EV are they worth it?

[Avocet]

It just shows your lack of experience. I did something like the first video a few times: reverse, clutch down brake down to stop, hand brake on, clutch up. Boom, unexpected reverse.

Are you sure you should be in possession of a driving licence?!

But engine stalls and saves the day, as demonstrated by the woman in the video.

Oh... is that what happened? Or was it simply a rear wheel drive car that no longer had its driving wheels on terra firma? Tell me... why did it "stall" after it had smashed through the wall?

I would place that as excessive complexity in a reverse and stop scenario.

Are you absolutely SURE you should be in possession of a driving licence?!

In an EV, it would have accelerated to 70 mph and the woman would have ended up in a lower level of the car park across the road!

I know showing your ignorance is something of a badge of honour for you on these fora, but you do realise that EVs are speed-limited in reverse, don't you?

 

[Avocet]

This certainly explains the crashes. In an ICE car, even if the brakes fail, the diver could still clutch down to terminate the acceleration.

Or at least... in the ICE cars with clutch pedals, they could...

 

[IT Minion]

This certainly explains the crashes. In an ICE car, even if the brakes fail, the diver could still clutch down to terminate the acceleration.

Yes, driver error does explain the issues.

It's not impossible that there's a bug that resulted in uncommanded acceleration, or that the brakes didn't trigger when someone stamped on the pedal, but it hasn't been demonstrated. And for those of us who can't read the Matrix directly it's not possible to tell from CCTV if it is driver mistakes or a faulty car.

 

[DiyNutJob]

Oh... is that what happened? Or was it simply a rear wheel drive car that no longer had its driving wheels on terra firma? Tell me... why did it "stall" after it had smashed through the wall?

The car stopped before the wheel went over the edge. Likely stalled at that moment. The residual momentum then pushed the car over the edge.

 

[DiyNutJob]

Yes, driver error does explain the issues.

It's not impossible that there's a bug that resulted in uncommanded acceleration, or that the brakes didn't trigger when someone stamped on the pedal, but it hasn't been demonstrated. And for those of us who can't read the Matrix directly it's not possible to tell from CCTV if it is driver mistakes or a faulty car.

The videos show the natural driving characteristics of the cars. They are identical, hence defective drive by wire. The software layer is faulty.

 

[Avocet]

The car stopped before the wheel went over the edge. Likely stalled at that moment. The residual momentum then pushed the car over the edge.

Rubbish! If the car had stopped before the back wheels went over the edge, why did the back wheels go over the edge? Once something has stopped, it has no momentum (which is the product of mass and velocity).

 

[Deleted member 174758]

One question about these modern cars: Why, unlike say industrial machinery, CNC routers and milling machines, etc did the designers not think to install a mechanical isolator? On a CNC router, for example, there is generally a key switch on the controller plus several emergency stop buttons, one at every operator "station", where pressing the stop button breaks the power to the motors and the brakes (default position "on" and only held off when you have power, compressed air and vacuum and all the other safety interlocks, such as safety fences, pressure mats, etc are "clear") are applied to the axis motors? Rather a wrecked cutter and bed than a runaway which could kiil someone. This is a common approach in industrial applications (although every case is unique). Or is this just a pointless, naive question to ask?

At the end of the day in an old fashioned key operated ignition switch turning off the switch would simply kill the engine (no power = no spark) whilst on diesels it should either isolate the electric fuel pump or in the case of mechanical fuel pumps cut the power to a normally closed solenoid valve in the fuel line (although the number of runaway engine fires in VW diesel cars in the 1970s and early 80s showed that even the bright sparks at VW hadn't thought that one through thoroughly)

 

[Avocet]

One question about these modern cars: Why, unlike say industrial machinery, CNC routers and milling machines, etc did the designers not think to install a mechanical isolator? On a CNC router, for example, there is generally a key switch on the controller plus several emergency stop buttons, one at every operator "station", where pressing the stop button breaks the power to the motors and the brakes (default position "on" and only held off when you have power, compressed air and vacuum and all the other safety interlocks, such as safety fences, pressure mats, etc are "clear") are applied to the axis motors? Rather a wrecked cutter and bed than a runaway which could kiil someone. This is a common approach in industrial applications (although every case is unique). Or is this just a pointless, naive question to ask?

At the end of the day in an old fashioned key operated ignition switch turning off the switch would simply kill the engine (no power = no spark) whilst on diesels it should either isolate the electric fuel pump or in the case of mechanical fuel pumps cut the power to a normally closed solenoid valve in the fuel line (although the number of runaway engine fires in VW diesel cars in the 1970s and early 80s showed that even the bright sparks at VW hadn't thought that one through thoroughly)

I think it's because it's easier to do electronically in a crash situation. The batteries have a battery management system which will make various safety checks (in terms of cell health and leakage to earth, etc) whenever you try to "start" the car. If all is well, the battery management system will tell the "contactors" to close, and allow high voltage through to the inverter. If, during driving, a serious safety-critical fault occurs, it will open them again. The other situation, is a crash scenario. In that instance, the battery management system is connected to the airbag trigger system, so if you hit anything hard enough to trigger an airbag, the contactors have top open. In fact, post-crash test, there's a requirement for the battery to split itself (at least with certain configurations of battery pack), into groups of cells with a potential of no more than 60 Volts DC. In that case, there will be several contactors within the battery pack. As far as your original question is concerned, therefore, I think it's just the route car manufacturers have gone down, in their search for a compromise between having the most convenient driving experience, and meeting the various regulatory requirements for safety.

