PDA

View Full Version : Electric Coach Conversions - Thoughts?



CLRH2O
07-06-2018, 01:31 PM
Hi Everyone!

Cheney here (other half of Escape Velocity) and I have a question as to why we haven't seen anyone converting their coaches to all electric?
I've spoken to Newell, EV West, and TransPower, but no one seems to really be jumping on this band wagon for the consumer market. TransPower was the closest with their line of school buses now being utilized in CA, but nothing for the individual RV market. I also looked up Allison Transmission and they seemed the most receptive with their current projects to be developing heavy, long range electric vehicles, but the trickle down into the consumer market doesn't appear to be happening anytime soon. And yes I've seen the Winnebago in-town RV that's electric which I was very excited about since it's a start.

With that being said, who would convert to electric if they could? Clearwater and I are very conscious of our carbon footprint and have even been asked if we're being hypocritical by going out and buying a old diesel pusher. We like to think that even though we're still using diesel, due to our minimization, our overall footprint will be smaller, but it does eat away at me to be using up limited resources at such an inefficient rate.

Do you, or do you know anyone that has tried to convert their coach to at least a hybrid, replacing the engine with an electric motor and keeping the generator as a backup combined with a solar array? My wishes would be complete, if we could only get rid of the diesel lol Does anyone else feel this way too?

Let's Discuss!
-Cheney

Gil_J
07-06-2018, 04:33 PM
Baby steps. Our coaches are all electric when parked. That's a change over past years. If course, it's only a migration from propane to electric which isn't really what you're driving at.

Although the day may come, I struggle with seeing an all battery or even hybrid power being economical for the few miles most RV conversions are driven on annual basis. If CNG availability becomes widespread I suppose I could one day see our coaches becoming CNG/battery hybrid powered using the battery/CNG for house requirements as well.

Although this would be good with respect to carbon footprint, all would not be positive until we can fully migrate away from lead plated batteries.

We still need 500HP to move these big coaches, so an electric motor of this size, enough batteries to serve the power storage needs, and enough generator power may be substantial.

Never is a long way off, so I won't suggest this will never happen. My guess it could be 10+ years away unless hydrogen power or yet to be tapped energy option comes to market. Of course there's always the Tesla and tend option ;-)

TheGadgetGuru
07-06-2018, 08:09 PM
I'm going to be a bit more optimistic than Gil and will predict that we'll see electric motor-operated motorhomes within the next three to five years. Why, you may ask? A rising tide raises all ships and with Tesla, Mercedes, Freightliner and others sinking big bucks into the development of electrically powered semis, having this technology "trickle" down to a motorhome chassis may be a logical step.

I'll add with Greyhound being an important customer to Prevost, having electric powered busses surely are being discussed.

Personally, since I have limited (if any) mechanical skills, I'll be interested in a motorhome that bypasses the confusing diesel engine with a simple electric motor.

Since there's folks who are a lot smarter than I am on this site, I'll ask that when connected to 50 amp power, in theory, how long would it take to recharge a battery operated motorhome?

BadFitter
07-07-2018, 09:33 AM
Looking at the published charging info for Tesla, maybe some sense of electrical requirements can be made. Needless to say, recharging a Model S is light years easier that recharging a 50,000 pound electric vehicle like a truck or RV would be.

Tesla says using a 50 amp, 240 volt connection, it takes one hour of charging to obtain 29 miles of range. If you want to drive say, 200 miles the next day, one would need around 7 hours of charging. Again, this is for the Model S car, not a big truck or RV.

Another consideration is that you will be using ALL of the capacity of the 50 amp, 240 volt campground connection. Assuming you would like to cook a meal or run the air conditioners, you would need to share the connection. If it is hot outside, you may need all of the power capacity just to keep the bus cool and run the normal things you use inside the bus.

Tesla (https://www.tesla.com/support/home-charging-installation#wall-connector)

BoaterAl
07-08-2018, 12:19 PM
I'am no electrical engineering college student. Keeping in mind all the posts we read about electrical vehicles where does one find the correct path ?.
Plug in and charge ...go 29 miles after sitting for 1 hour to accomplish this distance. Standing outside in a rain storm holding onto a 240 volt connection, what could possibly go wrong ?

