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Old 04-21-2017, 09:50 AM
  #31  
RealityGT
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Can't wait for mine! Been waiting over 2 years already.. haha
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Old 04-24-2017, 01:08 PM
  #32  
DoninDen
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Originally Posted by RealityGT View Post
Can't wait for mine! Been waiting over 2 years already.. haha

Any concern on it being 1st Gen? I have my name on a list, dealer is not taking deposits yet. I'm not sure how I feel about a electric Porsche. I mean it should clearly take off from where Tesla is for performance, but what will it be?
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Old 04-24-2017, 02:05 PM
  #33  
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Originally Posted by DoninDen View Post
Any concern on it being 1st Gen? I have my name on a list, dealer is not taking deposits yet. I'm not sure how I feel about a electric Porsche. I mean it should clearly take off from where Tesla is for performance, but what will it be?
I would expect first model year issues, but Porsche has a fairly accountable track record.. and I'm good with my dealer.. so I don't foresee any major headaches.
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Old 04-29-2017, 11:39 AM
  #34  
Charlie C
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Originally Posted by DoninDen View Post
You are correct with this question, as part of the significance of the car within the lineage of the 911, is the e will mark a reversal and a return to the air cooled 911 after a 20 year hiatus.

At the same time it will incorporate the technological advancements of the the past 20 years into the new generation of air cooled e 911s, most importantly being the Sound Symposer.
I think they should include a small V-8, you know, just for that deep engine sound.
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Old 10-03-2017, 09:43 AM
  #35  
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Originally Posted by Charlie C View Post
I think they should include a small V-8, you know, just for that deep engine sound.
a 15k Burmester optional audio system programmed with 24 speakers pumping out Porsche 911 GT3 cup car engine sounds should do the trick...
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Old 10-05-2017, 06:55 PM
  #36  
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Originally Posted by DannieK View Post
I'm most concerned with one of its more controversial aspects: charging to 80% in 15 minutes at 800 volts. I read something somewhere about the unliklihood of finding a charger with that capacity. I wonder how much it'll cost for my garage and what would be its other electrical requirements?
.
Since American homes have 240 running into them, we're not going to get those kinds of charging times - maybe at electric stations/charge points.

still 80% charge in 45 minutes at 240 volts isn't bad.

The Tesla superchargers put out around 300-400 volts - so 30 minutes roughly to 80% charge. Whether the ME can use that is another issue.
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Old 10-06-2017, 10:40 PM
  #37  
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charging math

watts = Volts * AMP's

240 volts * 30 AMP = 7,200 watts or 7.2 kiloWatts

do this for 1 hour - and you get 7.2 kilo-WATT hours

most American homes have 100/200 AMP service - which means the maximum watts they could sustain is 24,000 or 48,000 watts

but you have to de-rate that by 20% since you can't pull that high of a load on a circuit - so you can get 80% of that load

100 amps * 240 volts = 24,000 watts
24,000 watts * 80% = 19,200 watts

which by the way is the current specification limit of a J-1772 charging connector (the pre-dominant connector in use in North America)

Tesla Model S/X come with 72 AMP chargers in the car for AC charging (that is a 90 amp circuit installed in your home).

Porsche as stated the car will go at least 300 miles…

the physics of the situation for moving 4000-5000 pounds worth of car is best case your going to get 3 or 4 miles per kWh of Battery capacity - let's give Porsche the benefit of the doubt and say they are going to get 4 miles/kWh

that is a 330 miles / 4 = 85 kWh batter (just like the original Tesla's)

85 kWh battery / 19.2 kW = 4.42 hours to charge the car best case but you have to add 10-15% for charging loss so let's call it 5 1/2 hour to charge the car from empty to full

to fill 85 kWh in 15 minutes means you have to deliver 340,000 watts - 1/4 hour of that would be 85 kWh - the current standard for fast charging is proposed 350,000 watts - so that makes sense

340,000 watts / 800 volts = 425 amps - I'll call that doable

Home charging @ 240 volts = 5 1/2 hour full charge on a 90 amp circuit
Home charging @ 240 volts = 12 hours full charge on a 50 amp circuit

Roadtrip charging at a fast DC charger with 800 volts @ 400 amps = 15 minutes for 85,000 watts

