chuck911

Chalk this up to cognitive dissonance. The automobile is all about freedom. Porsche one-ups that, raising the bar to actually enjoying the act of driving. The idea of slogging back and forth to work, Porsche actually has videos showing how boring that is. So its all about the freedom. But, the two places we most enjoy this freedom are the track and remote country roads. The track kills EV's in minutes, and country roads, EV's can't even get to most of them. But EV's are still cars, which are sold on the dream. So cognitive dissonance: the least free car must nevertheless somehow appear to bring freedom. When people can't stand the truth they fall back on repeating the lie. Its not obsession. Its a form of mental survival. Why they just don't change their minds in respect of reality, that is the question.

unclewill

Be that as it may, the collective push to transform EVs into track cars and long distance cruisers is leading to great leaps forward in updating our infrastructure to accommodate these uses. If the track has an 800V charger, the Mission E owner will need only 15 minutes for a full recharge - according to Porsche anyway.
God bless the person who enjoys the act of driving while sitting in the rain on a gridlocked freeway on a Tuesday morning at 7:55 AM...

daveo4porsche

full in 20 min is not quite what Porsche has said:

https://electrek.co/2018/01/23/porsc...ng-technology/
“We intend to revolutionise charging times by doubling the capacity of the high-voltage system from 400 V to 800 V. In a nutshell – a range of 400 km in less than 20 minutes. Without exception, all our current competitors are advertising charging durations which are twice as long.”

fast charging requires that you tapper the charge (typically by lowering the amperage) as the battery approaches "full" - it's an exponential type thing - typically you can get from about 5% charge rate to 80% charge rate in 20-30 min - then from 80% to 100% takes another 20-30 minutes - the batteries charge at the fastest rate when they are close to empty - but charge quite a bit slower once they approach 70-80% capacity - it effectively takes twice as long to get to 100% charge as it does to get to about 75% charge rate…and porsche has no magic here AFAIK - it's a characteristic of the LiON charging process and not subject to competitive advantages ;-)

when traveling long distances with an EV - you typically do not worry about "full" - rather you stay at a fast charger only long enough to get enough range (+buffer) to the next fast charger or your destination - and while traveling you only do a full charge over night at your destination…if you insist on being FULL everytime you leave a fast charger you will dramatically increase your charging time and hence your travel time...

when I road trip with the Model S I typically charge for 20-40 minutes, and leave when I have a comfortable buffer for the next segment of my trip - I did do a full charge from 3% to 100% once at an empty Tesla supercharger late at night and it took over 110 minutes to reach an absolute 100% charge rate - the last 15% of charge rate occupied 20 minutes of the total charge time, or about 8.5 kWh of power, or about 28 miles of range…once most LiON batteries are above 90% SOC you've tapered the charge rate to less than 10,000 watts or even 7,000 watts (which is less than a 40 amp home 240 volt circuit)…

no doubt having fast chargers available at tracks would be useful - and help for a track day - but if a driver kept "topping" off after a session from about 60-80% they wouldn't be getting as much value as charging from like 20-70% in about the same amount of time at "the pump"…

Tesla documents the exponential characteristic of their superchargers on their website here - https://www.tesla.com/supercharger - with them showing a typically 80% charge taking 30 minutes, but a full charge taking nearly 90 minutes…

I have no data to indicate that Porsche's charging system will be linear - and therefore expect them to suffer the same need to taper charge rates as the battery approaches full - this why their statements are carefully worded to discuss "range in X minutes" rather than "full in X minutes" - but even that is non specific - because if you pull in with your Mission E battery at nearly 70% charge capacity - there is no way you're getting 400 km in less than 20 minutes - in fact you'd be luck to get 100 km in less than 20 minutes at 70% SOC…the ONLY way fast charging delivers that sort of performance is if the battery is nearly empty.

the good news here is that since over 98% of miles of driven fit into less than 90 miles range in a single day - the number of times anyone really uses fast charging is very very low - and I personally find the trade off of the occasional road trip taking longer due to fast charging to be acceptable vs. the daily convenience of charging to full over night.

unclewill

According to Verena Mei in the latest Adam Levine vid it's 80% in 15 min...OK you got me.