I'am not posting to say the sky is falling on this electric car, bus, truck subject at all. I'am just a little stand back approach looking for better info on the whole industry for the time being.

AL

TheGadgetGuru
07-08-2018, 07:35 PM
I have no doubt that negotiations are underway to add high speed chargers at various truck stop parking lots around the country. Within five years you may not hear the sound of generators buzzing away while the drivers grab some shut eye. Add to that vision some autonomous features and this industry could be undergoing a revolution.

Donnie Myers
07-10-2018, 06:18 AM
I will jump in and say I won't see this in the Prevost conversion market in my lifetime! If you are concerned about "carbon footprints", just think about what they will be with the power plants required to produce the amount of power needed and the infrastructure it would take. Fossil fuels will be around for a long time. There is no such thing as free power.

Also, think about braking. Sure you can reverse polarity on the motors, but even trains have brakes on the wheels. All electric trains use magnets in the ground. The cost of the all electric full size 50k plus pound motorhome would be off the chart!

Pete
07-10-2018, 09:21 AM
I agree with Donnie, there would also have to be massive weight reductions on the coaches as well. I also think the closest conversion now available would be CNG which is now being used by tons of local city buses. I have no idea for the cost of converting a bus, even if it could be done.

TheGadgetGuru
07-10-2018, 04:04 PM
This makes for interesting reading - Mercedes Benz Electric Bus: https://electrek.co/2018/07/10/mercedes%E2%80%91benz-new-all-electric-ecitaro-bus/

CLRH2O
07-11-2018, 12:50 AM
Clearwater here, adding a few random things we've run across on the topic that made the idea really stick:
----

Cummins, who've been working in the space with R&D for about 10 years at this point just made some major moves, including:
https://www.cummins.com/news/releases/2018/07/02/cummins-announces-acquisition-electric-and-hybrid-powertrain-provider

And previously from Cummins:
https://www.equipmentworld.com/cummins-developing-fully-electric-powertrain-we-are-not-just-a-diesel-company/

Allison Transmission is sending out info about using their units with electric drive-trains, and has been putting a decent amount of R&D into the space:
http://www.allisontransmission.com/company/news-article/!details/2017/07/14/terberg-electric-truck-uses-allison-transmission-to-maximize-productivity-launch-with-gcw-up-to-65-tons

Volvo is investing deeply as well:
https://cleantechnica.com/2018/05/16/volvo-blasts-into-electric-trucks-with-new-garbage-delivery-trucks/

TransPower is currently operating in the states, and they've provided a decent amount of info via the detailed PDFs.
http://www.transpowerusa.com // https://www.youtube.com/watch?v=XJ2C4_7bqrk

And China of course has more companies (incl. major player BYD) building / operating electric buses than anyone anywhere else in the world:
https://www.citylab.com/transportation/2018/05/how-china-charged-into-the-electric-bus-revolution/559571
--
https://electrek.co/2016/11/10/all-electric-garbage-trucks-are-coming-byd-unveils-a-3-9-ton-truck-with-100-miles-of-electric-range/


With a bit of casual banter between us, some humorously uneducated speculation and a bit of armchair research; we imagined a custom fabricator will be needed for the new *motor mounts* and that the use of 4 inline (2x2) WARp motors mated to a 2 speed trans along with maybe 500kWh of high discharge cells in a battery bank should be a decent start to getting a 45k to 50k lbs of bus up to speed and down the road.

We entertained a setup consisting of 2x of the following for turning the drive axle which would give 2000lbs of torque at a cost of around $16k for the *base* hardware (not batteries, not controllers, not wiring - just the power plant(s) and the transmission:
http://www.evwest.com/catalog/product_info.php?cPath=8&products_id=213

Cool video on mating the above DC motors in series and to the transmission:
https://www.youtube.com/watch?v=Ie7qvo-aC5k

For comparison, a Rebuilt 8V92TA (not to speak of a Series 60 or Volvo D13) costs around $25k on it's own. Add in the Trans and you're up to $40k for used/rebuilt power-plant parts alone. Donnie, I think you're likely more knowledgeable on these topics than most anyone else in the country. Do those prices for a diesel power-plant (rebuilt) sound roughly accurate?


