The powers of EV's

[robinessex]

I have diddly squat interest in EVs, but the power outputs 'worry' me. Any PH knows a Lambo Aventador with circa 700bhp is bloody fast, and even with TC, needs some respect, caution, and I dare I say, skill. Yet anyone can pop into a Tesla showroom, and come out with a model X with 1000bhp, with a 0-60 time of 2.5 secs (1g). I hope its got some bloody impressive CT preventing Sharon, in a late dash take taking kids to school, doesn't floor it on a wet greasy road, and ends up inverted somewhere. Why not limit the power output to extend the range? I'm also puzzled about how the insurance companies are handling this. Henry is lurking in my garage with 400 supercharged bhp, he can be a bit naughty if you get a bit too enthusiastic. Don't ask me how I know.

[robinessex]

ChocolateFrog said:

The same crap is spouted about bikes.

"Ooh don't get the litre bike straight after you've passed your test, you'll kill yourself".

The great thing about throttles is they're not binary switches.

Scariest vehicle I've ever owned was a 50cc scooter with about 10hp that had a tendency to ice its carbs at around 1-3 degrees. Throttle would stick wide open, was okay controlling it on the brakes until they overheated and faded, then had to control speed via the ignition switch.

Was 16 and I never crashed it. First bike after passing my proper test had 1200cc and a sub 4s 0 to 60, never crashed that either.

As an ex-biker myself, I put motorcyclists in a different category, as we all know, get it wrong and you are history. Observing drivers in my locality with large 4x4s, I doubt their driving ability is much more than they needed to pass the driving test.

[robinessex]

smn159 said:

Anyone with the cash can buy an Aventador / 911 / Ferrari / whatever too. Are you worried about the power levels of those?

Are you arguing that all powerful cars should be limited in some way?

You've totally missed the point. I presume that most who buy an, acknowledged, high-performance sports car know what it's capable of and how to respect it. No problem with that. But EVs seem to be more of a transport device to take me where I want to go, and many I suspect who get to drive one has no idea of the power output, and what can go wrong.

[robinessex]

RizzoTheRat said:

I suspect the number of people who can pop in to a Tesla showroom and buy a £100,000+ car may be lower than you think

My local Sainsbury car park on a Saturday is regularly populated by +£100,000 vehicles. All the way up to 2 Lambo Urus last Saturday.

[robinessex]

JD said:

robinessex said:

You've totally missed the point.

You don't have one you, you just don't like change so must find a way to have a problem with it.

No, I'm happy with what I've got. What others have and enjoy doesn't interest me? I'm just making an observation.

[robinessex]

smn159 said:

robinessex said:

smn159 said:

Anyone with the cash can buy an Aventador / 911 / Ferrari / whatever too. Are you worried about the power levels of those?

Are you arguing that all powerful cars should be limited in some way?

You've totally missed the point. I presume that most who buy an, acknowledged, high-performance sports car know what it's capable of and how to respect it. No problem with that. But EVs seem to be more of a transport device to take me where I want to go, and many I suspect who get to drive one has no idea of the power output, and what can go wrong.

There's no qualification needed to buy a performance car other than the cash. How are those buying Lambos somehow more skilled than those buying Teslas?

Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?

[robinessex]

raspy said:

robinessex said:

My local Sainsbury car park on a Saturday is regularly populated by +£100,000 vehicles. All the way up to 2 Lambo Urus last Saturday.

That's very useful to know. Although I am curious, if they are wealthy enough to afford really high end cars, why are they shopping at Sainsburys?

Probably because we don't have an Aldi or a Lidl I suppose.

[robinessex]

sjg said:

robinessex said:

Why not limit the power output to extend the range?

It doesn't work like that with EVs. As petrol engines get more powerful they get less efficient - more capacity, heavier parts moving, more heat loss. The motors Tesla use are over 90% efficient (ie more than 90% of the energy in gets turned into motion) and it doesn't matter how fast or slow you're going to get that.

The biggest reason the performance models get less rated range is bigger wheels and stickier tyres.

Just put a current/voltage limiter in the motor software.

[robinessex]

aizvara said:

robinessex said:

Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?

I don't know about Teslas but my partially electric driven car has various modes including those for normal, round town driving, off road, and "sport". Those massively affect throttle response, steering feel,driven wheels, and similar. That's with a third of the power of the Tesla you mention but I imagine it isn't beyond the wit of their engineers to build a similar system for drivability in a range of scenarios.

Would be helpful if it defaulted to plod mode every time it was started up. The battery only has a finite amount of Kw/hrs. Modest power extraction should result in a longer range.

[robinessex]

Maracus said:

robinessex said:

aizvara said:

robinessex said:

Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?

I don't know about Teslas but my partially electric driven car has various modes including those for normal, round town driving, off road, and "sport". Those massively affect throttle response, steering feel,driven wheels, and similar. That's with a third of the power of the Tesla you mention but I imagine it isn't beyond the wit of their engineers to build a similar system for drivability in a range of scenarios.

