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Discussion Starter · #1 ·
Hi! Just got a 2006 Ford e450 shuttle bus with an eldorado 15 passenger shuttle bus chassis. Not into how much gas it takes!
I want to convert it to electric, with flexi solar panels all over the massive roof.
Not to sure where to start, took some ev classes at the local community college a couple years back, but learned very little. Hoping this community has more practical expertise!
 

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The practical truth is

no matter if you maximise all possible solar collection

it won't be enough energy even in ideal conditions to get you more than a few miles down the road.

To overcome this you need a vehicle that weighs in total, less than the many thousand$ worth of batteries you need just to get started on your "dream".
Sky Solar vehicle Automotive tire Vehicle Road surface
 

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Now, grid power charging

You might get a 30-50mile range with a ton of batteries

So no road trips out into areas not yet densely served by EVSEs.

And really, such a heavy vehicle is just silly to convert to EV

from a practical POV.

sorry...
 

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Discussion Starter · #4 ·
There are actually a number of electric shuttle busses out there, and even kits to convert. I think you might be living in the past.
I understand that panels won’t just give me a free ride, but I also will be parking for days or weeks at a time, and prefer free energy rather than just not.
 

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You need a big ass motor and a shed load of batteries. The solar should be your final goal. I am intrigued by large vehicles for EV conversions because they have lots of room and payload capacity for lots, and lots of batteries. For a vehicle like that I'd count on 1 mile/kwh as your best case scenario and it will go down from there.
 

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Yes of course it "can" be done

but only for looping around locally, short range between known charging stations.

Not for road trips hundreds of miles out of town.

Sticking to coastal Southern CA might do it. But the utility achieved vs the cost$ time and trouble, seems just silly to me.

Now the great rural EVSE buildout is nigh, so if the conversion takes 5+ years for you to complete things maybe will align.
 

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Actually, the buildout of CCS charging stations over the past year or so has dramatically improved to where you could possibly go cross country with 100 miles of range (stay out of Wyoming, lol).

I for one cease enjoying trip legs of more than 300-400 miles, so 2 or three charging stops is not outrageous (lunch & dinner stops, then solar when parked for a few days). It becomes even better if you dinghy (flat) tow a BEV behind it and use the bus as a hub.

If one was retired going from RV to RV park, I can see it being a very viable use model. Beats the idiocy of a $175,000 turbodiesel bus dinghy towing a Jeep Cherokee, imo.

And, as you said, a couple or three years to complete a build is "going to where the puck will be" (Wayne Gretzky).
 

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Sorry 100mi range is absolute fantasy. Maybe, if you completely filled the interior with $100K worth of batteries but of course as the total gets ever heavier diminishing returns.

Even if you were willing to wait weeks for solar, total contribution might be 2%.

Positive thinking is nice, but must be tempered by some actual knowledge.

Which of course is why the forum exists
 

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This is super rough, but better than the crickets we have so far.

F450 is only rated to ~14,000lb GVWR, iirc. The engines in them were 235HP 7.2L diesels. That's 300kW full power up a steep grade, say 6%, at 60mph.

That increase in grade requires about 840 pounds of force, assuming Ford didn't design for gross towing weight. Assume 30" tires...about 1000ft lb. Back that into a 4.56 rear end ratio, direct drive turns ratio is 219 ft lb. Guess it at 2500 RPM gets us 104HP or about 130kW.

Backing that out of the 300kW leaves us with 170kW used at 60MPH if we assume Ford designd the e/f-450 to climb a 6% grade at highway speed at rated GVW.

A lot of assumptions.

Now, to get 100 miles of range, we need 1.67*170 or about 280kWh of battery. Call it 300kWhr for a 90% battery to motive power efficiency. Most of the new chargers are 350kW, so charge in an hour and a bit. Deploy a 3kW solar system at your stops for 6hr a day, and you self charge in...half a month.

3 Tesla 100 packs to go 100miles at full GVWR. 48 modules at 55lb is about 2600lb...call it 3000lb boxed.

That leaves 11,000 lb of curb weight plus payload.

So, it is feasible. $60 grand in batteries, though. A bit cheaper if you go with other choices like Leaf.

Would you rather have $100,000 in an electrified E450 conversion not counting donor and interior work, or pay the same (about $150-175,000) for a diesel motor home?

Yes, you need to stop every hour. But so does Greyhound, lol.
 

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F450 is only rated to ~14,000lb GVWR, iirc. The engines in them were 235HP 7.2L diesels. That's 300kW full power up a steep grade, say 6%, at 60mph.
It's apparently an E-450 (E-Series (formerly Econoline) van cutaway), not an F-450 (SuperDuty chassis-cab). Still, the model numbering corresponds roughly to the truck GVW classification and the E-450 barely makes it into the implied class (4) so about 14,500 pounds is right (the GCWR is much higher, so it belongs in the class) and it's roughly comparable in weight to an F-450.

The E-450 has come with various engines, in the last generation covering just about every engine found in medium-duty trucks. Yes, 235 HP would be common, but that's 175 kW (not 300 kW).

That increase in grade requires about 840 pounds of force, assuming Ford didn't design for gross towing weight. Assume 30" tires...about 1000ft lb. Back that into a 4.56 rear end ratio, direct drive turns ratio is 219 ft lb. Guess it at 2500 RPM gets us 104HP or about 130kW.

Backing that out of the 300kW leaves us with 170kW used at 60MPH if we assume Ford designd the e/f-450 to climb a 6% grade at highway speed at rated GVW.
Aside from the erroneous value of 300 kW, I see no reason to assume that any vehicle manufacturer would assume a requirement to maintain 60 MPH up a 6% grade at GVWR. Drive in any mountain area, and you'll find lots of trucks working all-out to maintain much lower speeds up the grades.

