Advancing Alvar

[wincrasher]

Well, knowing the numbers games Roadtrek likes to play, I doubt 1600Ah is at 12volts.

But regardless of whether it's truly 1600 AH as we would expect, dimensionally that size of a pack would be hard to fit. What are the dimensions on such a pack, and where would it go? Would it be more than one volume - maybe two or more smaller packs?

I do agree with the last post - a true fuel cell is the way to go. Compact and can generate significant power. Solves alot of problems, but not of cost unless there is a huge breakthru.

Back in the day, Musk said that the future is capacitors. He wanted to develop one that would replace batteries. But so far, nothing.

I do think we are close to a turning point on the Lithium batteries though - when these giga-factories are up and running, we'll be swimming in much cheaper lithium batteries. The window of a $26k option will close pretty quickly - I'd bet that this is a $3k option, or just a standard feature in 3 to 5 years.

[avanti]

I totally agree with the "swimming in lithium" comment. Although there are still challenges in bringing down base material costs, bringing production to scale will make a huge difference and Elon has caused this to be pretty much done deal. I believe that prices will soon tumble. When I replace my almost-new batteries, I strongly suspect that I will replace them with inexpensive lithium.

I'm less convinced about fuel cells, though. Not so much on technical grounds (a breakthrough is quite possible), as on political grounds. Although big oil very much wants to preserve a centralized infrastructure-centric energy system, people are starting to glimpse the advantages of a more decentralized, peer-to-peer energy architecture, and batteries make much more sense in such a world than fuel cells (There are scenarios that contradict this, e.g., solar production of hydrogen, but they are currently not very convincing). Batteries have a lot more momentum and thus funding, and kids are really pushing in this direction. I think they are going to win. I wouldn't be sad if viable fuel cells showed up as an alternative, but I am not betting on it.

[wincrasher]

I'd agree if we were talking hydrogen fuel cells. But the development I've been reading about seems to always be LP fueled fuel cells. LP is a product of big oil. So that could change your equation a bit.

[avanti]

Actually, I was not assuming hydrogen. That is starting to look like a non-starter--too difficult logistically. Yes, if fuel cells happen, it will be precisely because big oil wants it to, and I don't underestimate their power. I just don't think they are on the right side of history. We'll see, I guess.

[Boxster1971]

Originally Posted by pattonsr

Where is Roadtrek putting the 1600 AH lithium? Are they mounted underneath and how are they protected from freezing weather?

Who knows - and if you try to ask Roadtrek, Jim Hammill, Mike W or Campskunk they will tell you it is proprietary "need to know" information. Roadtrek takes very serious efforts to protect their R&D investment.

[Davydd]

Originally Posted by pattonsr

Where is Roadtrek putting the 1600 AH lithium? Are they mounted underneath and how are they protected from freezing weather?

Last winter Roadtrek showed a teaser video about lithium ion and this is a capture of the lithium ion battery banks they panned over in that video. They look like steel trays with 8 battery cells. The trays look as if they would have latches that would attach underneath. They could do banks of batteries and install them in modules I would think. There would be space I think behind the rear axle to get enough battery power they claim. I also think it would be a 12V system made up of 3.2V cells. Four cells would be wired in series to create 12V modules. They look like Lithium Prismatic Batteries and if each cell is a 200ah battery they could get their 1600ah with four of those trays. One tray for 400ah and two trays for 800ah.

How do they protect them from freezing weather? Who knows? Technomadia did not have any way to monitor the temperature of the cells the way Advanced RV does and had no method that I am aware of other than staying out of freezing weather or keeping them in a conditioned space. This video snap hints at nothing but that doesn't mean they haven't kept developing.

What we do know is there are two lithium ion battery Roadtrek CS Bs on the road. So they've done it. We do know Mike Wendland took his to Tahquamenon Falls in Michigan's UP to winter camp in below freezing temperatures in January. They had shore power there. Still, shore power would attempt to charge batteries and that is not good unless they heated them or disconnected them when plugged into shore power. But as Boxster1971 said, it is proprietary.

[booster]

Roadtrek has traditionally cut the floor and loaded the batteries into fixed trays from the top, from all the pix of the other big bank units I have seen. I would expect them to just use the same system for lithium. The latches on the boxes in Davydd's picture look to be the standard electrical box cover/door latches that they use on watertight electrical and control boxes. They hook over a flange on the cover and tighten with a screw. The would be no where near strong enough to hang a battery box on.

