New Roadtrek RS E-Trek

[Mike]

Originally Posted by markopolo

The rapid charging part will generate a lot of excitement as it becomes more widely known and shown to perform as promoted.

I don't think anyone has figured out how RT is doing that.

Can it (the rapid charging) be accomplished with a regular 3500 watt generator or can it only be done with the under-the-hood generator?
Are they supplementing the 3500 watt under-the-hood generator with output from the Sprinter van's alternator?

Bottom line, if it it is eventually shown that it doesn't work, why did they make the claims in the first place? They had to know someone, somewhere, would ask how the basic mathematics of the recharging claims are possible, knowing how converter/chargers, and generators, and alternators all function, and how batteries absorb, and store, and discharge energy?
Did they think no one would ask, or notice?

[booster]

As was mentioned, it is the rapid charging that may have backed them in a corner. The way they worded the statements was technically true, but severely deceptive.

Claim one is that you can run the AC for 9 hours, with compressor on, off the batteries. Most likely true (we don't know the amp draw of the AC exactly), but it would take the batteries to essentially zero state of charge. This is destruction zone for batteries, but still the statement is true, there is that much power. Up for grabs is what happens to the AC when the voltage drops as the state of charge goes lower.

Claim two is that you can recharge your batteries in 40 minutes after running the AC for 9 hours. Again, this is technically true, as they don't say that you can FULLY recharge your batteries in 40 minutes. Any amount of recharge would make this statement technically true, but I would bet 98% of folks would read it as recharging to full in 40 minutes, and this is what I think is severely deceptive.

Claim three is that you can idle the Sprinter whenever you want, for as long as you want, to dry camp as long as you want. Not specifically stated in these terms, but definitely stated. Mercedes says otherwise, but no comment on why it is OK by Roadtrek. Still in limbo, but if you can't idle the Sprinter whenever you want, many of the e-trek claims and benefits go out the window.

Could a customer go after them for false advertising after they found out it didn't work as they thought? On claim one and two, probably not, as they are technically, but deceptively, true. Claim three might give some recourse. IMO, if you are claiming to be the tech and innovation leader, you should be prepared to explain and defend your claims, as they are new to your customers. Facts and calculations don't lie (can be manipulated though), and this is pretty basic science we are talking about here. Test data is unequivically the gold standard, so it sure would be nice to see some.

[markopolo]

It is a fascinating subject in more ways than one.

It looks like American RV sold another: http://www.americanrv.com/customer-feed ... xperience/

# 1 - none of us know for sure what generator is under the hood - after 7 months! - but we speculate on how well it will work etc. It brings out opinions like no other rig and people get really excited when they learn about it. At the very least it will work substantially as advertised. We probably get too caught up in specifics. Camper A might get 5 hrs A/C and Camper B might get 10 hours etc. etc. That's what happens now. Camper A dry camps for two days and runs out of water and Camper B - with the same rig - dry camps for 4 days and still has water. It all varies anyway.

# 2 - Other type RV owners are noticing it They may not have ever even considered a Class B but now they know the name Roadtrek and E-Trek. More people interested in Class B's is good

# 3 - I think that just about everyone agrees there's plenty to power the appliances. Maybe not all at once but that is typical of most Class B's.

# 4 - Booster's point - charged or charge it's in the definitions and your understanding of the terms. I can speculate how RT can get it to pump out maybe up to 400 amps by combining the generator the alternator and solar. And for the first while, the 8 batteries would just soak every bit of that up. The batteries would be charged enough to function and the solar and or driving would top them off. Note: This is all just guessing on my part.

A video showing a large amount of DC amps flowing into the batteries would be fun-to-watch proof.

It could have a mostly 24 volt system - they've installed a battery balancer which is normally used for that, a 12v/24v system - that would up the overall efficiency.

[Mike]

Probably true about the increased interest in the company and the product. Any publicity, good or bad, is good, as they say. The majority of potential customers may not understand or care whether the claims are based on real world usage, and can be relied upon as true and accurate and provable. If I were in the market for a new van, I would be interested only because of the price. When you're shelling out $100,000 plus for a converted van, it had better be able to live up to it's advertised capabilities. I'm pretty sure bigger companies than Roadtrek have been the targets of false advertising lawsuits for a lot less.
I guess we wait and see. I hope it doesn't turn out badly for them. More competition is ultimately better for the industry niche and the customers, as seen by the impressive gains made by Winnebago, once they got organized and put their minds to it.

