Advancing Alvar

[wincrasher]

If the portable units are any indication, they are. One I looked at today said 15 amps. Couple that with a microwave at around 12 amps, and you are looking at some serious power for just cooking.

That's partly why I'm just not a fan of this all-electric concept. I think it certainly adds complication and you could end up with a lot of battery anxiety, or at least constant monitoring.

I think you could take some of the concepts, coupled with older technologies, and make a coach that can stay unplugged for a very long time, with or without solar.

I'd not abandon propane. It's a cheap fuel and offers a lot of advantages. I also like the idea of the alternator/generator thing you can get on the diesel MB. If you can run the A/C off that, then you could get by without a LP generator. So big battery bank, propane cooktop and oven, 3 way absorption fridge. Diesel heat and water heating. No LP generator. 200 watts of solar. 18 gal LP tank. Can all that fit?

[booster]

Originally Posted by wincrasher

If the portable units are any indication, they are. One I looked at today said 15 amps. Couple that with a microwave at around 12 amps, and you are looking at some serious power for just cooking.

That's partly why I'm just not a fan of this all-electric concept. I think it certainly adds complication and you could end up with a lot of battery anxiety, or at least constant monitoring.

I think you could take some of the concepts, coupled with older technologies, and make a coach that can stay unplugged for a very long time, with or without solar.

I'd not abandon propane. It's a cheap fuel and offers a lot of advantages. I also like the idea of the alternator/generator thing you can get on the diesel MB. If you can run the A/C off that, then you could get by without a LP generator. So big battery bank, propane cooktop and oven, 3 way absorption fridge. Diesel heat and water heating. No LP generator. 200 watts of solar. 18 gal LP tank. Can all that fit?

I wouldn't get rid of the propane either, for similar reasons. I could imagine a "clean" kitchen, though. Why not get rid of the stove, and maybe even the microwave, and just have a propane connection. With proper design of the appliances, you could use the same cooking burner and oven/grill indoors or outdoors. I wouldn't have the absorption frig, though.

There have been a lot of thoughts about the engine generator running the AC, even ignoring the MB idling rules. The recurring question to me is why would you generate DC electricity, run it through a huge inverter to get 110v AC, and then run an 110 v AC air conditioner, when all you would have to do is run the van dash air conditioner and save all the wasted inefficiencies. We can do that right now with our gas powered Roadtrek 190.

[Mike]

I think my preference for on board, off grid, power systems has always been maximum redundancy. Some power sources are just better suited to different applications in an RV. With something else there as a backup strategy, as/if required.

[mlts22]

I hope I'm not digressing too far here, but I like the concept of electric appliances, all power coming from the batteries directly or via an inverter, then various power inputs to the batteries, be it an alternator, an onboard genset, solar, or good ol' shore power. The advantage of this is that all power to the devices will be extremely clean, no matter how dirty the incoming power is (well, clean until the batteries don't have enough charge to maintain the outgoing amperage.)

Of course, fuel cells, when they come down in price from the stratosphere, will help as well. Truma's VeGA uses propane, but is only available in the US on the gray market, and for near the five digit range. EFOY's fuel cells use methanol, but prices start at $3499 for a 40 watt version, going to $7000 for a 105 watt model, with a stop at 75 watts for five grand. Fuel cells won't run the A/C, but will help the solar charging system, especially at night.

On the other hand, I do like the idea of having different power sources and redundant devices, especially for heat in winter. For example, if 120VAC is not doable for an electric heater, the propane furnace is useful. If battery power is so low that it can't spin the duct fans, a Buddy heater attached to the propane line can still keep the rig habitable.

[Davydd]

We rarely use an inside cooktop. Preference is always to cook outside via various methods - Coleman camp stove, charcoal grill, Dutch oven, brat on a stick over a fire, etc. The induction cooktop will be stored away in a drawer when not in use. That's a plus for the countertop which is used 90% of the time for other than kitchen use. Induction cooktops may draw a lot of amperage but they are efficient and even when used they are used for a very short time. Same with a microwave at 3 minutes at the most it seems to heat soup. This to me is an overblown fear since common sense would dictate the use which is not obligatory in the first place.