We know Roadtrek went through a lot of versions of the large battery bank models trying to get things right. We also all know very well about exaggerated performance claims and deceptive ways to list specs to make them look better eg 400amp battery that is really 180ah. All the other brands are proud of their designs, too, and happy to explain why they are good, so to me, proprietary is kind a put off, and definitely not a plus.

I hope they get the lithium done well, for the good of the entire industry, but time will tell.

[Davydd]

Do the math on what 32 battery cells would be to get to 1600ah. I doubt they would cut the floor and put access from above in to get to them. There is no reason to with lithium ion. Most likely they attach the boxes and then have more support holding them up.

They would need 32 of these for 1600ah. This is just my guess but it fits the video image.

http://www.electriccarinternational....-Batteries.php

200Ah, 3C, 3.2V
Model: BP-HZPP-200
LiFePO4 Lithium EV Battery
Cell Dimensions (L x W x H)
10.4 x 2.44 x 10.0in
264 x 62 x 255mm
$236 each

[Davydd]

Curiosity got to me. I have the high idle fixed package with Autogen (automatic engine start.) The new Roadtrek EcoTrek was announced this past week and I believe they call their auto start Voltrek. In reading the Q&A on Facebook it was stated Roadtrek did not use the high-idle package. The high idle fixed package came from Mercedes Benz as an option with an MSRP of $602. So, I wanted to see what that meant. The outside temperature was 81F. My battery cells at rest were 78F-80F.

First I started my cold engine with the key as you would normally do. The engine RPMs under normal idle was about 700 rpms. The charge rate on my Silverleaf screen hovered around 160 amps input.

Then I started my engine without the key in the ignition and high idle kicked in. the RPMs were around 1100. The charging hovered around 200 amps input.

When you drive at highway speeds and RPMs up around 2200 or higher you get a charge rate of about 220- 240 amps. That is about the highest on average I've noted. Charge rate varies with temperature and how charged the batteries are.

The obvious conclusion is the higher the RPMs the higher the charge rate meaning faster charge. I have a 270A Nations second alternator I believe designed for Sprinter application and further custom designed for Advanced RV. I have no idea what is in a Roadtrek EcoTrek so I can't claim any apple to apple comparisons. Both Advanced RV and Roadtrek have made claims of charging up to 300 amps. I am not sure under what parameters and conditions they can achieve that. I do know I can get simultaneous input from shore power, engine alternator and solar panels to achieve 300 amps parked.

The other big issue discussed frequently has been the effects of idling on the engine. There have been many caveats and some outright fear about it. Advanced RV governs their autostart to run for 1 hour and 45 minutes. Mercedes Benz says after a period of time 2-3 hours via various reports to drive on the road for 35-40 minutes. I assume it is good to have higher RPMs with those concerns. So, does 700 RPMs at normal idle vs 1100 RPMs at high idle make a significant difference for the engine idling issue other than faster charging and higher amps? I doubt anyone has any data to prove anything or they would not be so CYA general about it. The difference of 40 amps to me is not significant but I will take it if higher RPMs are good. Seemingly can't hurt.

Bottom line for me is with a totally electric B with no propane I can use almost all the electricity I could possibly use in a normal situation from my batteries in a days time I desire (except air conditioning) and recharge my batteries back to 100% in under an hour most times. Could I throw away my 30A shore power cord like Hammill threw out? The answer is yes to that as I went on the road from February 23 to about May 15 without plugging in. However, I think I will be prudent and hang onto it.

[booster]

It think the biggest thing with the high idle would be likelihood of someone complaining if it was idling in a campground or on the street. 1100 is usually a lot louder and more noticeable than 700rpm, and really more noticeable that n 545rpm that some of the gassers run (our Chevy 6.0 idles there).

[Exechobo]

I can see people complaining about the engine idling out of ignorance as much as real noise concerns. But I wonder what the emissions are for the engine vs a generator- both air and noise emissions. Of course any engine running is noisier than a 30 amp service!

It would be interesting to run a comparative test of decibels, even using a simple iOS or Android phone app.

[booster]

At least for gas, the van engine is going to be way quieter and less polluting than the generator. For diesel, it will be closer for most diesels, although some of the newer ones are pretty quiet.