As for the "fuel", LifePo4 prismatic cells are still the most readily available you can find in bulk without going utterly broke - but these don't seem to have the discharge rate (only something like C1 discharge at best) needed for the task in our estimation. and higher energy density high discharge cells like previously mentioned don't come dirt cheap juuuust yet. About those high discharge high energy density cells; Maybe 2170 cells with a Lithium-nickel-cobalt-aluminum chemistry like what Panasonic is currently pumping out en-mass at the moment would be a good fit?

Donnie brings up - in our honest opinion - pretty much the most important part of this entire conversation. And that is where do you get all that "energy" from in the first place. Obviously displacing the liquid fuel used by OTR heavy equipment and cars saves on tail pipe emissions. But then it's just shifted over into power plant emissions. So as to the 'green fields and butterflies' aspect of things - major MAJOR inroads in solar, wind, thermal and tidal energy generation still need to be made.

There is, as is obvious, a LONG way to go. But 'long' these days is measured in years, not decades. And that's a nice reality to acknowledge.

P.S. - it's late, I haven't checked for grammatical errors and I'm bleary eyed so please forgive any of that stuff in this post :)

Gil_J
07-11-2018, 07:19 AM
Clearwater, great references.

For urban truck travel it looks like battery power is here now in some parts of the world. 3,000 pounds of batteries for a 150 mile range looks like a limiter to long haul solutions...at least for now. The equivalent of 50 Tesla battery packs for urban applications must also pose a space and cost concern.

You're not far off with a Detroit series 60 and transmission being in the $40K+ range. In fairness, the long term cost must also be factored. Electric motors win on long term service costs, although I wonder what their life expectancy is. The cost per mile over the life of the batteries would be interesting. Your references had a comparison chart, but it wasn't clear if that was just fuel versus charging costs or it included the cost of the batteries. All just numbers, but numbers limit customer acceptance.

Thanks for sharing.

CLRH2O
07-11-2018, 10:43 AM
Of course Gil, Sharing is what forums are all about


I was thinking about the weight's of all this stuff as, at the end of the day, what you need to push you down the road (and stop you moving) is directly proportional to that number.

Most Prevost's seem to have 250 gallon diesel tanks right? A gallon of diesel weighs 6.943lbs (lets round that up to 7 pounds and ignore the weight of the gas tank it's self for this fuzzy maths calculation). So a tank of go juice weights you down 1750lbs. And that falls over the trip as fuel is burned.

The engine it's self, a Series 60 is about 2800lbs, and an 8V92 is 3200lbs. So we're looking at an average of 3000 between the two most common power-plants in Prevosts (I'm not counting the D13, but I think it's in the same range).

With the fuel and engine it's around 4950lbs, lets just say 5000lbs. And then you've got the Allison Trans weight dry/wet... Average it at another 1000lbs on top:
----
Or around 6000lbs for a traditional diesel power plant and it's go juice.


If the battery bank mentioned in the PDF weighs in 3000lbs, This leaves 3000lbs for DC motor weights and gearing. But DC motors don't weight anywhere near that range and are much much much lighter. Just for examples sake, and because so much of this data is readily available; I want to say the dead in the middle of the range single motor P-series 85kWh Model S's drive-train - which includes the single DC motor, electrical converter, control module(s) and the drive-line differential gearing box all together - weighs in at 150lbs. And that really tiny power plant nets you 443 lb⋅ft / 601 N⋅m of torque & 470 hp / 350 kW of HP. I think two of those in series would be better for a bus, or around 880 lb⋅ft / 1200 N⋅m of torque & 940 hp / 700 kW of HP in exchange for 300lbs of weight. That seems pretty decent as a start right?


https://www.quora.com/What-percentage-of-the-Tesla-Model-S-weight-belongs-to-its-battery-What-about-in-terms-of-volume

https://en.wikipedia.org/wiki/Tesla_Model_S#Specifications


Andy Gadget Guru: Thank you for adding in the links and info / ideas you did. I think you might be onto something with the idea that soon "this industry could be undergoing a revolution".