We will have at least 4 lithium-ion batteries that can draw down 80% coupled with solar and the diesel engine with the 200 amp second alternator for any power emergency. Keep in mind the lithium-ion batteries efficiency is equivalent to almost 7 AGM batteries. The batteries with inverter allows use of all the 120V outlets, AC and appliances, especially the coffee maker, at ALL times without needing to run an Onan like generator or plug into shore power. Propane cannot provide that without running a generator. I might add those 4 L-I batteries weigh about 1/7ths those 7 AGM batteries (360 lbs difference), in addition elimination of the 125 lb generator and 80 lbs of propane - 565 lbs total. The solar panels are probably a wash or better in weight to the exhaust pipe, hangers, tanks, accessories of the eliminated propane and generator.

Yes, to the question can you have it all if you choose - the big battery bank, the solar and an LP generator with an LP tank. Advanced RV has built that kind of RV. I choose not to have any propane. Don't forget the the cabin heating and hot water is run off the diesel powered (not M-B engine, BTW) Espar heat exchanger that heats glycol solution to 190F. That gives you instant hot water anytime, efficiently.

On our spring trip to Texas and Indiana over 3 months we drew down our propane tank about 5 gallons and ran our generator 1/10 hour to demonstrate it and round off to 14 hours total in four years. We tour and camp very efficiently. We did camp with shore power more than we normally do on our last trip but we also managed 11 weeks to Alaska and back on one propane fill as well. What we will do is make our camping choices a no-brainer. It will make no difference whether we camp dry or plug into shore power. All systems will be equally usable ANYWHERE and ANYTIME. Keep in mind most campgrounds have generator restrictions to no use whatsover to limited hours.

[pattonsr]

Regarding the second 200 amp alternator, I wonder what voltage regulator is being used? Hopefully it is a marine like regulator with 3 stage charging. If you are driving all day, the second alternator is running and I worry about overcharging the Lithium batteries.

Mike N. says he will produce a video like he did for the Espar hydronic explaining the second alternator and regulator, but so far nothing has shown up.

[Mike]

Originally Posted by Davydd

All systems will be equally usable ANYWHERE and ANYTIME. Keep in mind most campgrounds have generator restrictions to no use whatsover to limited hours.

I wonder how long it will be before campgrounds will have to also restrict excessive engine idling, for the same reasons that they ban excessive generator use?
You should have no problem with most of your stuff if it all runs off the batteries, but you may be faced with similar restrictions on recharging your batteries if the main power source to recharge them is the chassis engine. I guess you can always use shore power to recharge, if you don't mind being tethered for the required amount of time to replenish to 100% or in some combination of continued touring and solar.
Food for thought?

[mlts22]

I didn't realize that lithium batteries have such a good energy density and weight benefit. My only concern is that they need special chargers that have to "know" about each other. With AGM batteries, I can have one MPPT CC for the roof panels, one MPPT CC for a portable array, and the RV's onboard converter, and they are all separate systems. If I tried that with lithium batteries, I'd probably have an explosion shortly thereafter, especially on hotter days.

[obgraham]

You can find a scenario where any RV configuration is less than ideal. You have to find the rig/setup that best suits what you want to do. In my case, we don't park up boondocked for days on end. We'll find our site, hopefully state parks and NFS or BLM campgrounds. Then during most days it's likely we'll be out in the B exploring someplace not too far away.

So by the time we get back to the CG in the evening, we've had plenty of chance to charge everything up, and hit the evening with a fully charged bank of batteries. Next day, repeat. Etc.

I'm thinking there will be few times that I'll need to use the engine generator in the idling mode. But it's nice to have it if needed.

Others use their rigs differently, and the same all-electric plan may not be practical. Get a different rig.

[Davydd]

I don't ever plan to have to idle my engine. That is but an emergency option in lieu of a separate propane generator. In my whole history of RVing (and you know my history, blah blah blah) there has never been an instance where I would have had to do so and that was with one and two battery wet cell systems. Don't forget, I'll also have 300+ watts solar in my arsenal while in a campground. But in such an emergency the Sprinter engine is considerably quieter than an Onan generator and wouldn't even be obvious to anyone considering there is no ban on driving or running your engine even in quiet hours that I have ever encountered. Besides, the 5th wheeler diesel pickup drivers will drown me out. You can recharge with shore power and you would obviously do so if camping with an electrical hookup. An electrical hookup would also take over any diesel Espar heating as that option is built in for shore power electrical to take over. You have solar, enuff said. And if you are a serious B van tourer (and why else would you have a B in my mind) your driving will probably take care of most of your charging needs.

