Advancing Alvar

[Davydd]

Originally Posted by gerrym51

I like reading technomadia but i have found when you read the articles is important. technology moves too fast. taking a technomadia article thats more than 6 mos. old as gospel is a mistake.

Do you have newer information that makes this article a mistake?

[gerrym51]

Originally Posted by Davydd

Do you have newer information that makes this article a mistake?

actually no Davydd. i have read many technomadia articles covering a variety of subjects. some when i read them were outdated. but i have no specific info on this particular subject. i was mostly investigating routers.

[pattonsr]

Technomadia is now reveiwing flat solar panels along with the GS-100 from AmSolar..

http://www.technomadia.com/solar/

Their bus roof is curved so the newer flat panels were of great interest. Note that there are two further articles at the bottom of this overview article.

If one wants to look at all of the articles on lithium, go to

http://www.technomadia.com/lithium/

Now they are focused on solar. I can't wait to see the results.

[Davydd]

If you dig into the lithium battery Technomadia article you come upon this linked PDF reference:

DIY Lithium Iron Phosphate Batteries (LiFePO4) for Marine Applications

In that PDF article the author states, "There were only 2 simple BMS [Battery Management Systems] systems I considered. The Elite EMS and Clean Power Auto's HouseBMS." The author chose the Elite EMS because it could monitor more information and the same information Advanced RV says they are monitoring and controlling - one was cell temperature. Advanced RV had the Elite EMS up and running at Advanced RV Fest & Open House so I suspect by process of elimination they may be using it and they say they have completed actual coach testing.

The critical thing Elite EMS does is monitor each cell for temperature as bulk charging lithium batteries in below 32 deg. F. temperatures will damage them and permanently reduce battery capacity. At Advanced RV Fest they were working on insulated battery boxes with supplied heat. They mentioned too, their power system will automatically make sure cell temperatures are above freezing when charging is required. My understanding is a charged lithium battery will still provide power with no problem, but the bulk recharging of a depleted battery in freezing weather would be the issue. Their system would monitor each and every cell individually "in temperature, input and output accounting for an accurate state of charge, with a recalibration at full charge and true array equalization for charge/discharge", and shut off charging if below freezing. If they can keep the batteries above freezing they could still be charged. I would normally never attempt to be out at that temperature but here in Minnesota we do store our RV at that temperature and colder so would hope by keeping it plugged in to shore power as we do we'll have a heated battery box to keep the temperatures above freezing and the batteries charged. Advanced RV confirmed the heated battery box installation. I also learned the damage is from bulk charging not float charging.

I wonder if Roadtrek knew any of this when they first said they would use lithium batteries in their E-Treks but later backed out.

[Davydd]

The flex solar panels are of interest as I believe weight would be lighter, better potential for stealth appearance, and of course, just general aesthetic appearance in possibly being hidden from view. The Sprinter van roof is deeply ribbed so I am not sure if a flex panel would make any sense without some kind of stiff backer panel but then you are also back to traditional panels. The Technomadia people have a bus with a smooth arched roof. It would make a lot more sense there.

[pattonsr]

Davydd,

The boat article was very detailed. If you go to the main lithium link for Technomadia you can see all of the Technomadia articles on how they got started and all of the research they did. I first got interested in boosting inverters after reading their article on it.

If one drops in a Smart Battery the work is done for you which is the approach Advanced RV first used. But the cost is approximately 3 times greater than the do it yourself bleeding edge. It does look like Advanced RV is going the same direction as Technomadia which makes large Lithium banks much more affordable.

You mentioned Advanced RV is still deciding on the best solar panels to use. I would imagine they will be interested in what Technomadia finds out from their testing. I would expect their test results to be out very soon.

[Davydd]

Technomadia is testing flex solar panels, the frameless glue down type on smooth roofs. I don't know if that information will help for a ribbed roof Sprinter as I just mentioned above. Can you install a flex solar panel to follow the ribs? Are they that flexible? And if you can, would it be practical?

Early on they stated their standard was two 95 watt panels and that is still on their website. Mzungu, their proof of concept ecOasis B has much more and I believe 500 watts. The other RV roof they show I think might be two 160 watt panels. They look like they match the AM Solar panel of that size. Advanced RV said they are still looking at other solar panels. I don't know if they need to wait for Technomadia.

From standing on the ground you really barely can tell there are solar panels on a Sprinter roof.