Tesla Superchargers are 400 volts/400 amps - 160,000 watts

but that's not the whole story - LiON batteries can only be stuffed at that rate when they are close to empty - as they get closer to full you have to taper the current to avoid damaging and overflowing the batteries - so while you start at at max watts you only get that for like 0 - 10% capacity then it starts to taper

having driving to thunderhilll numerous times in my Tesla Model S and stopping at the supercharger in Vacaville the charge rate often starts at like 320 amps (I"m never close to zero) and 40 minutes later when the battery is at 80% charge it has tapered to 80 amps (or about 32,000 watts)

the last 20% of charge takes as long as the first 80%

I see no reason to expect Porsche to overcome this chemical limitation of LiON batteries.

when dealing with large capacity batteries and wanting charge times to drop - you have to figure out how you're going to deliver that many kilo-watt-HOURS in less than 15 minutes -

if you want 100 kiloWATT hours in 10 minutes - you need a 600,000 watt source - then you need to work the Volts/AMP's math to see how that works.

240 volts and a maximum of 200 amps (really 80) - in the average home is never going to provide 100 kiloWatt hours in less than 5-6 hours…
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Old 10-06-2017, 10:53 PM
  #38  
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by the way - you can charge at most any RV Hookup you find - and strangely enough there are RV hook ups at most tracks we visit - I've been charging my Tesla at Thunderhill for the past 4 years using their ample RV hooks - typically RV hooks up are NEMA 14-50 plugs

this 240 volts @ 50 amps - derated by 20% means you get 9,600 watts - or 9.6 kW - charge for 1 hour = 9.6 kWh

charging time there for is:

(battery_capacity_to_charge / 9.6) * 1.15 = hours

example

(42 kWh / 9.6 kW) * 1.15 = 5.031 hours if pull into Thunderhill with your Tesla Model S P85D at 50%'ish battery…

the average public charger you encounter in the US is 208 volts @ 30 amps - just about 6,000 watts

there are 3 (soon to be 4) fast charging standards

1. Chademo - Nissan Leaf - 400 volts / 150 amps - 60,000 watts
2. SAECombo/DCFast - 400 volts / 150 amps - 60,000 watts
3. Tesla Superchargers - 400 volts / 400 amps - 160,000 watts
4. Porsche fast chargers 800 volts / 400 amps - 320,000 watts (reasonable speculation)

all of these DCFast chargers bypass the onboard car charger and shove DC current directly into the battery…

also not all chargers are created equal - some DCFast chargers from Chargepoint are only 24,000 watts which charge much slower than the 60,000 watt versions from eVgo…

nearly all cars currently manufactures are down to 30,000 or less watts by the time they are 80-90% full - meaning it will take another 20-30 minutes to fully top off the battery - savye EV owners known this and abandon charging to drive to the next fast charger if they are road tripping - you space the fast chargers on major road ways to fit the 60-70% percent range of the car since that's the sweet spot for charging duration.
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Old 10-10-2017, 05:32 PM
  #39  
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apparently my math was spot on…

http://www.hybridcars.com/porsche-sh...turbo-charging

"Porsche’s Turbo Charging technology. It’s an accumulator-based fast charge system that can charge at 800 volts and up to 320 kilowatts for a single vehicle, or 160-kW for two cars. That’s close to three times the 120-kW charge that a Tesla Supercharger can deliver."

Tesla Superchargers are 350,000 watt chargers split two ways - but a single car is limited to 160,000 watts and can never get the full 350,000 watts - the article is almost correct

again if Porsche is using standard LiON batteries you will need to be nearly empty to get that rate of charge and it will quickly taper into the 80,000-120,000 watt range…still respectable.
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Old 10-10-2017, 05:39 PM
  #40  
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but this does mean if there are two cars charging - 80% charge capacity will take 1/2 hour not 15 minutes - which means it's about the same rate as Tesla's supercharger unless you happen to have the charger all to yourself…
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Old 10-10-2017, 05:40 PM
  #41  
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if Porsche were to offer a Tesla Supercharger adapter - that would be awesome - and I'd plunk down money today!
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Old 10-15-2017, 09:41 PM
  #42  
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Personally, I'll be holding out for a GTS trim.
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