I don't plan to avoid icing on the cake shore power camping. I could not have done so on South Padre Island for instance since every campsite on the island had electrical hookups. My haunts, Texas, Minnesota, Iowa, Wisconsin, Michigan and Indiana state park campgrounds mostly have electrical hookups. Hard to avoid. Any B socials or rallies we attend over consecutive days are all going to have electrical hookups. Surprisingly, going to Alaska and back with the exception of multiple night stays in Seward and Denali and a few other one nighters we had electrical hookups even on the Alaska Highway. The cream? National forests and BLM land. No problem. An overnight stay at a Walmart was never an issue or concern.

A lithium-ion battery weighs about 1/3rd of an AGM. We got to lift the equivalent amp hr batteries at Advanced Fest. It is significantly different. Also in power usage between lithium-ion 80% draw down to AGM 50% draw down you would need 7 AGMs to 4 lithium-ions for equivalent usage. I could put 7 of either underfloor in my B if I so chose. I'm not interested in nor do I think I'll ever have a need for separate systems that nee to "know" about each other but I suspect the next (Silverleaf) will take care of that.

The Silverleaf controller Advanced RV custom programs pretty much manages everything in the B. I can't pretend I know everything about it but they were demonstrating how they were managing lithium-ion batteries at Advanced Fest not just down to each battery but each cell for temperature and voltage. I don't have the details but I cannot imagine Advanced RV not having intelligent battery management. I know they are working on lithium-ion battery concerns no one else seems to be aware of.

I can't stress again, Advanced RV has demonstrated to me they are looking to provide the best they can or can find. Their bottom line is not to cut cost which pops up with Winnebago ERAs, some simple mystifying differences in Roadtrek CS and RS E-treks and marketing driven decisions by most all converters. I'm willing to pay for the best. My biggest fear is what I buy today, I'll groan tomorrow and wish I had waited because I don't think Advanced RV is going to sit on their thumbs. I feel that way right now with the 4x4 Sprinter coming out. But then there is 2019 and Mercedes Benz' next major Sprinter upgrade when I might be ready for my 4th B.

[mlts22]

I will go out on a limb and state that you will not be disappointed by Advanced RV. Winnebago makes the best bang for the buck rigs. Advanced RV makes the best Sprinter upfits on the market, bar none.

The Silverleaf Total Coach controller looks cool. I wish other RV makers would use it. We have connected computers and deadbolts on doors (well I don't, but I don't like using new tech for new tech's sake) that open with an iPhone app... so why can't more rigs have their EMS, generator, inverter, and other systems connected.

[booster]

With all the talk about power use , batteries, solar, etc., there is one overriding thing that isn't being mentioned. It doesn't matter how many batteries you have, you still must achieve energy balance, or you will eventually run out of power. Having 800AH of batteries and using 200AH per day, gives 3 days to 25% charge. So does 200AH of batteries and using 50AH pr day. The big thing comes in when you look at what you replace each day. 300 watts of solar may give 120AH (optimistically) per day under great conditions, and 1/4 to 1/3 that under bad conditions. With the smaller load, you would rarely not get recharged, but with the larger load you would never get fully recharged, using just the solar, and would need another power source or more solar.

Other sources enter in also, particularly the van charging system, but only if you use it. Just last week, we sat for 3 days without moving or starting the van in National Park campground with no electricity, and anticipate 3-4 days being very common for us in the future. What is still up in the air in my mind is how fast, and how well from a charging profile, the engine generators charge batteries. If they are just fixed voltage alternators, and especially if you can't turn them off, you could be pretty hard on the batteries. When we get our new high output alternator, which is very late, I will be testing how fast, and how thoroughly, it charges our wet cells. AGM would be faster than wet cells, but also more susceptible to overcharge damage. Again the energy balance. You need to know (not guess) how much you have to drive to replace what you have used. We read all the time about folks saying they drive X amount every day or 2 days, or 3days, so they have full batteries. Unfortunately, nearly all have never checked to see if the batteries are full or not. Most folks tend to overestimate, I think, how much they are getting from driving.

If you have 800AH of batteries, and are down 600AH, it is going to take a while to get that back, no matter which method you use.