[pattonsr]

On the Sprinter forum there is much interest in mounting flexible panels. The Sprinter ribs do allow airflow underneath versus a flat roof. The rise in temperature when flexible panels are attached directly to a flat roof is one of the issues which I believe Technomadia will answer. Remember their testing includes a traditional GS-100 from AmSolar.

I have not seen any testing of flexible panels versus the claims of the vendors. Less weight but probably less bang for the buck. We shall see.

Mike N. always told me that they will find something that will exceed a GS-100 panel from AmSolar. I would be happy with as many GS-100 or GS-135 that will fit with the space remaining on the roof.

.

[tinman22]

Originally Posted by Davydd

Technomadia is testing flex solar panels, the frameless glue down type on smooth roofs. I don't know if that information will help for a ribbed roof Sprinter as I just mentioned above. Can you install a flex solar panel to follow the ribs? Are they that flexible? And if you can, would it be practical?

Early on they stated their standard was two 95 watt panels and that is still on their website. Mzungu, their proof of concept ecOasis B has much more and I believe 500 watts. The other RV roof they show I think might be two 160 watt panels. They look like they match the AM Solar panel of that size. Advanced RV said they are still looking at other solar panels. I don't know if they need to wait for Technomadia.

From standing on the ground you really barely can tell there are solar panels on a Sprinter roof.

I am very interested in using solar panels. Is there current information concerning weather damage, and increased damage from air pressure created during driving. How does Advanced warranty them?

[stanw909]

I have a 95 Bounder that the original owner installed in 96.They are the old rigid glass panels and work great . I don't know at what miles on the odometer it had when they were installed but the rig currently has 83,000 miles. I have heard of reliability issues with the flexible panels but am considering for my new to me 96 Saratoga. I hope they've improved because with my roof style and shape , I don't see a way to add rigid panels.

[Davydd]

Originally Posted by tinman22

I am very interested in using solar panels. Is there current information concerning weather damage, and increased damage from air pressure created during driving. How does Advanced warranty them?

tinman22,

Solar panels with any Class B company is a third party add-on just like an Onan generator, Dometic refrigerator, Air-conditioner, etc. So, I assume a shared warranty like those products and in line comparable to everyone else. ARV would be responsible for the mounting integrity I would think. Weather damage? I would guess that would be a limited warranty depending on how the weather damage is defined and that would be the panel manufacturer. Solar panels are a fast changing technology and market. It seems companies come and go, and there always seems to be something better coming along. Your best warranty is your own due diligence, IMO. As for Advanced RV, to be honest, I couldn't tell you typing here off the cuff. I would have to do what you can do and that is to check their web site or ask them. Right now I am going on faith they will back their product and so far they have done so with their customers. I also subscribe to their philosophy that anything they put into their Class Bs is based on what's best at the time and not what's best to cut cost. There is no dealer middle man involved in this. So, in my mind, the warranty is faith, a handshake, and philosophical partnership with Advanced RV.

[stanw909]

Davydd. Does Advanced rv send you any progress pics like Sportsmobile?

[Davydd]

They said they would but all I have so far is a raw cargo van. I'll be there next week to see that for myself.

[markopolo]

Originally Posted by tinman22

............. I am very interested in using solar panels. Is there current information concerning weather damage, and increased damage from air pressure created during driving. How does Advanced warranty them?

Just a general comment re: solar panels on RV's. One of the Solar Panels on my van was purchased in 1994. I have the receipt for the 40 watt solar panel "kit". My van is a 1997 but the guy that built it used lots of parts from his previous van. I should test the output of that 20 year old panel some time. Maybe next summer.

[Davydd]

This my analysis and reasoning for determining the electrical requirements for Alvar. The goal is to be able to tour and not have to consider each day whether to dry camp or seek an electrical hookup service. We would also have access and full function for everything electrical in our Class B at all times like the 110V outlets, coffee maker, microwave, etc. and even air conditioning. Lastly, we desire to eliminate all propane and a propane generator. It appears a lithium-ion 400 amp battery bank and 300 watts solar would be the most appropriate combination to satisfy that goal. Advanced RV had proposed that but I wanted to work it out for my own satisfaction. Based on our historical usage we are being generous on the high side of usage in our calculations.