[booster]

As said, a lot of good could come out of the e-trek adventure, if Roadtrek is able to figure out what does work well, and what folks really want in a class B.

Marco is right that there is not really much of question on most of the things the e-trek is claimed to be able to do. I would definitely agree that the AC and recharge time has turned into a big distraction from the rest of the things. Also in the equation is that the time you can run the AC on the batteries isn't as big a deal if you really can idle the Sprinter for long periods, as then you are pretty much right back to where you are with an Onan. If Roadtrek got an OK to idle from MB, I think most of the other questions would fade away as borderline irrelevant. A plus side that Roadtrek doesn't talk about is that your batteries will get charged quickly when driving, assuming the engine generator can be used when driving (eat too much hp or mess up the engine ECU programming for load?). This could be a much bigger plus than the AC thing, as I think a lot of B folks camp off grid for a number of days, or weeks, then move a ways. The e-trek would recover way more AH in a couple hour drive than any other B, most likely. The recovery probably would be needed if you used the e-trek as it can be used (and most would), as the 245 watt solar almost certainly wouldn't be able to recover the batteries completely if you were using the microwave, induction stove, compressor frig, surround sound and tv, plus your other stuff, without the extreme conserving we all do. I do admit it would be nice to be able to use power like you were on shore power when you are not. We have almost 1/2 the battery capacity of the e-trek at 375 AH and about 80% of the solar at 200 watts, so it will be interesting to see how long we are able to really go without shore power or driving, when we get out for extended times. I think that will give me a much better idea how an e-trek will perform. We don't, however, have enough inverter or wiring to run the microwave on DC.

I think a lot of the folks that would be interested in the e-trek because of its off grid capacity, are also the "real" campers in the group of people the buy a class b (not soccer moms and weekenders), and I have read a lot of comments that the e-trek layout was not the favorite of those type of buyers. Putting the e-trek capabilities in the CS, I think, has more closely matched the entire product to a specific group of buyers, that IMO, have been being ignored lately. The more storage, big frig, microwave up higher, two seat (with armoire) CS floor plan, with the e-trek capabilities, could turn out to be the choice for folks that like to be off grid without having to unduly save power all the time. The AC would not be an issue for most of that group, as they tend to be in places that have pleasant weather, and follow that weather around. Of course our problem with going that way would be coming up with the $140K

[gerrym51]

You can run a diesel engine hour after hour. it will not hurt the engine-BUT it will quickly clog the DPF filter and EGR valves. that will render the system useless.

[markopolo]

I checked the RV.net comments http://www.rv.net/forum/index.cfm/fusea ... page/2.cfm and saw the mention of how the surface charge can lead you to believe the batteries are charged when really they are not. Any load would quickly cause the capacity to be inline with real state of charge which would be much less than fully charged.

I agree with one of the comments over there that measuring voltage isn't the best way to measure state of charge. But, how else can you measure with AGM's (practically speaking)? You can't test the specific gravity.

This chart http://marine-electronics.net/techartic ... /b_faq.htm is interesting.



I believe the original source is Deltran.

It shows that at approximately 1/2 an hour the batteries will reach at least 12.7 volts from a discharge state. However several hours of charging are still needed to actually fully charge the batteries. A typical battery monitor would display the charged or charging light at 12.7 volts leading most to think the batteries are charged.

The first thing you'll notice about the chart is that they are charging a 50ah battery bank with a 20 amp charger. Multiply both those numbers by 16 and you get an 800ah battery bank and a charging amperage of 320 amps. It think those numbers parallel nicely with the guesses we've made about the E-Trek's battery capacity and possible initial charging amperage. In the chart you see over 14 volts at around the 2 hour mark. That is significant because it still fits into the idling guidelines Mercedes sent to me:

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 damage to the EGR valve.

Fyi, the fuel consumption is .4 - . 5gal. per hour of idling.

At 2 hours the batteries still aren't fully charged but they are substantially charged. Maybe at 90% capacity even if a load is applied to them.
According to the chart, the amps absorbed by the battery bank is down to just a few amps after being on the charger for 5 hours.

I could be completely misinterpreting the chart and please explain it if I am.

[markopolo]

I found a few under the hood mounted generator options. One of these might be what is used in the Etrek

Mobile Electric Power Solution, Inc. (MEPS) - http://www.meps.com/products.html



Aura Systems Inc - http://www.aurasystems.com/pages/prod_intro.html



Raven Technology - http://raventechpower.com/



Fabco Power - http://www.fabcopower.com/generat/bgen.htm



The current clue from Roadtrek re: the RS E-trek is:

Generator - The 3.0 Litre Mercedes diesel engine, at idle, is used as the power plant that feeds 3.5 KW of power to the electrical system, running everything when driving or parked. When driving, it is even more powerful, and charges at 5.5 KW.

