Electric Vehicles etc

[rangersac]

It's a Leaf right? That's a very ICE concept, only charge the battery in "run" mode, and for no apparent reason. AFAIK Tesla's don't do that because they are on or off, there is no accessory mode.

Yeah first gen Leaf. No idea behind the concept, probably didn't want to run the traction battery down unnecessarily given the minimal range on the early cars.

Also, genuine question as I am not a car nerd, but when did regular jump starting become 'dangerous'? I've lost count of the number of cars I've jumped with regular leads, and have never had issues. Fair enough having a stand alone pack so you don't have to find another vehicle.

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[Stredda]

Yeah first gen Leaf. No idea behind the concept, probably didn't want to run the traction battery down unnecessarily given the minimal range on the early cars.

Also, genuine question as I am not a car nerd, but when did regular jump starting become 'dangerous'? I've lost count of the number of cars I've jumped with regular leads, and have never had issues. Fair enough having a stand alone pack so you don't have to find another vehicle.

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I've seen a whole heap of people getting stuck with a similar issue on the RAV4 page with the Hybrid models. Seems to be very common to have a flat 12v battery, especially the people who don't drive that often. Like a parasitic drain or something.

 

[Oddjob]

Yeah first gen Leaf. No idea behind the concept, probably didn't want to run the traction battery down unnecessarily given the minimal range on the early cars.

Also, genuine question as I am not a car nerd, but when did regular jump starting become 'dangerous'? I've lost count of the number of cars I've jumped with regular leads, and have never had issues. Fair enough having a stand alone pack so you don't have to find another vehicle.

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Jump starting became dangerous when cars had computers. An arc between a terminal and jump lead can and has cooked ECUs before a fuse can cut in.

The control units on those battery packs are specially designed to limit voltage and amperage. The jumper attachments also have diodes.

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[beeb]

Jump starting became dangerous when cars had computers. An arc between a terminal and jump lead can and has cooked ECUs before a fuse can cut in.

The actual danger with Lead Acid batteries is if they have recently experienced a high current draw (like during extended cranking when the vehicle won't start), and particularly if the battery has got low electrolyte levels or a dead cell - the battery can emits flammable/explosive vapour, and an arc while attaching a charger/ battery pack/jumper leads can cause them to explode. It's not common but does happen (I typically see it in work's "Safety Alert" incident reports a couple of times a year).

BTW - This includes "sealed" lead acid batteries, which quite often have breather ports under a comestic "sealed" cap. It's probably more common in the heavy vehicle sector where batteries are much higher capacity, but not impossible from light vehicle (car) batteries.

The additional problem is that it's not just potentially a face full of battery shrapnel, but also getting splashed with the battery acid at the same time.

 

[Oddjob]

The actual danger with Lead Acid batteries is if they have recently experienced a high current draw (like during extended cranking when the vehicle won't start), and particularly if the battery has got low electrolyte levels or a dead cell - the battery can emits flammable/explosive vapour, and an arc while attaching a charger/ battery pack/jumper leads can cause them to explode. It's not common but does happen (I typically see it in work's "Safety Alert" incident reports a couple of times a year).

BTW - This includes "sealed" lead acid batteries, which quite often have breather ports under a comestic "sealed" cap. It's probably more common in the heavy vehicle sector where batteries are much higher capacity, but not impossible from light vehicle (car) batteries.

The additional problem is that it's not just potentially a face full of battery shrapnel, but also getting splashed with the battery acid at the same time.

Wasn't aware of that one. I've only seen the fried ECUs, especially on older cars were the solder or board might be borderline.

In fact I haven't seen a modern EFI petrol motor fail to fire if there was enough electricity and petrol and the motor was intact. I've seen some old school diesels and big cylinder count motors need a second or two but that's it.

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[rangersac]

Thanks for the info. I kinda feel like if jumping was that risky then cars wouldn't have procedures for how to do it in their manuals. Anyway no harm done, battery appears to still be alive according to the indicator colour so hopefully the experience has educated the better half

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[beeb]

Thanks for the info. I kinda feel like if jumping was that risky then cars wouldn't have procedures for how to do it in their manuals. Anyway no harm done, battery appears to still be alive according to the indicator colour so hopefully the experience has educated the better half

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I'd not hesitate to jump start, but if the operator had been winding it over for an extended period I'd let it air off for a couple of minutes just to be safe. Chances of anything bad happening are extremely slim, but once you've seen some exploded batteries in person it does make you a bit more aware/cautious about it.

 

[Oddjob]

Thanks for the info. I kinda feel like if jumping was that risky then cars wouldn't have procedures for how to do it in their manuals. Anyway no harm done, battery appears to still be alive according to the indicator colour so hopefully the experience has educated the better half

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Who the fuck reads manuals (other than us)? And then actually spends the time and money to get proper protected jump cables and learn how to use them?

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[Dales Cannon]

Who the fuck reads manuals (other than us)? And then actually spends the time and money to get proper protected jump cables and learn how to use them?

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Even before modern electronics I saw a battery on a D7 explode all over the operator and a few bystanders. From that point on one neg lead always goes onto something far away from the battery.

 

[Flow-Rider]

It takes a lot to fry an ECU from jump starting, I've got over 35 years hands-on experience in workshops, Jump starting cars is an everyday event in a busy workshop, it's usually the cheap shit that blows, stuff like aftermarket LPG gas modules. I never had a fried ECU at my hands, not even once, only time I heard of an ECU blowing is when people connect with reverse polarity.

