Electric Coach Conversions - Thoughts?

[Gil_J]

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]

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-percentag...erms-of-volume

https://en.wikipedia.org/wiki/Tesla_...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]

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]

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]

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]

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]

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]

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]

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=EHSp...emsaLE&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?lis...qcXZRmy68QGfkf


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

[Garynmike]

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....