Previously I had limited my internet searches to 3500 watt units but the latest info shows the under the hood unit can output 5500 watts at higher engine RPMs.

[markopolo]

Any ideas what this black box in the RS Etrek is for?



I wonder if it is the control unit from Mobile Electric Power Solution, Inc. (MEPS)?



The MEPS control unit can be side mounted as shown here:



Also I noticed this comment by Jim from Roadtrek on FB.



The E-trek has 960 Amp hours of battery storage.

The specifications page on Roadtrek's site still shows 1600 amps hours for the RS E-trek:



I don't know if the "E-trek has 960 Amp hours of battery storage" comment from Jim is an error, or a correction or new specification for the E-trek.

Interesting stuff anyway.

[booster]

I really like the specifications page, where the e-trek is rated at 6 volts and the others at 12 volts. Noooobody would ever get confused by that, would they, since they both say total amp hours and don't list the voltage? Hammill must have made some sort of error, unless they have started putting higher AH batteries into the e-trek. 960AH divided between 8 six volt batteries comes out to 240 AH per battery, which is a available in GC2 (?) batteries, but maybe only in wet cells. Trojan makes 220, 240, and 260 AH versions in wet cells.

[markopolo]

The mention of EarthRoamer sent me exploring

Looks like they also skip the installation of a separate generator: http://www.earthroamer.com/xv-lt/system ... generator/

No Noisy Generator
...........................................We order Ford F-550 turbocharged diesel Power Stroke trucks with the dual alternator option which provides a quiet, fuel efficient, factory installed 3.7 kWh generator. We install an advanced battery isolation system and connect the factory alternators using low resistance, #4/0 tinned copper marine cable to the massive absorbed glass mat (AGM)camper battery bank. Whenever driving or the engine is idling, the AGM battery bank is being charged by the high output dual engine alternators. At idle, the Power Stroke diesel burns approximately .5 gallons of diesel per hour which is significanly less than many RV generators at full load.

The new Power Stroke is incredible quiet – this is from a Car and Driver review:

…the diesel is remarkably quiet. Hardly any clatter or turbo noise is audible, and the interior
is actually quieter than in the last Lexus we tested. At wide-open acceleration the Ford
measures 69 decibels (emphasis added), five fewer than a Lexus ES350; and even cruising
at 70 mph, the F-250 is a hushed 66 dBA compared with the ES350’s 69.

I have to bring out my dB meter and test my older - and noisier - diesel van. New diesels are much quieter. Clatter or "clackity clack" would describe mine .

[casd]

Yamaha use to make a 3 cylinder diesel , (Water Cooled) was about 3k then I was selling them at the time in the 80's , I delivered one to a retired american Execucutive that moved to the Adirondacks to live of the grid

[markopolo]

A single cylinder diesel generator like the 3000 watt PowerTech PTRV-3 is adequate. Some Sprinter owners order it with custom van builds from Sportsmobile. The complaint I've read about is that it reduces ground clearance to only 6 1/2 inches so you could damage it.

It is larger in every dimension and almost twice as heavy as the Onan 2500

PowerTech PTRV-3 Diesel (3000 watts):
Length: 28"
Height: 15"
Width: 23"
Weight: 260 lbs

Onan 2500 Propane (2500 watts):
Length: 22"
Height: 12.8"
Width: 16.3"
Weight: 125 lbs

The PowerTech single cylinder PTRV-3 Diesel is closer to the Onan 3600 generator in size:

Onan 3600 Propane (3600 watts):
Length: 30"
Height: 14.4"
Width: 19.7"
Weight: 178 lbs

As far as I know, Advanced RV is the only Class B RV builder that has the option of choosing the Onan 3600 Propane powered generator.

This post: http://www.classbforum.com/phpBB2/vi...art=108#p15035 by pattonsr shows that using newer technology full featured inverter/chargers could allow you use a 2500 watt generator and not loose the capability of say microwaving popcorn while the A/C is running. You'd need a sufficiently sized battery bank though.

[pattonsr]

I think the Great West Legend EX also uses the Onan 3600 generator. As I understand the extended Sprinters can be fitted with the larger Onan.