On a long trip last fall, we were surprised how many campgrounds had put in no generator areas, and many also made them no engine idling. We stayed in the no gen areas, but would do our campground walk every day and it was amazing how noisy and stinky the generator areas were. The worst were the big diesel pickups running at fast idle and belching stink and noise, you could hear them blocks away. It was kind of like being at the midway of a county fair.

I don't think you would get a lot of complaints if you weren't in the no idle areas, especially if you were just doing a 5 minute microwave run. Idling for hours in a mostly tent area, could be an issue.

[markopolo]

On my van fast idle doesn't seem to make much difference in amp output. I have 624 RPM (approx), 1070 RPM, & 1360 RPM on a switch. I only have the single stock alternator and the PCM seems to automatically "make" the parts involved produce the required amps when running the microwave oven for example.

I think the purpose of fast idle or high idle is more for the diesel engine's benefit. 1100 RPM or so for extended idling seems to be a common recommendation on the diesel forums. The reasons often given are that it prevents carbon buildup, increases cylinder pressure & temperature for more complete fuel combustion, prevents wetstacking etc.

Google "1100 RPM for extended idle" or similar and you'll get lots of results.

In late 2012 I asked Sprinter Engineering Support about idling and received an email from them with the following info:

Per your request, with the SCR technology of our engines, we do not recommend idling a Sprinter for longer periods than 2.5 - 3 hours.
Even with the high idle engaged, you should not exceed the aforementioned times to avoid clogging the DPF or damages to the EGR valve.
Fyi, the fuel consumption is .4 - . 5gal. per hour of idling.

By specifically noting "Even with the high idle engaged" in their reply it could be interpreted to imply some benefit to engaging high idle.

[Davydd]

No doubt diesels idle louder than gas engines though the NC3V (2007+) Sprinters are much quieter than the older T1N Sprinters. Both idle RPMs are about equally loud to my ears so I don't consider that as a decision issue. 700 RPMs are not going to get anyone a pass. They are not nearly as loud as Onan generators or the large diesel pickup trucks, but whether posted or not in the campground rules, I think all vehicle engine idling, including gassers, should fall under generator quiet hour use rules. That is just common courtesy.

[booster]

Originally Posted by Davydd

but whether posted or not in the campground rules, I think all vehicle engine idling, including gassers, should fall under generator quiet hour use rules. That is just common courtesy.

I totally agree.

And in hindsight, I would also add that, rules or not, if you are in a tent type area that is very common for the no power sites, don't run a generator or the van. Of course the exception would be if all the tents have Hondas running, which seems to be getting very common.

[Davydd]

I downloaded an iPhone decibel meter app. I got the highest rated free one. I didn't check any reviews to its accuracy. But what I did was stand 10 feet directly in front of my B to check the decibels with the engine idling. The meter read:

High idle: 78 average

Normal idle: 76 average

I didn't think there was much difference and I was right I think in that regard in that I doubt I could have discerned the difference in a blind test of listening. Walking around the B, directly in front was very much the loudest. Anywhere else was 65 and lower. But as far as I am concerned, noise is noise at any decibel in a campground.

[wincrasher]

David that can't be right. If you recall, I measured my Onan at 77 decibels (in my shop over a concrete floor) and I thought that was appalling. I don't think that iPhone app is very accurate.

[Davydd]

wincrasher,

I mentioned that. I have no idea how good that iPhone app is but what I was trying to do was see if there was a significant difference between regular idle and the high idle option since the question came up and curiosity got to me. Maybe some time using the same app I could test an Onan generator but in the same location and conditions as the engine itself. Not that I really care. They're all loud.

[Fastpaddler1]

I have found that running my genset to charge my house battery in a Provincial Park depends on the regs. In some parks genset useage is restricted from 0900 to say, 1 PM. Running a genset to power a microwave would be unwise at midnight for example.
The use of an airconditioner during the day at a commercial RV resort can be annoying to neighbours too if the unit is loud. Mine is quieter outside but noisier inside.
Running the engine to charge batteries where no shore power is available is hardly practical given the time it takes unless/unless you have lithiums and the new technology,

[stanw909]

I think the DB level of Mercedes diesel engine could be the same as the Onan but the higher pitch of the Onan would be more annoying to the listener.