And on a more personal level - the BIG THING that keeps one of my own (Clearwater) eyes on this topic is the following: I look to this type of conversion as a means to reduce mechanical complexity, reduce running costs and reduce service costs for big rig ownership and operation. THAT, is the big deal for me personally

Donnie Myers
07-12-2018, 06:25 AM
Just so we are clear, I totally expect this to be the "norm" of the future. Moving people and freight from point a to point b is a different animal than a motor home conversion. If a person has to pay full retail, the Detroit prices aren't too far off for an RV owner.

As to the projected costs and reliability, I have my reservations on the electronics involved to control the charging and temperatures of the battery banks. We have already experienced some of this on a much smaller scale. The training of technicians and the price of the equipment the shops will need is mind boggling. I'm glad I'm aging out of the service business...lol You think its hard now to find a campground to get reliable 50a service for overnight parking just imagine the infrastructure needed for the future.

Almost every PLC controller or module ages out from 1-5 years costing a lot of time and money to retro. You may reduce some mechanical complexity, I don't think so, but the added technical complexity will take some time to adapt to for a shop in the Smoky Mountains or The Black Hills. A piston in a Detroit hasn't changed much over the years.

As a side note, most folks who know me, know that I really love technology..lol

CLRH2O
07-12-2018, 11:23 AM
All very valid points Donny.

I'm interested in hearing more about your experiences with the PLC / module(s) aging out and retrofitting thus far. There's bound to be a lot worth hearing there.

Battery temps are real concern, just as much as engine coolant temps are, that is for sure! You end up with a hefty engine rebuild bill when you get too hot right now. In the near future you melt part of a compartmentalized battery bank down and end up with a hefty rebuild bill just the same. Cooling when dealing with energy will always (and should always) be a concern to handle appropriately.

We can foresee a nice perk with cooling systems for battery banks being that the coolant it's self doesn't age out of service as quickly as SCA type 2-stroke coolant, and even 4-stroke coolant today does. Currently our coolants age out incredibly fast due to breakdown and contamination. I mean, the general methodology is a 'drain and fill' annually which is coo-coo when you really think about it. But the operating environment inside a diesel engine is a harsh place, and this it's the reality of things right now. Overall, battery bank interleaved closed loop systems will inherently operate more-or-less trouble free for longer, and that will be a plus. This doesn't mean without any issues at all - that's folly to think. But just that the coolant it's self not needing to be switched out for the life of the bank is an advantage over the annual drain and fill system we currently work within for the buses right? One less fluid to change has to be a good thing. It's certainly one less thing the owner will invariably forget about and F-up lol

And don't even get me started on the cheapo "B.attery M.anagement S.ystem" units that flood the low-end and mid-range market. Honestly, if it's not Victron or another well engineered system (there are a number that are worthy) I'm HIGHLY suspect of it's mere existence... let alone the thought of letting one physically touch your cells.


And you're aging out - nooooooooo ;D We need your knowledge around as long as possible brother! I jest, a good vacation from a life of hard work is always deserved!

Before you go, mind hooking your brain up to this here computer for a download? ;D

Garynmike
07-26-2018, 06:51 AM
Wow! Lots of terrific info and insight into the future of coaches... I have been wondering about this for some time myself and would love to pull out the diesel and stick in electric motors! I drive a 2017 Chevy BOLT and let me tell you it is FAST, quiet, easy to charge and the maintenance.... forget about it in comparison to an ICE vehicle!

Garynmike
07-26-2018, 07:24 AM
As you seem to be quite knowledgeable in this area would you have a few moments to help me decide what brand of inverter and converter I should purchase? I’m looking at having about 4 to 6 batteries in my “bank” eventually so I’d like to purchase something that will allow future expansion. Also, I’m looking at the NoCo Gen3 charger for maintenance... is that a good choice?

Gil_J
07-26-2018, 07:57 AM
Michael,

Victron, Magnum, Outback and Schneider are all common names in the mobile inverter market.

Before your question can be answered you'll need to identify your load requirements, alternator capacity, and if you have a future desire to use solar.