The problem with generators on Class B Sprinters is that they are not in a sound proofed compartment like most other larger RVs. If the Onan 3200 QD was in a sound proofed compartment, it would be perfect. It puts out a very stable sine wave. The reality is that 2014 Sprinters are lower to the ground and no one wants to lose space in the rear to house a generator. Thus everyone wants to find a way to eliminate the noisy underneath generator.

Airstream trailers are a heat magnet due to the shiny aluminum. Lots of owners use a propane converted Yamaha 2000is from USCarb to meet their needs without A/C. If they will need A/C on a trip, they bring along a second 2000is and parallel them to have a full 30 amps. As I mentioned previously, time will tell if a single 2000is will run a 15K A/C (with a SmartStart) aided by a boosting inverter.

I have faith in Magnum since the engineers came from Trace and Trace produced a classic boosting inverter (not pure sine though). The proof in the pudding will be how fast the extra boost is delivered. In other words, will other electronic devices still run even when the small generator is maxed out and the boost is applied. If there is a voltage sag some devices will reboot.

[markopolo]

Anyone remember this photo of the batteries in the E-trek at Lake Region RV's?



I came across photos of another E-trek (newer I think) and they really have tidied up the battery compartment. Looks like less wire used also.



It is easy to see six batteries in the rear now. It will be easier to replace them all when the time comes for that also.

[Mike]

Would be even easier if they used a bus bar to connect them. It's supposed to be a better method for battery charge rate and voltage distribution, than terminal to terminal connections. I read an interesting article a while back (may have posted a link on here to it?) and it showed the author's home setup for his renewable energy system.

[markopolo]

Two posts on the Sprinter Source Forum ( http://sprinter-source.com/forum/index.php ) are very interesting:

# 1 http://www.sprinter-source.com/forum/sh ... stcount=27

My E-Trek uses two types of DC voltage, 12 Volt and 24 Volt. The system consists of:
One 12 volt Lithionics Battery in the engine compartment
Two 24 Volt 200AH Lithium batteries in the rear
24 Volt 140 AMP Nations Alternator
AIMS 6000 watt inverter
Tripp Lite Inverter Charger
50 AMP Lithium Battery Charger
ProVista MPPT Solar Controller
Lithionics Never Die Battery Manager

The 24 volt 140 amp alternator charges the rear battery bank only
The Aims unit is connected to the rear 24 volt battery bank and is used strictly as an inverter. It powers all the appliances that normally operate off shore power
The solar panel and 24 volt lithium battery charger are connected to the rear battery bank only
The chassis alternator charges the 12 volt lithium battery installed in the engine compartment
The 12 volt system operates DC powered appliances and the lighting in the motor home portion of the unit
Shore power is routed to the 12 volt battery charger and the 24 volt battery charger

Tripp Lite Inverter Charger? ..........

and # 2 http://www.sprinter-source.com/forum/sh ... stcount=28

Just ran into a fellow with an Etrek at a camp. He's had it for 3 months and said two things; One, you can't ever "know" for sure / very well what charge you have. There is a readout in the back under the sofa that can only be read by opening the back door. Not very useful. And two, "Cut everything advertised by close to half... maybe you get 60% of what they say." And it takes twice as long to charge and never seems to fully charge unless plugged in."

All very interesting. Head on over to Sprinter Source Forum to read more: http://sprinter-source.com/forum/index.php

[markopolo]

Originally Posted by pattonsr 19 Jul 2013

I now believe the E-Trek is using a Nations 280 amp unit ............

You called it right 140 amp at 24 volts would be 280 amps at 12 volts.

[mlts22]

One of the first things I would be doing with a new "B" would be installing a voltmeter with a switch (so it won't be yet another annoying glow when trying to sleep) and an inline fuse.

Of course, an ammeter can't hurt either. I just grumble at trying to guess how charged the battery is.

[booster]

"Just ran into a fellow with an Etrek at a camp. He's had it for 3 months and said two things; One, you can't ever "know" for sure / very well what charge you have. There is a readout in the back under the sofa that can only be read by opening the back door. Not very useful. And two, "Cut everything advertised by close to half... maybe you get 60% of what they say." And it takes twice as long to charge and never seems to fully charge unless plugged in."

We have been waiting a long time to get some feedback from actual owners of e-treks to see how close they actually perform to the claims. If this guy is typical of others, it looks like the capabilities have been quite a bit overstated, as many folks speculated. I will be looking forward to hearing from others as there are more e-treks getting out in the real world.