Question for engineers and EV geeks: What are the advantages for a car being designed as a BEV only?

Hello, all. 1st time poster. I wanted to ask what the advantages of a BEV only car design are. PHEVs are not of interest as they also have thermal engines, but if you can give me some insight on those, it would be highly appreciated.

Thank you in advance and looking forward an intelligent discussion!DELETED SPAM LINKS

gammy13 said:

Hello, all. 1st time poster.

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Not really. You have this thread
https://endless-sphere.com/forums/viewtopic.php?f=7&t=101951
that you never bothered to come back to.

Regarding the BEV question, I don't really understand what you mean. Advantages and disadvantages of anything are specific to the intended use.

So...what do you want to use it for?

They are easier to construct, should be lighter and cheaper. In a hybrid, you have the electro motor and the other one.
In an all EV you just have one or more electro motors. A full EV will need a bigger battery and might need some planning for longer trips as the car will need to be charged. In our country, people (usually firms) buy hybrids so they can profit from tax reductions by riding more environmental friendly. They usually don't take their charger cable out of it's package. The range you can go full electric on a hybrid is much smaller.

obcd said:

They are easier to construct, should be lighter and cheaper. I

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Odd that it doesn’t seem to work out like that ?

gammy13 said:

Hello, all. 1st time poster. I wanted to ask what the advantages of a BEV only car design are. PHEVs are not of interest as they also have thermal engines, but if you can give me some insight on those, it would be highly appreciated.

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With a BEV:

Minimized thermal management. You have to keep inverter, charger and battery cool, but they don't operate with >500F components so it's a lot less work. (Downside - since an EV is very efficient it doesn't generate a lot of heat, so you don't have "free" heat available for keeping the battery warm, defrosting the windshield etc)

Lower center of gravity. Almost all BEV's mount the batteries low, which greatly improves handling and simplifies suspension design.

Greater freedom of placement of components. Batteries can be almost anywhere and are easily massaged to provide space for struts, torsion arms, anti-sway bars etc and they can be distributed throughout the vehicle. Motors do not need any specific orientation.

Little need for vibration isolation. Motor mount design is simpler since there's less vibration to isolate from the chassis.

Batteries and motors can't be almost anywhere unless you don't mind having the handling of a forklift. Batteries need to be low and centralized, which is also where the people want to be. You can make them part of the structure but only if you are confident they will never need replacement.
Motors end up near the axles and inboard. The spot where cargo usually goes. So if you go with an AWD setup like many EVs then you sacrifice cargo space.

All of which adds up to vehicles which are neither cheaper nor lighter unless you count golf karts.

There's recently been a couple of videos posted that pit a Ford F150 4X4 truck against models of Teslas in a tug-of-war contest, and the Ford loses badly. It's an unfair comparison, but it does highlight that the EV's have their full torque at one RPM. Gasoline engines make their best peak horsepower at higher RPM's, so the Ford never was able to use it's full power.

The main issue is that when a truck has an empty bed, the rear wheels have very little traction, and have a tendency to spin out. The Teslas all had an even weight distribution (so all four wheels have equal traction), along with electronic traction-control on all wheels preventing a spin-out. If they had added weight to the truck-bed, it would improve traction contests, even while slowing it's 0-60 speeds.

EV's have a more reliable cold-weather start-up. Batteries perform poorly when cold, but once you start driving, the system can warm the batteries up to the optimum temperature. Tesla's are VERY popular in Scandinavia, where it is brutally cold in the winter.

If you someday add a huge solar-panel array to your home, you could theoretically charge your car from your home's back-up battery. I do understand that it causes pollution to mine the materials and also manufacture the panels and batteries, but...if there is ever a large glitch in the supply of fuels, a solar-charged EV will always have "fuel", even if there is no more gasoline for a while...