You certainly don't want to but a charger and an inverter. A unit with both functions is the only way to go.

Joe Camper
07-26-2018, 08:00 AM
If u get an inverter u need no converter.

Outback and Magnum r 2 good ones. Weather or not u r planning to get the OTR AC going or not dictates how converters choose a 12 or 24 volt.

CLRH2O
07-26-2018, 02:09 PM
I know a few things about one thing, and very little about another. That's why we're all here right? We each share that little thing we know a lot about and learn the rest from each other :)

This is veering a little bit from the exact topic of an Electric Bus Drivetrain conversion. And I suggest the start of a new thread if it needs to get any deeper as a conversation. But for now, converting your house side power needs is (at least it's how we look at it) a good way to both educate yourself on the process of electrification (any electrical system replacement would do this really) in preparation for something larger like an electric motor driven Bus conversion.... It's just a matter of time before one of us takes the leap and makes this happen. It's coming!

And so, on this off-shoot topic of inverter/charger I can only give a suggestion - for Victron. But it's neither inexpensive or without the need for being a bit techy. That said, a TON of people have chosen Victron for their setups for good reason and with great result.

Other's have used Magnum and Outback and been happy as well. But I've settled on Victron (and the Color Control GX control interface), so that's what I'm offering here as the suggestion. Someone else will offer something else. Go out, research and pick what you like :)

Do pretty much any blanket 'LiFePo4 Victron" youtube search and you'll end up with builds from Technomadia, RV Exodus, RV Chief, VeganRV, and sooo many others.

There is a WEALTH of information from the *early days* of 2013 or so from Technomadia which can lay a really solid basis of understanding that I HIGHLY suggest you digest. It did me a LOT of good getting my head around a number of topics. With which I then ventured outward to RV Chief and other's builds with a greater understanding of things.

Technomadia (the Pioneers you could say. Chris and Cheri are wonderful and have added SO MUCH to the Bus / Full Timing, and now Boating community)
https://www.youtube.com/watch?v=EHSpJWgeiEw&list=PLgtEZDX9EG7pA6lfj7PEPBMSymlemsaLE&index=1
and
http://www.technomadia.com/solar

RV Chief (note about the Chief's setup - he went FULL OVERBOARD on the battery tip - and I commend him... but we're personally not using 'Victron' branded cells due to cost)
https://www.youtube.com/watch?v=0gGBNRoJFDY

RV Exodus - (Great DIY Victron setup to check out)
https://www.youtube.com/watch?v=hj3L2Kxzuac

Journey with Jono (some good software setup for pairing Victron with Lithium banks)
https://www.youtube.com/watch?v=GrPQ5z-hWbw

VeganRV (a sort of top to bottom setup from someone who learned as they went)
https://www.youtube.com/playlist?list=PLS_ClYIy7cP67mBI633qcXZRmy68QGfkf


Hope you find all these (likely hundreds of) hours of info fun and useful!

Garynmike
07-27-2018, 06:50 AM
Joe, I would like to get the OTR A/C system working as it just seems logical that with everything in place to simply recharge the system and find the leaks. But we all know how that can go....

So how does that affect my choice of inverter? I know the starter batteries, which I have two, are connected together in parallel so that the output is 24v. Whereas the coach batteries I want to have in series so that the output remains at 12v but the amp hours are increased by the quantity of batteries. Right?!

I have heard of coaches having a switch that connects the two battery banks together in case the starter batteries are too low to turn over the engine... but that is a momentary thing and I have no idea how that needs to be set up since we are dealing with systems that are not the same voltage.

And yes, I certainly DO want to add solar panels to my coach in the future! So I need to take that in to consideration as well.

I’ll just say my head hurts....:confused:

Garynmike
07-27-2018, 06:52 AM
CLRH2O... what is your name/username/screentag/secret agent code? I really like to address people by something I can pronounce and can say rapidly more than once after being given terrific ideas and money/life saving info!

And by the way... THANK YOU for taking the time to put that info online for me and everyone else who will be searching for it in the next year. I know this topic has been gone over and over and over again but everyone knows that the hardware technology and suppliers keeps changing and what existed or was the right way to go 4 or more years ago is long outdated and probably not available.

