Porsche Taycan

Breaking news, useful data or technical highlights or vehicles that are not meant to race. You can post commercial vehicle news or developments here.
Please post topics on racing variants in "other racing categories".
User avatar
P.S.
5
Joined: 23 Oct 2011, 17:09
Location: Germany

Re: Porsche Taycan

Post

Cold Fussion wrote:
22 Sep 2019, 06:25
Why is cooling an EV so difficult given how efficient the drivetrain is? Do the batteries require some very narrow temperature range that also happens to be very low?
In a Model S the battery is not the bottleneck when fast driving, its the motor. And as we can see, with the "Plait" they have something in their pipeline.

Basically an electric Motor is very compact in its size, so its hard to remove the heat, even it is indeed very efficient.
To give an extreme example: There are actuall electric Motors available where you can pull 20 kw/kg out of it, operating in its peak efficient area. But then even with 97% efficiency you need to remove 600 W heat per kg motor. Same for regenerating.

Lithium batteries are ion conductors. So basically every plus 10 degrees (Kelvin) the internal resistance halves. Until it catches fire. That is why you have to tell your Tesla you wanna execute ludicrous mode. It then will heat up the battery so it can provide the power without damaging.

User avatar
hollus
Moderator
Joined: 29 Mar 2009, 01:21
Location: Copenhagen, Denmark

Re: Porsche Taycan

Post

You probably mean "cool" in that last sentence?
Rivals, not enemies.

User avatar
P.S.
5
Joined: 23 Oct 2011, 17:09
Location: Germany

Re: Porsche Taycan

Post

No. But sure it seems odd. If the battery is to cold and the internal resistance is high, the ludicrous mode is a bit like a short circuit for the batterie.
In that case the current flow is not homogen inside the batterie, - little hotspods (molecular size) appear where the current is going even quicker, - until it becomes that hot, tiny little areas inside the batteries get distroyed.

I got told this context without being into the industry myself, so I would appreciate if someone can confirm my words.

Tommy Cookers
Tommy Cookers
621
Joined: 17 Feb 2012, 16:55

Re: Porsche Taycan

Post

P.S. wrote:
22 Sep 2019, 12:06
In a Model S the battery is not the bottleneck when fast driving, its the motor.
.... There are actuall electric Motors available where you can pull 20 kw/kg out of it, operating in its peak efficient area. But then even with 97% efficiency you need to remove 600 W heat per kg motor. Same for regenerating.
how is 600 W/kg a problem with liquid cooling ?
though the drive aka controller is also less than 100% efficient

btw
someone wrote that the Taycan has 2 gears
how does this compare with the Tesla that people are comparing with it ?

User avatar
P.S.
5
Joined: 23 Oct 2011, 17:09
Location: Germany

Re: Porsche Taycan

Post

Its not a problem, it can be solved as the Taycan shows ;)

User avatar
P.S.
5
Joined: 23 Oct 2011, 17:09
Location: Germany

Re: Porsche Taycan

Post

Tommy Cookers wrote:
22 Sep 2019, 13:01
... Taycan has 2 gears
how does this compare with the Tesla that people are comparing with it ?
Maybe this answer your question?
https://www.youtube.com/watch?v=wDEj1dbKKlU

User avatar
RZS10
359
Joined: 07 Dec 2013, 01:23

Re: Porsche Taycan

Post