The battery pack in an EV is very large. In a temporary power-outage, you can power your TV, phone, laptop, and some lights from your cars battery pack.

spinningmagnets said:

There's recently been a couple of videos posted that pit a Ford F150 4X4 truck against models of Teslas in a tug-of-war contest, and the Ford loses badly. It's an unfair comparison, but it does highlight that the EV's have their full torque at one RPM. Gasoline engines make their best peak horsepower at higher RPM's, so the Ford never was able to use it's full power.
The main issue is that when a truck has an empty bed, the rear wheels have very little traction, and have a tendency to spin out. The Teslas all had an even weight distribution (so all four wheels have equal traction), along with electronic traction-control on all wheels preventing a spin-out. If they had added weight to the truck-bed, it would improve traction contests, even while slowing it's 0-60 speeds.

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Not really.
It was an unfair comparison, but nothing to do with power, torque rpm , etc...
But simply because ..
A) the ford was only using 2WD
2) the Tesla is a much heavier truck
...those two factors gave the Tesla a huge traction advantage
[youtube]jzKCJsou10w[/youtube]

spinningmagnets said:

..EV's have a more reliable cold-weather start-up. Batteries perform poorly when cold, but once you start driving, the system can warm the batteries up to the optimum temperature. Tesla's are VERY popular in Scandinavia, where it is brutally cold in the winter...

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Teslas are popular in scandinavia because there are huge Government rebates available, and gasoline is very expensive

spinningmagnets said:

but...if there is ever a large glitch in the supply of fuels, a solar-charged EV will always have "fuel", even if there is no more gasoline for a while...

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Always? Not quite. Batteries have an end of life. Also, the situations that would result in "no more gasoline for a while" are very unlikely given the current glut and ever-expanding amount of reserves. If such an absence were to actually occur, the things that would have caused it would be more concerning than how we are supposed to make our cars go.

If I read your Q correct you are looking for advantages of a ground up design for BEV, rather then taking an existing platform designed for ICE and just remove all ICE part then bolt on an electric drive line and batterypack? Most obvious advantage from designing a BEV car as a BEV from the ground up would be to get close to perfect balance, lowest center of gravity, more cabin space and in general you could draw in space for whatever you need space for in the design. Rather the modifying and doing things like an after thought.

The first electric Ford Focus was like that, just a regular ICE where they swapped the ICE for batteries and electric motors.. Not a popular EV by sales. Most of the trunk space was used for batteries. Even if the battery took almost all usable trunk space it was a tiny EV batterypack. VW did the same with EV Golf. They did a better job then Ford did with their Focus but it was still obvious the car was an ICE with a strap op kit.

A later model was the Mercedes ECQ. They also "recycled" an ICE platform and strapped on electric drive line and batteries. Because of that the Mercedes had the tunnel for the drive shaft. Yet it has no drive shaft. So that tunnel is just eating up space inside the cabin. And there ain't no frunk either. Because they didn't design it as a BEV from the ground up. I've read others say that the center of gravity becomes worse due to the "double flooring", where batteries are hung from the underside of the floor panels, yet the battery pack most be enclosed in a rigid box. So you kind of get an extra layer of floor that just eat away cabin space. You can see and feel this in the ECQ. I don't know if that is correct, that the extra floor rises the COG but it sure eats away room for you feets etc.

Hillhater said:

Not really.
It was an unfair comparison, but nothing to do with power, torque rpm , etc...
But simply because ..
A) the ford was only using 2WD
2) the Tesla is a much heavier truck
...those two factors gave the Tesla a huge traction advantage

spinningmagnets said:

..EV's have a more reliable cold-weather start-up. Batteries perform poorly when cold, but once you start driving, the system can warm the batteries up to the optimum temperature. Tesla's are VERY popular in Scandinavia, where it is brutally cold in the winter...

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Teslas are popular in scandinavia because there are huge Government rebates available, and gasoline is very expensive

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You are right about the tugawar.