Would be helpful if it defaulted to plod mode every time it was started up. The battery only has a finite amount of Kw/hrs. Modest power extraction should result in a longer range.

Personally, we charge 99% at home, and never get near any range anxiety. I wouldn't want the car to default to Chill or Green Plus unless I was approaching a single figure % and wasn't confident I could get a charge, which hasn't happened in 3 years.

Surely a 4x4 with 250hp would be sufficient?

[robinessex]

aizvara said:

robinessex said:

Surely a 4x4 with 250hp would be sufficient?

Sounds a bit boring.

I said sufficient. 1000bhp seems a bit OT.

[robinessex]

smn159 said:

robinessex said:

Surely a 4x4 with 250hp would be sufficient?

So why do you have a supercharged 400bhp [whatever] in the garage?

You seem to be suggesting that it's OK for richer blokes to drive powerful cars with no training, but anyone else - not so much, particularly if they're a woman.

You "seemed" wrong

[robinessex]

GT9 said:

What this means is that the motor cannot deliver full power from standstill, it can only deliver full torque.

Valid points, as you say, there is a difference. Just to be pedantic, Mr Newton worked out many years ago you require a FORCE to move (accelerate) a mass. That force in a vehicle is TORQUE. You can mimic it in an ICE car, with a torque conveyor, by full revs with the brakes on, and then releasing them.

[robinessex]

Diderot said:

robinessex said:

Maracus said:

robinessex said:

aizvara said:

robinessex said:

Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?

I don't know about Teslas but my partially electric driven car has various modes including those for normal, round town driving, off road, and "sport". Those massively affect throttle response, steering feel,driven wheels, and similar. That's with a third of the power of the Tesla you mention but I imagine it isn't beyond the wit of their engineers to build a similar system for drivability in a range of scenarios.

Would be helpful if it defaulted to plod mode every time it was started up. The battery only has a finite amount of Kw/hrs. Modest power extraction should result in a longer range.

Personally, we charge 99% at home, and never get near any range anxiety. I wouldn't want the car to default to Chill or Green Plus unless I was approaching a single figure % and wasn't confident I could get a charge, which hasn't happened in 3 years.

Surely a 4x4 with 250hp would be sufficient?

Hand in your PH card Rob. . My Ovlov BEV has 408bhp. Each and every horse is essential of course.

One thing that took me a little by surprise on the test drive was not so much the BHP - I’ve had more powerful cars before - rather the instant torque when overtaking.

I'll keep my PH card. Henry is getting a bit excited in his garage at the moment, as he might get a supercharger upgrade in spring.

[robinessex]

JD said:

robinessex said:

What others have and enjoy doesn't interest me?

robinessex said:

I have diddly squat interest in EVs, but the power outputs 'worry' me.

Which is it, you don't care or you do?

Your old fashioned 400bhp snotter is far more of a liability to others on the road than an modern EV

All the 'liability' I see on the roads seems to be the fault of the driver, independent of the type of vehicle they drive.

[robinessex]

Discombobulate said:

EV owners are not morons.

The driver who planted one in a front garden near me in the snow wasn't. Didn't comprehend that lots of go didn't equate to lots of whoa.

[robinessex]

Undercover McNoName said:

robinessex said:

I'll keep my PH card. Henry is getting a bit excited in his garage at the moment, as he might get a supercharger upgrade in spring.

And how is that not OTT then, as put by yourself?

It's not 1000bhp though, is it?

[robinessex]

Terminator X said:

Disappointed, I thought this thread would be about the magical powers of EV.

TX.

Not in PH anymore. Many have nowt to contribute to the room title, so resort to pointless, off-subject injections.

[robinessex]

GT9 said:

robinessex said:

It's not 1000bhp though, is it?

Which 1000 bhp EVs give you access to that power below speeds where you can actually use it?

I guess TC kicks in, but as pointed out a few postings ago, an EV can get out of control.

From Tesla website Model X

0-60 2.5 sec (+1g), "that maintains 1000+ hp all the way to top speed"

Edited by robinessex on Thursday 16th March 14:21

[robinessex]

GT9 said:

robinessex said:

I guess TC kicks in, but as pointed out a few postings ago, an EV can get out of control.

I don't think you've absorbed what I posted earlier.

It's got nothing to do with traction control.

It's inherent in the design of the drivetrain.

Here is the power curve for one of the most notorious 1000 bhp EVs.

Full power in NEVER available below 60 mph.

I'm guessing that's what I enquired about, the motor control system limits current and volts. An electric motor will draw much more current when stalled than when running. This is because when running, it is also acting as a generator, creating an EMF which opposes the applied EMF and reduces the overall current. A DC compound motor can run in series or shunt configuration, a bit like underground trains do. IN a DC shunt motor, torque is proportional to armature current. For a series-wound DC motor, torque increases as the square of the armature current.