So I guess what I am saying is that you need to both sides of the equation when you look at your system. It really doesn't matter how much power you use, or where you use it, or how many or what type of battery the power comes from. You still need to replace that power. Again, it doesn't matter where the replacement power comes from, as long as it shows up.

This is a simplification, as there are lots of peripheral issues like short charging and overcharging that are also around, but in a well matched system, everything will work better and longer. I am going to be very interested to see how the mega battery systems work out in real life,especially in the charge control and over and under charging.

[Davydd]

Booster,

I don't plan to have a mega battery system. At least I don't consider 4 batteries as such (400-440 AH). If 300 watts of solar will return you that 120 amp hours then I would venture to guess I would stay mostly fully charged if not driving around. Solar alone would take care of refrigerator, MaxxAir fan, furnace fan, TV, lights, Kuerig coffee maker, charging iPads and iPhones, etc. Keep in mind none of that is continuous use with the exception of the refrigerator. I've never drawn my batteries down that much in a day ever. It really gets back to air conditioning and whether you use it and I am resting on my track record and common sense in that regard. Actually, when the day comes that I travel and sit on my ass inside an RV with the air conditioning running all day is the day I'll need a Class A with a toad. That day will never come. Hello condo rental.

PattonSR touched on it and you too in regard to the charging alternator. I'm not sure how that works. I am assuming there should be or is a smart controller involved. That I'll have to find out.

[booster]

The 120AH is under ideal sun. You could be as low as 40AH I think. We have been monitoring ours on the ongoing shakedown trip we are on, and with the compressor frig, moderate to cool weather, maybe a dvd watched, furnace overnight, charging up stuff, and a few led lights, we are at about 60AH per day. With 200 watts of solar, we could recover by noon in good sun (the recovery needed was in the 30AH range after overnight), but in poor conditions we wound up about 30AH short for the day.

This use is also with no inverter running 24/7, which could easily add 25+AH of use, even if just idling, depending on the inverter. Also no microwave, coffemaker, toaster or electric cooktop runs. It is very easy to get yo 100+AH of use per day, from what we have seen. Even just charging the laptop and tablet can use 5-10AH.

It all depends on how you are going to use the van. It all boils down to having enough battery plus solar to get you through how long you will be off grid, in poor conditions. Then you need enough solar plus other charge methods to recover the deficit in the batteries in a manner you can live with.

[bobojay]

I'm learning a bunch here just following the conversation. Booster, knowing how DavyDD & wife operate, they are not going to have any issues with not enough recharging during the day.

I'm familiar with how the second high output alternator/generators work on firetruck & ambulances I've been around, but they are way more heavy duty and higher output than what's on these RV's, and not very "smart" setups.

It fascinates me how Advanced and to a much lesser extent, the Roadtrek E-Trek second smart charge alternator works in the whole scheme of things

[booster]

It fascinates me how Advanced and to a much lesser extent, the Roadtrek E-Trek second smart charge alternator works in the whole scheme of things

I think that is the question. Is there a smart charger in the alternator circuit? The basic etrek wiring drawing that was posted here didn't show a charger in either the 12 or 24 volt engine charging circuits. No manufacturer that I know of uses a charger in the alternator circuit, or even a disconnect. We don't know if Advanced adds one yet-I hope they do.

Davyyd is probably the outlier in the group of folks that buy this type of B, as he moves around a lot, historically hasn't used lots of power, and very well may keep up just fine. What my comments are directed to are the multitude of time we see folks, or manufacturers, talking about boondocking for long periods, using all the appliances off the batteries, and then thinking that 245 watts (Roadtrek), or a trip to the grocery store driving, is going to refill their batteries. We also don't know how the manufacturers are handling, or are going to handle, the interactions between the various charging methods. My guess is that there are going to be a lot of "growing pains" as these systems get more popular, and we all find out how well they work in everyday situations. We are close to entering our 3rd week of real world testing on our new setup, and the things we have learned are very interesting. I will be putting up some results soon, but I am convinced that with good components and controls (some may not exist yet), off grid time, battery life, and versatility can all be greatly improved over what is currently available. I hope we see some, or all of these kinds of features in Davyyd's Advanced RV.