 

[bernardgreen]

Quote from https://www.bedsfire.gov.uk/Community-safety/Road-safety/Fire-in-Electric-Vehicles.aspx

Putting out the fire

For the fire brigade, the real problem when it comes to an EV fire is with trying to put it out.

The services have two main options, let the fire burn out or extinguish it.

The obvious choice seems to be to extinguish the fire, however many EV manufacturers actually advise for a controlled burn. This is where the fire services allow the vehicle to burn out while they focus on protecting the surrounding area.

Once the fire has been successfully put out, the problem for the fire brigade is not over.

Electric vehicle fires are known to reignite hours, days or even weeks after the initial event, and they can do so many times.

Not only does this pose a safety issue, but it also poses a legal issue: recovery firms are increasingly concerned about dealing with electric vehicles.

 

[Deleted member 174758]

That's rather worrying, at least to me. The reason why manufacturers of industrial equipment use mechanical isolation is because it works even in the event of a total power failure - and it is actually mandated in H&S law. I'm surprised this hasn't translated into the EV market

 

[Deleted member 174758]

Not only does this pose a safety issue, but it also poses a legal issue: recovery firms are increasingly concerned about dealing with electric vehicles.

That explains why one recovery outfit in this vicinity has recently taken on a new flat bed recovery truck with a stainless steel body (as opposed to aluminium) and a rather large BCF suppression system (6 large extinguishers as opposed to the standard 2). They charge a premium for its' use as well as for storage of recovered EVs in their yard where they now have a couple of walled, concrete floored bays. Apparently this was done after a recovered EV set fire to a whole yard full of ICE vehicles at one recovery outfit, at which point the insurers insisted, or so one of the drivers told me (he also said this new vehicle is so heavy that it requires a class 2 licence, so over 7.5 tonnes)

 

[Avocet]

Quote from https://www.bedsfire.gov.uk/Community-safety/Road-safety/Fire-in-Electric-Vehicles.aspx

Putting out the fire

For the fire brigade, the real problem when it comes to an EV fire is with trying to put it out.

The services have two main options, let the fire burn out or extinguish it.

The obvious choice seems to be to extinguish the fire, however many EV manufacturers actually advise for a controlled burn. This is where the fire services allow the vehicle to burn out while they focus on protecting the surrounding area.

Once the fire has been successfully put out, the problem for the fire brigade is not over.

Electric vehicle fires are known to reignite hours, days or even weeks after the initial event, and they can do so many times.

Not only does this pose a safety issue, but it also poses a legal issue: recovery firms are increasingly concerned about dealing with electric vehicles.

It's a known issue, and solutions are being developed all the time. It's a fast-moving area. Despite all the hysteria though, they don't seem to catch fire as often as ICE vehicles do, and unlike burning ICE vehicles, you don't have the problem of burning liquid fuel running all over the road under other vehicles.

Where there's a will... & all that!

Container puts out inextinguishable fires in electric cars - CFPA Europe

The lithium-ion batteries in electric and hybrid cars present a challenge […]

cfpa-e.eu

 

[Avocet]

That's rather worrying, at least to me. The reason why manufacturers of industrial equipment use mechanical isolation is because it works even in the event of a total power failure - and it is actually mandated in H&S law. I'm surprised this hasn't translated into the EV market

I'd be a lot more worried about the situation where I'm unconscious after an accident and my car is still "live"!

 

[IT Minion]

I'd be a lot more worried about the situation where I'm unconscious after an accident and my car is still "live"!

EVs are better at protecting you during a crash. There's no giant hunk of steel engine block so the crumple zones are less limited. There's footage of people walking away from frontal Tesla crashes at 93mph.

There's less room to improve over ICEs for side impacts though.

Have a look at the NCAP scores for EVs here:

Electric Vehicles | Euro NCAP

Find the safety ratings of full-electric cars tested by Euro NCAP. These results are arranged by the year of test and by star rating.

www.euroncap.com

The only ones that score poorly are the ones based on ICE vehicles, the Zoe is based on the Clio and the Dacia spring on the Kwid.

 

[Avocet]

EVs are better at protecting you during a crash. There's no giant hunk of steel engine block so the crumple zones are less limited. There's footage of people walking away from frontal Tesla crashes at 93mph.

There's less room to improve over ICEs for side impacts though.

Have a look at the NCAP scores for EVs here:

Electric Vehicles | Euro NCAP

Find the safety ratings of full-electric cars tested by Euro NCAP. These results are arranged by the year of test and by star rating.

www.euroncap.com

The only ones that score poorly are the ones based on ICE vehicles, the Zoe is based on the Clio and the Dacia spring on the Kwid.

Meh... I'm agnostic on that one. The giant hunk of engine block is actually a big chunk of weight which, once it has hit the wall, isn't part of the mass being decelerated (unless you're in a Porsche 911 or something else with the engine behind you)! It's also a convenient "wall" between you and whatever you hit - particularly in a transverse-engined layout. Handy, if what you hit, happens to be a telegraph pole! EV manufacturers are hampered by the massive eight of the battery and the fact that there are regulations on what can and can't happen to it in the crash tests. It's part of the reason EVs aren't lighter than they currently are. I certainly don't see them as significantly more dangerous, but I don't see them as safer either. Just "different". The regulatory framework for EVs is struggling to keep up with developments in the field, with it being such a new technology.