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Comment by 0xbear | Hacker News Reader

Too bad it can’t maintain that performance for any extended period of time. Battery is known to overheat if you drive it too hard.

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It uses 3 motors (2 in the back) and has a 200 kWh battery pack. The reason for such a large battery is so that they can draw more total current without overheating, theoretically twice as much as the Model S P100DL which only has two motors (1 in the back). Having more motors means you are spreading out the current/heat. The 600+ mile range is mostly a side effect of this engineering approach to performance.

Given that the Model S 85 kw battery is 1,200 lb, how on earth will this thing corner?

Like a ton of batteries.

0-60 in 2 seconds. Slalom time... 4 minutes at a top speed of 36mph.

If you look at Teslas, they have a grill in the front that sends air to a radiator that's shared by the battery cooling system and the cabin air conditioning.

For S and X and 3, it's not beefy enough to handle an extended period of time. Also, the engine has to radiate heat.

So, you're boldly predicting that Tesla, which understands basic physics well enough that their existing cars accelerate well and don't burst into flames because of heat issues, is going to be unable to do any better cooling the battery and motors of a future car?

Making snap engineering conclusions about technology that had tens of thousands hours R&D poured into them is a popular genre of fiction.

I just see how the thinking goes. "No way this issue that crossed my mind in the first 40 seconds I heard about the product was addressed by the bunch of hacks behind it".

So, you're boldly predicting that Tesla is going to overdesign their cooling system to meet the unrealistic demand of unlimited-duration maximum power draw (in a supercar!).

I'm not saying either of you are wrong. I'm saying either of you know equally little about the engineers' decisions, and are making equally unreasonable demands.

No, I'm not predicting that, boldly or not.

Could the make the whole rear a cooling system as you described, with radiators in aerodynamic flow.

Also guessing that a 300k P4-AWDD will be announced at some point.

I’m no Tesla defender, but how is anything “known” about a car that was first announced a couple of hours ago?

It’s physics, there’s no way around it. You expend a ton of energy——battery heats up. Without massive radiators there’s nowhere for that heat to go.

You get voted down by people who just want to believe stuff, physics be damned. Doesn't matter that the same exact thing happens to the existing S models which manage a more than decent 0-to-60 performance on paper (they're in the same league with the Lambos and the Ferraris), but because of those damned physics I don't think that any of them actually completed a Nurburgring lap (that's ~7 km driving the S model like a sports car).

Really? Are you saying 7 mins of hard driving will render it literally unable to continue?

https://insideevs.com/expected-tesla-model-s-fails-lap-nurbu.... Not “unable to continue” perhaps, but unable to deliver a sports car-like performance.

The S will go into reduced power mode after 7 minutes of track grade driving: https://jalopnik.com/heres-what-a-tesla-model-s-can-do-aroun...

It’s not a track car...what do people expect?

Perhaps getting down downvoted by people who expect Tesla may have thought about this. I remember reading the overheating was due to the regenerative braking trying to push power back into the battery so it was getting hard charged and discharged constantly and you couldn't switch off the charging. The bigger battery may be so you can switch off the regenerative braking.

No, it's incorrect, physics does not mandate that battery should heat up as you expend energy. Ideally all the energy would go into kinetic energy and be dissipated by friction losses due to air or contact between the road and the tires. The battery heats up only because the process of tranferring the chemical energy from the batteries to the car motion is imperfect, and there are internal losses do to the internal resistance of the battery.

I'm not saying that Tesla has invented a sufficiently efficient battery, but to vaguely claim "physics" makes it impossible is wrong.

It does. It will heat up. To quote a physics textbook: “Power transfer between a voltage source and an external load is at its most efficient when the resistance of the load matches the internal resistance of the voltage source.” IOW in the configuration where the power transfer is at its most efficient, battery has to dissipate as much thermal energy as motor(s) are consuming. Too much internal resistance and most of the thermal energy ends up in the battery. Too little, and your motors aren’t going to do their best. But in either case even with the load that’s not 100% matched, you do end up with a ton of heat dissipation in the battery when a heavy car like this is driven hard.

That sentence from the textbook is poorly worded, see https://en.wikipedia.org/wiki/Maximum_power_transfer_theorem...

Yes, power is lower when efficiency is greater all other things equal, but you work around that by not making all other things equal.

I think he's referring to the fact that Model S's are known to overheat and go into limp mode when pushed hard at the track.

Not necessarily applicable to this particular vehicle.

If anything, it’s going to be even more applicable. I don’t see much in the way of air intakes. No intakes——epic fail on the track.

The Porsche Mission-E will handle continuous top-speed just fine without overheating, so I figure Tesla will come up with a competitive cooling solution until 2020 as well.

Porsche has hundreds of millions of dollars of R&D poured into the 919 hybrid Le Mans Prototype, which I imagine will translate to the Mission E. Tesla has no such experience.

yet.

I await Tesla's foray into serious racing with bated breath. I'm sure Porsche and Audi are terrified.

If they gave a shit about developing actual performance EVs, I'd expect them to be in Formula E, but they're not. BMW, Audi, Mercedes and Porsche are.

Perhaps they're focusing on other things? Motorsport has always been about advertising, maybe they don't see an advantage in that at this time.

Yeah, it could drive more people to want to purchase Tesla cars but since they have production bottlenecks it's not the best of times to do so.

Too bad almost no-one watches the E series, because they're boring af (and the whiny sounds are cringy). Porsche did the translation to Mission E because its parent company is called VW, i.e. a company that should have paid damages worth tens of billions of euros because its diesel engines have killed and worsened the health of tens of thousands of people all over Europe, but because VW is a German "national treasure" nothing of that really happened.

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