So, again thanks to everyone who replied! That’s why I love this forum.... and that’s why I was willing to buy a 1981 coach and make the necessary improvements and repairs.

Garynmike
07-27-2018, 07:01 AM
Gil, thanks! I have had some prior experience with Magnum in my ‘95 Airstream Classic 36 but that was back in 2010. I see a similar unit is available but I think I might go for that Victron.... the double leg capability seems like what might be necessary to deal with the starter batteries (12v in parallel = 24v) and the coach batteries (12v in series = 12v) is worth the extra cash. Am I understanding that right? Will it charge both sides separately?

Hmmmm.

Gil_J
07-27-2018, 07:17 AM
Michael,

The inverter/charger would be for the house bank. In your case, 12V. The chassis batteries could be charged, really just maintained, with a low amperage inexpensive charger.

I agree that Victron makes a great product.

CLRH2O
08-02-2018, 09:25 PM
Garynmike - my pleasure man!

I have the same feeling you do about forums - this is THE place to really get the info down for future reference and adding as much as we can is the best way to do that :)

As for my name and handle. My actual name is Clearwater, and so my 'handle' is CLRH2O as an embellished abbreviation :)

CLRH2O
01-31-2019, 08:36 PM
More developments in the electric bus / coach / truck space:
-------
Tech: https://www.youtube.com/watch?v=REFobUaBl2A

Use: https://www.youtube.com/watch?v=ENRi7HiPNfg

These are some of the BIG GUYS in the space utilizing Siemens power systems motors and in house developed control systems (and bunch more stuff that you can learn about by researching them)

Bonus: some extra Siemens "SIMOTICS" motors info: https://new.siemens.com/global/en/products/drives/electric-motors.html

CLRH2O
01-31-2019, 08:38 PM
Follow ups:
---
Write Power (former Tesla Motors partner company)
https://www.youtube.com/watch?v=qHrrmkv1oaE


TransPower Tour 2018 - End User EV Truck & Bus Conversion Company
https://www.youtube.com/watch?v=R5eGPYnfWao

CLRH2O
01-31-2019, 08:47 PM
Fully Electric Double Decker Tag Axle Bus - North American Units - 'Green Power Bus':
---
https://www.youtube.com/watch?v=JY42HnpABaM
and
https://www.youtube.com/watch?v=uPqppzgWJo4
and
https://www.youtube.com/watch?v=DFXBfArMksc

And a delivered unit company driver walk-through:
---
https://www.youtube.com/watch?v=nquS25YmIVk


TONS more info on the types of buses they sell:
---
https://www.greenpowerbus.com/product-line/#heavyduty

CLRH2O
01-31-2019, 09:24 PM
MCI goes electric:
---
https://www.prnewswire.com/news-releases/north-americas--1-motor-coach-on-the-road-with-battery-electric-300646648.html

Vanhool goes electric:
---
https://www.vanhool.be/en/news/van-hool-builds-first-100-electric-coach-for-the-american-market

CLRH2O
01-31-2019, 09:30 PM
Finally, this is happening. The days of Twenty Five THOUSAND dollar diesel engine rebuilds waaaay too early in their promised lifespans... oil changes, coolant flushes, filters GALORE and all of the other consumables that need endless attention and cost are nearing an end. And honestly, it cant come soon enough. The thing that makes me smile is in 20 years people will be buying used Electric Coaches like they're buying XL40's today. YAY!

And BYD's been at it for over a decade:
----
http://en.byd.com/usa/bus/c6-electric-motor-coach

>> BYD is the world’s largest manufacturer of electric vehicles and batteries, and the global leader in battery-electric buses with more than 35,000 buses in service across 200 cities, 50 countries and six continents. The firm has delivered 280 buses in North America; and sold in excess of 650 buses in total to more than 50 municipal, transit agency, university, airport, federal and other commercial and private sector clients in 14 states, and across 4 provinces in Canada.

CLRH2O
01-31-2019, 09:31 PM
Let's go the distance (in miles)
---
https://www.proterra.com/technology/battery/