 

[Flow-Rider]

And for 12v sulphuric batteries blowing up, we had a battery on the charge with the caps off, with the electrolyte boiling and a dickhead auto electrician tried to test a solenoid on it, which ended up with a loud bang. He got battery acid in his eyes but we managed to wash out fast enough, with no long term damage. Other than home mechanics leaving screwed batteries on charge for days on end, that's the only other time I've heard of a lead acid battery blowing up in a real life situation.

 

[beeb]

And for 12v sulphuric batteries blowing up, we had a battery on the charge with the caps off, with the electrolyte boiling and a dickhead auto electrician tried to test a solenoid on it, which ended up with a loud bang. He got battery acid in his eyes but we managed to wash out fast enough, with no long term damage. Other than home mechanics leaving screwed batteries on charge for days on end, that's the only other time I've heard of a lead acid battery blowing up in a real life situation.

Gets more common once the CCA's get 1000+. Still rare though.

 

[Haakon]

 

[Calvin27]

Listened to this. Love the brands and their cars, but can't help feeling that this really felt like they are dinosaurs clinging onto their glory days. Almost felt like it was the old Nokia CEO saying no one wants a breakable touch screen phone. Also felt a little elitist, which is fair given the markets they sell to lol.

Don't get me wrong I would pick a mx5 over a tesla plaid any day for pure driver enjoyment, but I'm not too sure their position that hypercars will still be ICE will hold water for that much longer.

Dunno, I guess I was in disagreement with a lot of what they said, but hey I am neither the target market for their products or have as much knowledge and experience as those guys.

 

[Haakon]

Listened to this. Love the brands and their cars, but can't help feeling that this really felt like they are dinosaurs clinging onto their glory days. Almost felt like it was the old Nokia CEO saying no one wants a breakable touch screen phone. Also felt a little elitist, which is fair given the markets they sell to lol.

Don't get me wrong I would pick a mx5 over a tesla plaid any day for pure driver enjoyment, but I'm not too sure their position that hypercars will still be ICE will hold water for that much longer.

Dunno, I guess I was in disagreement with a lot of what they said, but hey I am neither the target market for their products or have as much knowledge and experience as those guys.

I thought the exact opposite on the EV stuff! Yeah, the whole "making aspirational/inspirational stuff is a service to humanity" was a bit of reverse justification for making silly things, id prefer the "we just like silly things" argument as more honest!

But their views on Tesla and Musk were refreshingly nuanced given the popularity of hating on him, and their understanding ICE is at best a niche toy now and mainstream transport must be electrified.

And Rimac is only 34 - he is in his glory days now!

 

[Calvin27]

the whole "making aspirational/inspirational stuff is a service to humanity" was a bit of reverse justification for making silly things, id prefer the "we just like silly things" argument as more honest!

That was so cringey lols.

But their views on Tesla and Musk were refreshingly nuanced given the popularity of hating on him, and their understanding ICE is at best a niche toy now and mainstream transport must be electrified.

I actually rekon this is a more common view of Musk (contrary to what the media seem to portray). I was more coming at it from the angle of them saying the ICE is still superior driving experience. Imo it's an inaccurate statement given ICE cars have had almost a century of development. Technologically EV cars are superior to ICE in every possible way. Better packaging = better dynamics, better response no need for intermediate parts like diffs and driveshafts etc. They touched on it saying when batteries get lighter it will start to improve, but was puzzled as to why despite this they still thought the future of hypercars was ICE.

 

[PJO]

thought the future of hypercars was ICE.

At the moment the energy density of the fuel powering an ICE car is about 50-100 times greater than lithium ion batteries (depending on the chemistry).
We still have a long way to go to close that difference.

 

[Stredda]

I actually rekon this is a more common view of Musk (contrary to what the media seem to portray). I was more coming at it from the angle of them saying the ICE is still superior driving experience. Imo it's an inaccurate statement given ICE cars have had almost a century of development. Technologically EV cars are superior to ICE in every possible way. Better packaging = better dynamics, better response no need for intermediate parts like diffs and driveshafts etc. They touched on it saying when batteries get lighter it will start to improve, but was puzzled as to why despite this they still thought the future of hypercars was ICE.

Well, they did say that the Supercars have a better driving experience now and they did admit that in the future this will change.
I do agree that EVs open things up to have better packaging but they all still have driveshafts and differentials unless they are running hub motors and no production car does that.
Also, you have to look at the type of person that buys a hypercar. It's not someone that wants an efficient, quiet, car. It has to literally scream "look at me" and that's a fair part of the attraction.

 

[beeb]

At the moment the energy density of the fuel powering an ICE car is about 50-100 times greater than lithium ion batteries (depending on the chemistry).
We still have a long way to go to close that difference.

But with 40-50% of that energy lost to heat, and a chunk more to driveline losses - it's not as big a difference as it seems. It's still a big gap, but not that big.

 

[Dales Cannon]

Around 30% of energy in the fuel can be converted into motion with the rest lost in heat and noise. Of that 30% a 1/5 to 1/3 is friction loss. Thus for 100% energy there is about 25% work done. Better than a public servant but still not great. Even so there is still a big gap taking into account fuel density. It will get closer and get better. It wont take 100 years to develop either.