Calculating RV Electrical Use

Required Daily Use:
1 amps x 24 hrs = 24 amps - Miscellaneous (alarms, monitor lights, standby, etc.)
1 amps x 8 hrs = 8 amps charging electronics
5 amps x 2 hrs = 10 amps - Lights
5 amps x 18 hrs = 90 amps - Refrigerator*# (5.2 amps when running)

Required Daily Use Sub Total: 132 amps

Anticipated Required Daily Use:
5 amps x 2 hrs = 10 amps - More lighting if not traveling
125 amps x 0.5 hrs = 62 amps - Coffee Maker
1.5 amps x 4 hrs = 6 amps - Ceiling fan

Anticipated Daily Use Sub Total: 78 amps

Anticipated Additional Campground Use:
7 amps x 4 hrs = 28 amps - Laptop Computer
7 amps x 3 hrs = 21 amps - TV

Anticipated Additional Campground Use Sub Total: 50 (rounded off) amps

Optional Voluntary and Occasional Campground Use:
150 amps x 0.5 hrs = 75 amps - Induction Cooktop
75 amps x .25 hrs = 19 amps - Convection/Microwave Oven (900 W)
17 amps x 2 hrs = 34 amps - Crockpot
Most likely a max of 100 amps would be used in combination of the three cooking options. We are eliminating the propane cooktop. We will still carry charcoal and an outdoor Coleman propane stove for our preferred outdoor cooking.

Total Daily and Anticipated Use: 260 amps

Heavy Use Total (Required, Daily, Anticipated & Optional): 360 amps max

Air Conditioner: 125 amps per hour of use. Not anticipated other than very sporadically with historical Class B touring habits following seasons and weather, and could be used during a daytime driving stop if then.

On driving days 400 amps battery bank seems more than ample even without solar panels. One could run an air conditioner for a pet during a 1-2 hours lunch stop or event.

When dry camping 300 watts of solar producing 90 amps would mainly equalize the refrigerator usage. Compared to our historical use we could dry camp up to about 3 days without driving or even idling the engine (equivalent to Onan generator charging.)

400 amps battery bank would be sufficient. 600 amps battery bank would be more than needed. There would be no need for an Onan propane generator or propane.

Reference and Supporting Criteria:

Just to keep in my head: Amps = Watts/Volts (120 AC) x 10 to convert to 12 volts or just: Amps = Watts/12 DC

Advanced RV Lithium-ion Battery Options:
400 amps Lithium-ion batteries drawn down 80% = 320 amps usable
600 amps Lithium-ion batteries drawn down 80% = 480 amps usable
800 amps Lithium-ion batteries drawn down 80% = 640 amps usable

Advanced RV’s high idling parked or driving would replenish 300 amps in an hour with the second under hood alternator. You can idle as much as 3 hours but then you would have to drive for 35-45 minutes between idling periods.

Advanced RVs proposed Outback 2800 watt pure sine waver inverter is enough to power all electrical in a dry camping situation.

Advanced RV uses an Espar diesel hydronic heater and hot water further reducing the need for propane.

Advanced RV has an Autogen feature that will start the Sprinter and run a maximum of 2 hours if low batteries are detected. In theory it would take about an hour to charge the batteries.

Rule of Thumb: A 100 watt solar panel produces an average of about 6 amps per peak sun hour, or about 30 amp-hours per day over a 5 hour optimum period. 300 watts would provide 90 amps. It could be higher or it could be less.

History: With our current Great West Van Legend we have a total of 14 hours on the Onan generator over four camping seasons, over 350 nights camping and 65,000 mile driving. We probably have used our air conditioner less including time when plugged into shore power.

With back door screens combined with side sliding door screen and 5 operable sreened windows the van can equalize with the prevailing temperature and be comfortable up to 90F in low humidity conditions, i.e. tent camping like toughing it out with no air conditioning.

[markopolo]

Originally Posted by Davydd

This my analysis and reasoning for determining the electrical requirements for Alvar. The goal is to be able to tour and not have to consider each day whether to dry camp or seek an electrical hookup service. We would also have access and full function for everything electrical in our Class B at all times like the 110V outlets, coffee maker, microwave, etc. and even air conditioning. Lastly, we desire to eliminate all propane and a propane generator. It appears a lithium-ion 400 amp battery bank and 300 watts solar would be the most appropriate combination to satisfy that goal. Advanced RV had proposed that but I wanted to work it out for my own satisfaction. Based on our historical usage we are being generous on the high side of usage in our calculations.