[gerrym51]

I know i've said this before-so i'll say it again. Unless you are truly unique-most(if not all) b owners don't stay in same spot for very long. you will start and move your B if not every day then every 2 days(i'm sure now someone will say they did not move for a month-then why a b?-trailer would make more sense).

worries about batteries/solar panels etc make little sense.

people who are boondockers and stay in same place for long periods of time are usually not B owners

A B is a moving hotel room

[Davydd]

Just to recap battery charging options.

Driving charges auxiliary batteries. Every B has that.

Shore power charges auxiliary batteries. Every B has that.

Solar charges auxiliary batteries. Only when parked?

A generator be it gas, diesel or propane charges auxiliary batteries. This is what I am eliminating.

Fast idling the Sprinter engine charges the auxiliary batteries. This method is good for 3 hours then it is recommend you drive for about 40 minutes between idling intervals. Some claim and it was discussed at Advanced Fest in front of Mercedes Benz you can idle up to 10 hours but to be safe, but stick with M-B recommendations.

I'm not sure why the second 200 amp alternator when I thought the Sprinter's 220 amp M-B engine alternator was charging auxiliary batteries in Bs. The reason I can think of, and I hope, is that this method affords you to install some kind of intelligent charging circuitry that maybe you could do off your engine alternator. Unresolved question.

Autostart engine backup controlled through Silverleaf (I believe) will come on if batteries get too low. My understanding is auto running the engine will then again turn off after two hours. The keys don't have to be in the ignition and the van can be locked. If someone tried to drive off, stepping on the brake to engage the transmission will turn the engine off.

Monitoring can be achieved through a smartphone app.

[Davydd]

Originally Posted by gerrym51

I know i've said this before-so i'll say it again. Unless you are truly unique-most(if not all) b owners don't stay in same spot for very long. you will start and move your B if not every day then every 2 days(i'm sure now someone will say they did not move for a month-then why a b?-trailer would make more sense).

worries about batteries/solar panels etc make little sense.

people who are boondockers and stay in same place for long periods of time are usually not B owners

A B is a moving hotel room

That is my experience with one and two battery Bs. With one battery management was very critical but I still managed to dry camp in one place 5 straight days. With two batteries it has not been critical but there are limitations in the use of the B with appliances and outlets. It is the full use of the B I am seeking with that anytime and anywhere concept. Now the limiting factor in seeking amenities and services is for dumping, refilling, laundry and groceries. With a 40 gallon fresh water tank, 26 grey and 18 black I am pretty sure we can extend our historical average of 4-5 days to over a week. I think we currently have 29 (+6)/20/11 gallon tanks. If I were alone I could easily go two weeks or as long as the beer lasts because I don't have to wash my hair every single morning like someone I know.

A trip up the Gunflint Trail to a national forest campground is now a total no-brainer free of management worries for the most part. We will even have a bigger refrigerator.

[pattonsr]

Mike N. needs to produce a video like he did for the Espar Hydronic to fully explain how Advanced RV will charge the large battery bank, whether Lithium or AGM.

My understanding is that he wants to use the MB bracket that is a factory option for both 4 and 6 cylinder engines. A quiet second alternator will be fitted and what happens after that we can only guess at.

If going direct to the battery bank, an external regulator like a Balmar will be needed to provide crude 3 stage charging. I ran across an article where a cruising boat owner modified the Balmar charging stages to more fully charge the battery bank. The Balmar is very crude compared with an Outback or Magnum charging routine.

The other approach is to feed the alternator output to a control box that inverts the 12v and provides as output pure sine 120v. The 120v is feed to the transfer switch just like a generator. This basically is how a Honda inverter generator works. This approach lets the Outback do the charging whether from shore power or engine driven generator. I believe this is the best approach.

However Advanced RV may have designed an external regulator that is capable of 3 stage charging that is better suited than a Balmar. Lifeline AGM requires different settings than Lithium. Lithium is actually easier to charge since they do not require a full charge like AGMs. If the 2 hour window gets the Lithium bank back to 80% that is ok. If a Lifeline AGM is brought back only to 80% due to the long generator time to reach 100%, then the Lifelines will have a short life.

The key problem is not to overcharge AGMs or Lithium. Both Magnum and Outback provide shunt based battery monitors that will allow seeing all energy going in or out of the batteries. It doesn't matter what the energy source is (solar, shore, generator, etc.).