Btw. Gasoline should be expensive everywhere. The toll gasoline takes on our health and if you look into the amount of people dying from pollution each year gasoline should likely cost ten times more. Really forcing everyone over to EV's. But right wing extremists might not see it that way

And partly right about Tesla in the northern part of EU. Sure some great EV benefits especially in Norway. Zero tax on EV's and no VAT. But that goes for all EV's. I think the main reason Tesla has sold so well in Norway is that when Tesla first launched model S there was nothing like it. The very first electric family car. Even for families with only one car, yes those families do exist because cars are expensive and fuel as well. For the first time in history an BEV could fill all their needs, and due to no-tax-no-vat Tesla was obtainable for many people. Even buyers that traditionally owned say a VW Golf or a small Ford hatchback could suddenly charge for free and drive a huge sedan that felt luxurious. And they could even take the car on holidays. Even BMW and Mercedes buyers went green and got Tesla. Even after years of driving premium German luxury sedans or estates. And even if you have to wait half an hour at the supercharger, every day you leave your home your "tank is filled up". And no local black cloud of smoke from a diesel or toxic particles. Some bought in to the EV car because of the price tag. Many because they could get a fast car without being a toxic pig.

The rapid expansion of Tesla superchargers also played a big role. Easy to drive and charge for free across entire Europe. Heck, I remember even people that never was into cars before Tesla became car enthusiasts after getting a Tesla. Sooo roomy inside and so much room for luggage. Super fast acceleration. So cool but expensive. Then enter model 3. Now even more could afford to drive electric. And lets not forget the leaf. We have a lot of BEV Nissan Leaf's roaming the roads as well. MK II was a great upgrade and I know many happy owners of Leaf.

Yes there have been a BEV Jaguar and Audi that also are real nice cars but so far they haven't matched Tesla's sales. Those cars also get the same No VAT and No TAX. Over the next two years we will see a lot of new BEV cars. Many of them will target lower price point then what we've seen so far. And this time they have deigned their BEV's from the ground up as BEV's.

We will even see electric panel vans becoming more used. And bigger trucks. Electric trains with battery backup so they can run old tracks without 100% electric coverage. And this is partly due to the EU politic of forcing manufacturer more over to BEV or else....pay the price. Nice, once again the stick works better then the carrot.

This is truly exciting times. And we need even smaller and lighter EV's that get more range then what we have seen for their first try. This time it seems from the leaked spec sheets that even Skoda will make sure to have usable range, shared vw platform but lower price. Volvo, the french's and even several new Chinese models. I really think we will see a dramatic change over the next few years. And that is great for you and me and those little ones growing up.

Hillhater said:

spinningmagnets said:

There's recently been a couple of videos posted that pit a Ford F150 4X4 truck against models of Teslas in a tug-of-war contest, and the Ford loses badly. It's an unfair comparison, but it does highlight that the EV's have their full torque at one RPM. Gasoline engines make their best peak horsepower at higher RPM's, so the Ford never was able to use it's full power.

Click to expand...

Not really.
It was an unfair comparison, but nothing to do with power, torque rpm , etc...
But simply because ..
A) the ford was only using 2WD
2) the Tesla is a much heavier truck
...those two factors gave the Tesla a huge traction advantage

Click to expand...

Yes, really.

Spinningmagnets did not specify the video you linked, nor did he even mention the CyberTruck, he was very vague and mentioned "a couple of videos" that feature Teslas.
A quick google can confirm what he says is true, I'll save you the effort however.

Here's a video showing exactly what spinning magnets said:
F150 Raptor V Tesla X : https://youtu.be/VPNoXa-Lb_k?t=251 -- Tesla X wins (Raptor spinning all 4 wheels) - feel free to nitpick the weight though.

And because I don't care either way, have a video of a F250 beating a tesla X (well 2 out of 3 times).
F250 V Tesla X: https://youtu.be/kBqr5OMCXcI?t=367

Both are terribly produced videos that annoy the heck out of me as they're too busy trying to sell something that I'm not interested in.

No, not really, SM’s point was that the EV had more torque.
If You watched the video , or simply grasped the physics of it , you would understand that it is not about Torque at all...verified by the fact that the vehicles break traction
Its all about traction, and which vehicle has the most of it.
That will be determined by weight , weight distribution, tire choice, tire pressure, suspension set up , etc etc
......AND...driver technique !

Hillhater said:

That will be determined by weight , weight distribution, tire choice, tire pressure, suspension set up , etc etc
......AND...driver technique !