Calculating RV Electrical Use

Required Daily Use:
1 amps x 24 hrs = 24 amps - Miscellaneous (alarms, monitor lights, standby, etc.)
1 amps x 8 hrs = 8 amps charging electronics
5 amps x 2 hrs = 10 amps - Lights
5 amps x 18 hrs = 90 amps - Refrigerator*# (5.2 amps when running)

Required Daily Use Sub Total: 132 amps

Anticipated Required Daily Use:
5 amps x 2 hrs = 10 amps - More lighting if not traveling
125 amps x 0.5 hrs = 62 amps - Coffee Maker
1.5 amps x 4 hrs = 6 amps - Ceiling fan

Anticipated Daily Use Sub Total: 78 amps

Anticipated Additional Campground Use:
7 amps x 4 hrs = 28 amps - Laptop Computer
7 amps x 3 hrs = 21 amps - TV

Anticipated Additional Campground Use Sub Total: 50 (rounded off) amps

Optional Voluntary and Occasional Campground Use:
150 amps x 0.5 hrs = 75 amps - Induction Cooktop
75 amps x .25 hrs = 19 amps - Convection/Microwave Oven (900 W)
17 amps x 2 hrs = 34 amps - Crockpot
Most likely a max of 100 amps would be used in combination of the three cooking options. We are eliminating the propane cooktop. We will still carry charcoal and an outdoor Coleman propane stove for our preferred outdoor cooking.

Total Daily and Anticipated Use: 260 amps

Heavy Use Total (Required, Daily, Anticipated & Optional): 360 amps max

Air Conditioner: 125 amps per hour of use. Not anticipated other than very sporadically with historical Class B touring habits following seasons and weather, and could be used during a daytime driving stop if then.

On driving days 400 amps battery bank seems more than ample even without solar panels. One could run an air conditioner for a pet during a 1-2 hours lunch stop or event.

When dry camping 300 watts of solar producing 90 amps would mainly equalize the refrigerator usage. Compared to our historical use we could dry camp up to about 3 days without driving or even idling the engine (equivalent to Onan generator charging.)

400 amps battery bank would be sufficient. 600 amps battery bank would be more than needed. There would be no need for an Onan propane generator or propane.

Reference and Supporting Criteria:

Just to keep in my head: Amps = Watts/Volts (120 AC) x 10 to convert to 12 volts or just: Amps = Watts/12 DC

Advanced RV Lithium-ion Battery Options:
400 amps Lithium-ion batteries drawn down 80% = 320 amps usable
600 amps Lithium-ion batteries drawn down 80% = 480 amps usable
800 amps Lithium-ion batteries drawn down 80% = 640 amps usable

Advanced RV’s high idling parked or driving would replenish 300 amps in an hour with the second under hood alternator. You can idle as much as 3 hours but then you would have to drive for 35-45 minutes between idling periods.

Advanced RVs proposed Outback 2800 watt pure sine waver inverter is enough to power all electrical in a dry camping situation.

Advanced RV uses an Espar diesel hydronic heater and hot water further reducing the need for propane.

Advanced RV has an Autogen feature that will start the Sprinter and run a maximum of 2 hours if low batteries are detected. In theory it would take about an hour to charge the batteries.

Rule of Thumb: A 100 watt solar panel produces an average of about 6 amps per peak sun hour, or about 30 amp-hours per day over a 5 hour optimum period. 300 watts would provide 90 amps. It could be higher or it could be less.

History: With our current Great West Van Legend we have a total of 14 hours on the Onan generator over four camping seasons, over 350 nights camping and 65,000 mile driving. We probably have used our air conditioner less including time when plugged into shore power.

With back door screens combined with side sliding door screen and 5 operable sreened windows the van can equalize with the prevailing temperature and be comfortable up to 90F in low humidity conditions, i.e. tent camping like toughing it out with no air conditioning.

Seems pretty well thought out to me. The microwave might draw more. They usually have two ratings: cooking watts and power usage watts. A 600w (cooking) might have a power consumption rating of 900w. 900w cooking might be 1200w power consumption. The run-time duration is not long though so it might not impact your calculations much.

Booster has previously mentioned an excellent point about choosing to charge items like your camera, laptop or phone etc. when you have surplus power coming in either from the solar panels or when driving. It's free power if it is surplus.

The Air Conditioner start-up power requirement can be quite high for a very short duration. I assume Advanced RV has already tested the combination of your particular A/C unit model and the Outback inverter.

Is it possible to have a place ready to add 200ah more battery capacity if ever needed? You do have the ability to quickly charge the battery bank and no point in wasting space or money and you might never need to actually add extra capacity but it would be nice just to have space in the right place for it.