An easier way to calculate the power required to climb is to look at the rate of change of potential energy. Energy due to height is the product of weight and height. 60 miles per hour is one mile (5280 feet) per minute or 5280/60 = 88 ft/s; 6% of that multiplied by 14,500 pounds is 76560 lb-ft/s. One horsepower is 550 lb-ft/s, so that's 139 HP, or 104 kW. It's easier (no weird factors to remember) in metric units.

Tire size and axle ratio matter to what combination of torque and speed is needed to drive the shaft, but not the power required.

If the guess of 1 kWh/mile is correct for the energy needed to keep moving against aero and rolling drag, that's 60 kW at one mile per minute, or 164 kW to maintain 60 MPH up a 6% grade... coincidentally about the peak rating the of the example engine.
 

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Discussion Starter · #12 ·
Thank you Brian, that makes much more sense. One thing I’m also confused about is GVWR vs curb weight. My understanding is GVWR is the maximum allowable weight, including passengers, cargo, and tow. The curb weight is full tank of gas, no driver or cargo. Hard to find the actual weight without a trip to the dump.
Also consider the 1,500lbs of engine, transmission, and fuel would not be present, not to mention the 15-20 passengers weighing ~3,000lbs it is designed to carry, and the foldaway bench seats weighing ~400lbs.
I don’t have a ton of stuff, but I might have half a ton of stuff say +1,000lbs. Truly guessing here, but I imagine the GVWR includes people’s luggage too, and a bit of flexibility.
The point is, it wouldn’t actually weigh 14,050lbs.
And obviously I wouldn’t be charging with just solar, that’s just a bonus. It would be flexible panels glued and taped to the top, so there’s no “deploying” either. And fwiw the tires are 16”, not 30”
I am new to this, and not confident in making calculations, but for reference, these already exist: Products – Phoenix Motor Cars
Also, I hope this doesn’t ruffle any feathers, but I would want to use LiFePo4 batteries. I’ve already reached out to a group in Sacramento who does EV conversions, and they didn’t bat an eyelash at this idea, and in fact have done these conversions themselves.
Hope this helps!
 

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One thing I’m also confused about is GVWR vs curb weight. My understanding is GVWR is the maximum allowable weight, including passengers, cargo, and tow. The curb weight is full tank of gas, no driver or cargo. Hard to find the actual weight without a trip to the dump.
Close, and maybe correct depending on whose terminology you use...
  • Curb weight is with full tank of gas, no driver or cargo (or trailer)
  • Gross Vehicle Weight Rating (GVWR) is the maximum allowable weight, including passengers, cargo
  • Gross Combination Weight Rating (GCWR) is the maximum allowable weight, including passengers, cargo, and anything towed
In some commercial truck contexts, GCWR is referred to as GVWR and no separate GVWR is considered. For an E-450, about 14,000 pounds is the GVWR, not GCWR (resulting from front and rear axle load ratings - GAWR - of about 5,000 and 9,000 pounds).

Actual weight is easy because there are lots of scales. Yes, you can use a dump, or a commercial truck scale (where they charge for an accurate vehicle weight), or highways scales used for commercial vehicle enforcement (and in some areas freely available for any vehicle).

Also consider the 1,500lbs of engine, transmission, and fuel would not be present, not to mention the 15-20 passengers weighing ~3,000lbs it is designed to carry, and the foldaway bench seats weighing ~400lbs.
I don’t have a ton of stuff, but I might have half a ton of stuff say +1,000lbs. Truly guessing here, but I imagine the GVWR includes people’s luggage too, and a bit of flexibility.
The point is, it wouldn’t actually weigh 14,050lbs.
Any conversion to EV of any type or size of vehicle causes a net increase in mass if it has significant range, due to the required battery size.

Conversion from passenger to RV service (which is the goal, I assume) is unlikely to decrease empty weight, but the stuff you carry in it may be lighter than a full load of passengers and luggage. Due to water (and later waste), RVs routinely operate near GVWR, including Class C motorhome built on the E-450 (which is why they use the E-450 instead of the lighter and less expensive E-350). If you use it as a mobile tent (a big empty box with no cabinets, no appliances, no plumbing) it would be lighter... and pointless.

I think that it is reasonable to plan on the basis of the weight being close to GVWR.

I am new to this, and not confident in making calculations, but for reference, these already exist: Products – Phoenix Motor Cars
Yes, lots of conversion of this vehicle have been done, and the most effective way to get a good conversion is probably to buy a used one, since institutional and commercial operators have been known to buy "green" vehicles for political reasons and quietly retire them a few years later.

And fwiw the tires are 16”, not 30”
The earlier reference to tire size was the overall diameter (which is what is relevant to gearing calculations), not the nominal wheel diameter (which is irrelevant to gearing calculations).

Also, I hope this doesn’t ruffle any feathers, but I would want to use LiFePo4 batteries.
While some EV manufacturers use LiFePO4, most EV manufacturers and most EV conversions do not. I don't see a reason to worry about ruffling feathers.
 

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GVWR is payload plus curb, wet max. GCWR includes tow.

FWIW, unless you are using boat trailer TIRES, an E-450 is not even close to 16"...that's the wheel (rim) size.

Vehicle testing to establish weight rating includes cooling and brake sizing as well as horsepower to maintain grade. Testing is performed in areas like Vale Pass that have extended grades. Competition would laugh you out if town if you release a vehicle that can't keep truck speed on Interstates at GVWR. Semis are apples to oranges in hill climbs.

Given that you need close to a quarter megawatt hour of mobile storage, a heavier battery tech is a huge mistake...you have to lift that up every incline, no matter how slight. Your project, your wallet, your incitement of roadrage as you climb a grade at 25mph on a two lane 55.
 
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