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The driving technique is a big part. So is the start. I notice that the Tesla frequently gets the initiative actually rolling the truck backwards before it can apply enough torque to either lock or spin its wheels. That gives a substantial inertia advantage to the Tesla. The right way to to this test would be with some like they do with tractor pulls. Or maybe better would be a practical test of towing a trailer up a hill or something similar. I wonder what happens to those electric motors in some real world situations where they are heavily loaded for extended time periods.

wturber said:

wonder what happens to those electric motors in some real world situations where they are heavily loaded for extended time periods.

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Nothing much I suspect. Thermal management will throttle back if need be. Heavily loaded is not a very precise term, but say loaded to max payload plus towing a trailer also at max weight up even steep climbs will go rather smooth I suspect. In the western part of Norway driving east up and over mountain passes I've spotted a few heavy loaded model x's, one of them I suspect was loaded past the legal limit of the weight to the trailer. But even in hot summer weather those x's made the steep climbs easily. The only other time I've seen that same type of camping trailer it was hauled by a large diesel 4x4 pickup. Iirc the weight of those are more then three tonn. I think the range will diminish quicker then the heating of the motors when hauling heavy loads up steep hills.

Did not go thru every post of "gammy13" but IT seems to start a post but never responds or post in it again just starts another one? What's up with that?

I was quite disappointed when GM discontinued the Chevy Volt. My son has one and we are both impressed by it. Most daily journeys for one member of the family are typically short. One example is that my spouse worked 8 miles from our home, so 16 miles each day, five days a week. Of course on week-ends we would usually travel farther for entertainment, visiting relatives, going to restaurants and shopping, but...we had two cars.

My wife was the perfect candidate for a 100-mile EV with only two seats.

The benefit of the Chevy Volt was that it had a gasoline engine for long journeys, so as a result, the battery pack only needed a small range, which saves size, weight, and cost on the battery pack. The Volt engine didn't need to be large for acceleration, because a small engine plus electric motor together provided excellent acceleration. My son operated it as an EV 90% of the time, and charged overnight at home.

When you order a BEV (Tesla, Chevy Bolt, Nissan Leaf) you typically have the option of a minimal battery pack to save weight and money, or a larger one for longer distance.

The comparison between a plug-in hybrid and a BEV would be the cost and complexity of the transmission and engine, compared to the cost of a large battery (minus the cost of the basic battery). Whether a given battery pack is small or large, it will be the part that wears out and needs to be replaced. A hybrid engine would be used rarely, and in theory, it should last decades. I have seen low-mileage cars from the 1930's that ran fine on the original engine.

A BEV drivetrain is pretty simple to design and build. If the car is involved in a wreck, it is highly likely that much of the drivetrain (if not all of it) can be salvaged and swapped-into a vintage gasoline car. I would guess that PHEV drivetrain would be very difficult to design, produce, and swap out...

ZeroEm said:

Did not go thru every post of "gammy13" but IT seems to start a post but never responds or post in it again just starts another one? What's up with that?

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gammy13 is a spammer. He posted 5 times here, then came back to edit his posts to add his spam links. I deleted his links but enough replied to him that I'm not going to delete his topic starter posts.

I get it keep the good info 8)

Simon, you seem to have missed a few points..
firstly, as pointed out above,..the op does not return to his threads !..
secondly, the biggest issue with BEVs is their high cost …
…closely followed by the fact that they actually increase emissions due to the amount of fossil energy needed to both produce them, mine the materials for the batterys and motors, and produce the electricity used to charge them ( still 80% fossil fueled)
. You should also ask Hertz about their experience with EV (Tesla) Operating, running , repair, and maintenance costs. !
Then consider resale values too.
The one real benefit of EVs is that they could reduce the consumption of oil slightly, hence saving it for critical uses such as diesel, industrial materials, chemicals, drugs etc.

ZeroEm said:

Did not go thru every post of "gammy13" but IT seems to start a post but never responds or post in it again just starts another one? What's up with that?

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Looks like a spammer beceause there are links hidden in the end of the posts.