[markopolo]

Also, the convection option on the microwave oven would have a much higher current draw if used. I had one in my Trail-Lite and it was on a 20amp 120v plug. It would probably have been 2000 watts or so in convection mode.

[Davydd]

Marko, All good points and I hope to get some feedback on that this week from Advanced RV. I was being liberal with my requirements. Actually, we charge our iPhones and iPads while driving most of the time through 12V connections. It is computers that always had to have a shore power connection and they too could be charged while driving now.

I gave the microwave 15 minutes. Heating water for tea is really about a minute. Cooking a hot dog 1 minute. Popcorn 3 minutes. Rejuvenating a Krispy Kreme donut 5 seconds. I kind of doubt we'll use our microwave much. We never have. I do need to check the convection oven part for baking but suspect we'll use that when hooked up to shore power if we are going to bake something like bread for 45 minutes. We have used our crockpot a few times while driving down the road. I don't know a lot about the induction cooktop but understand it is more efficient and faster than other cooking methods in that you get instant temperature and have pretty good control.

The air conditioner should work as I surmised. I found out that a Roadtrek E-trek with 800 amps of AGM batteries has been tested to run 4-1/2 hours continuously. I should be able to get the 2 hours that I want with the lithium-ion batteries.

We still do a lot of camping with electrical hookups. Most state parks in the upper Midwest have electrical hookups as does Indiana, Texas and Louisiana where we have spent our last two springs. Whenever we have gone to rallies and socials it seems they have all had electrical hookups. Consensus of a group of RVers requires it. What I want to eliminate is the need to have to seek them. It would help when we visit our daughter in Virginia and our son in Wisconsin where we can't plug in. We probably could operate on 200 amp hours of batteries if we had to. We've been doing that very thing with less efficient lead-acid batteries if the solar can balance out the compressor refrigerator. Our propane generator use over time has been mostly testing and exercising and running 110v AC for morning coffee. while driving we couldn't deplete our batteries with a second alternator charging at 300 amps. I can't see anticipating using the Autogen start or engine idling to charge batteries much if at all. It is just a comfortable backup.

The independence key is continuing our traditional touring and never relying on air conditioning. I doubt we would ever head south in the summer time. The past two years we did get caught up in Kansas 95F and 100F heat. That was to go to BEE Socials and we had electrical hookups of course. Unless we all of a sudden become profligate energy users I am not too worried.

As for space for additional batteries, I suppose it could be planned for. It is all below the floor. I will have three basement storage compartments I believe and I don't think I would want to give them up. Also I'm not sure how the battery configurations will work. I believe these will not be discrete batteries like the Smart Li-on battery that is basically the same size and hooks up the same as an AGM battery. I think they will be assembled cells.

[booster]

The numbers look to be well thought out, but I would not use the 90 amp hours of power from 300 watts of solar, especially since you are looking at not having much more than 1 days use worth of battery bank. If it is cloudy, you are in deficit in one day, with no cushion to wait for the sun. We are sitting Acadia national park right now, and on a cloudy drizzly day, at this latitude, our 200 watts of "good even in the shade and clouds" solar was barely over 10AH.

Personally, if I had a clean slate like you do, I would want at least 3 days of battery capacity, and as close to 1 watt of solar per AH of capacity that I could get, especially since you are looking at wanting 3 day of off grid capability. IMO, idling the engine is just as distasteful as running a generator, just not for as long a time.

[Davydd]

Booster, my suspicion is we could easily go 3 days on 400 ah li-ion batteries because we most likely would be ignoring Internet and TV and would be campfire cooking most of the time in places that would be conducive to stay like Trails End CG on the Gunflint. This exercise tells me more than anything that solar on a flat roof not aimed is not that contributing. The most you could probably get on an extended body Sprinter would be in the neighborhood of 500-600 watts. That Advanced RV Mzungu concept B had 500 watts and they have published photos of that roof. So I am not sure you could get 3 days solar capacity especially in a northern Minnesota woods. The solar will contribute while driving but if the second alternator contributes 300 amps charging the solar would not be needed. Oh well, maybe in Quartzite, AZ this February it might perform.

The saving grace is that even when parked for 3-5 days at one campground we normally still drive around going to visit restaurants, stores, scenic locations and drives, and trailheads just about daily. That is pretty much how we got 5 days at Swiftcurrent CG in Glacier NP with two lead-acid batteries and no solar or generator use.