usually drive a bit each day when we are out visiting parks or scenic spots. We don't often need the A/C because we avoid those places. I run all the appliances (Keurig, InstaHot, electric skillet, entertainment, etc) with no regard to electricity conservation, and have never yet either plugged into shore power on the road, nor received a low battery alert signal. So in that regard I am the exact customer Hammill was aiming at.

Perhaps a detailed spreadsheet of power production and consumption would aid others who have different needs, but there are so many variations that it seems a task destined to leave customers frustrated.

Now, perhaps if my AGM's prematurely crap out because I don't follow a rigid plan of charge maintenance, I'll sing a different tune. But for now, yes, it works.

I just wish the factory could get all their s**t together.

[Davydd]

Greg,

I asked the Roadtrek rep at that Phoenix Super B show why they recommended turning the inverter off. Obviously I know my answer -- to save about as much as 4 amps per hour draw or about 96ah in a 24 hour period. If I had a 200ah battery bank I would probably do that. It just doesn't enter into my equation. Anyway, he showed me that it was "simply" a switch right at the inverter in the back under the sofa. He didn't say anything about a handy location. That was pretty much why I made that comment.


Booster,

If I wanted to practice electrical use conservation like you talk about or what I had to do with my two previous Bs I could sit for extended times without driving or idling. I know from testing I could go 6 days like that as I did it in my sister's driveway. Theoretically 8 days at 75ah usage. You may forget in my use, I have eliminated propane entirely. That accounts for some increased electrical use in cooking and the refrigerator. I could shut off things like the internal wifi and I suppose turn off the Silverleaf screen and back Pioneer receiver unit. I have no idea if the upgraded JL Amplifiers and subwoofer are drawing anything parasitically as all sound comes off the house battery. I could turn off the inverter but I have the 120VAC operated articulating beds and it is just plain more convenient to leave the inverter on. Since the beds operate on Bluetooth technology for control I would imagine they have some parasitic draw. Yes, I am enjoying a lot of perks. I don't have to use all that electrical power. I choose to use it. If you don't have it then you have no choice.

I think you overestimate flat on the roof solar power panels. I already said in scale they would have more impact in a less battery, less power use setup. AM Solar says a 100 watt panel can get 6 amps per peak sun hour or about 30 per day (5 hours). So theoretically with 420 watts solar I could get 126 amps per day. In the winter that is highly optimistic. At peak noon in February in the southwest I am guessing when I observed at best 11 amps charging and probably less than 50 per day considering the extremely low sun angle or short days. December and January would be worse. 50ah on the battery can be made up idling the engine with the dual alternator in the time it takes one to brew coffee.

Maybe I can explain it in another way. The technology is available to do as I do. Why compromise? Think of a carpenter trying to make his job easier, faster and more profitable. Why give up power saws, electric drills, and nail guns if available?

Being this is the dual alternator topic I think the decision is a slam dunk over an Onan. Less weight, no taking up space other than space never used under a hood, much faster charging, less maintenance, no second combustion engine to deal with, no "exercising", more inadvertently usable (i.e. trip to store charges), quieter, more stealthy operation, more reliable and less costly per Roadtrek's numbers.

[Keyne]

As it relates to a 2nd alternator vs a regular generator... are there off the shelf (e.g. DIY) parts or kits to setup an auto-engine start system like Voltstart and the ARV, or are those proprietary engineered arrangements not available on the open market yet?

I would think with remote start options being available from MB on Sprinter vans it would be possible to have a controlled setup to start the engine and run the alternators.

[booster]

Again davydd misses the point. Different systems could use less power without sacrificing or conserving for how others use their units, like us. Never said that yours isn't fine for you.

You consider having propane a detriment, we don't see it that way, and would not be without for outside cooking off the van big tank. You don't consider having to drive or idle every couple of days a compromise, but we do. To each their own, not everyone wants/needs the same stuff.

Lots of people like to backpack all their stuff where they are going and sleep on the ground, should they also be buying an RV because you have one, and wouldn't do the backpacking? Others think anything under 40' is too small and inconvenient, so a B would be a huge compromise to them.

Insisting that other people's opinion and desires are wrong because they don't agree with you, is just plain silly.

So now back to underhood generators and alternators, which can be used with lots of different configurations of electrical systems and use patterns depending on personal choice.

[pprevill]

Originally Posted by markopolo

How many DC (compressor) fridges in your van?

1 nova kool 3.5 cu. ft. 2.2 vdc

[booster]

Originally Posted by pprevill

1 nova kool 3.5 cu. ft. 2.2 vdc

That frig will probably be using 25-50ah per day depending on weather and use.

Did we ever find out if the amp hour total was 195ah with two six volt batteries or 390ah with two big 12v batteries?

[pprevill]

Originally Posted by booster

If you are trying to live without ever using shore power, probably the best you can do is drive until the batteries are 85% full early in the morning, and then park in the sun and let the solar take them as far as it can after that. Several of us on here do that, and it works OK, but will rarely get you totally full unless you start out nearly full and have very good sun conditions. Not ever getting full will reduce the battery life a lot.

The Roadtrek guy was talking about the lithium batteries they have available that will charge fast all the way up to nearly full, and never have to be charged all the way full like AGMs do which changes everything and makes life on the road a lot easier.

Thank you, great advice, the Safari Condo van are simple and don't use a lot a electric widget but AGM batteries seem to have a lot of downside, I will definitivelly get a trimetric on ma van ! With that said, not sure with my setup a second alternator will get me totally off grid, probably Lithium Ion battery is probably something a should look for...

[booster]

I just checked the Safari website, which lists two 6v as standard, and didn't see any optional beyond that, so it is likely 195ah of 12v, which is not a lot if you are offgrid with a compressor frig, and want to stay within the (questionable, maybe) 50% discharge rule. A family of 5 is also going to use more power than one person or a couple.

The 270 watts of solar will probably get you 80-90 amp hours per day in good sun, closer to 1/2 that in the very low sun times, and maybe a quarter of that in the shade, so you would stand a chance on breaking even on good sun time, but wouldn't have much reserve for rainy periods, and would have to find shore power or run the engine after a day or two. It would be interesting to find out the wire size and breaker sizes in the cable from the alternator. The batteries would probably accept over 100 amps if pretty low, maybe 120 amps depending on the voltage drop from the engine. It could also be breakered at 80 amps so they could use 4ga wire, like many B's do.