Wanna have some fun? Check the price of lightly used Fiat 500es. Ya think the value of the Mission E will plummet like a lead balloon too?

daveo4porsche

it wasn't so much of a "gotcha" moment and it was a nuance - the whole fast charing thing is a bit of head-fake from the whole EV industry - it doesn't quite work the way people expect - it's pretty functional but not ideal and has vast room for improvement - apologies if you feel I was calling you out - that wasn't my intention - it was more an attempt to use the posting as a "teaching moment"

I look forward to future battery chemistry that have linear charging rates (i.e. you can pump electrons in the the battery at a continuous/constant/unchanging rate) - given that I"m not a chemical engineer nor an electrical engineer I"m not sure if it's possible…but certainly desirable.

the good news is that batteries should be sufficiently modular that if manufactures wanted to they could swap one type of battery for another and keep the rest of the car intact with virtually no design changes - so it should be possible to improve EV batteries if the battery tech suddenly becomes better.

daveo4porsche

@unclewill - one more time - apologies - not specially targeting you with my posting - just point out that fast charging isn't quite what people think it is.

daveo4porsche

here are some charging curves of time vs. range for a Tesla Supercharger - Porsche's slope should be steeper (with 800 volts) but it will eventually have to ramp down the charge rate (just like Tesla) as the battery gets closer to full

https://speakev.com/threads/tesla-su...5d-xp85d.8538/

unclewill

No big deal brother, I just think that with the proper charger, the die hard who must take the Mission E to a track day will be able to do it. Seems to be what Porsche is shooting for eh? Not exactly a practical consideration but I'm sure we will all benefit!

1crazy canuck

Porsche should push super hard to get a deal with Elon on use of the Supercharger network -- it is a BIG differentiator, and opens up the Taycan to becoming more than just a city / around town car.

Tesla is likely not that motivated now though - as they have a pretty big moat separating their product from everyone else with the Supercharging network.

I would LOVE to see the Taycan succeed - but I know they need to either get on the Tesla Supercharger network - or build out their own (not likely)

txhokie4life

As I understand it, you don't want to ever overcharge any one cell as it will damage that cell. As one climbs too high, you have to level out across all the batteries, than begin
to charge across the board -- rinse and repeat.

So I think that is why you can go from 20-70% very quickly, and going from 70-100 takes so much more time.

I could imagine a competitive advantage if you could limit the single cell overcharge or imbalance somehow, and/or level it quicker.

I'm not saying that is possible or that is what is being attempted -- but conceptually -- this is how one vender might be able to do this differently.

It might also be the 800v configuration allows for some advantage in this overshoot prevention and top off process.

Shanh81

unclewill

Check with your regional electric utility there is a huge EV charging network being built nationwide right now - as long as Porsche uses industry standard charger connections.

Porsche will never be on the Tesla network.

ChicagoWhale

Shanh81

Sonnen Porsche

Porsche/VW have already started their network with the dealers needing to install 350KW /800 volt fast chargers and Electrify America are taking care of the majority of the country with their network which should be running when this new car arrives :

https://www.electrifyamerica.com/our-plan


Electrify America will establish a comprehensive, technologically advanced, and customer-friendly charging network -- to drive EV adoption by reducing charging anxiety.

In its first ZEV investment cycle, Electrify America will establish a network that includes non-proprietary electric vehicle chargers (CCS, CHAdeMO and J1772 standards) at over 650 community-based sites and nearly 300 highway sites across the country.

• After a methodical and data driven analysis taking nearly six months, Electrify America selected seventeen metro areas including Boston, Chicago, Denver, Fresno, Houston, Los Angeles, Miami, New York City, Philadelphia, Portland, Raleigh, Sacramento, San Diego, San Francisco, San Jose, Seattle, and Washington, D.C.
• Community-based charging station sites will be built in workplaces, retail (shopping centers, restaurants, etc.), multifamily residential locations and municipal lots and garages, as well as high-speed community depots that will feature fast EV charging at speeds of up 150kW compared with today’s peak of 50kW.
• Highway sites will be located along high-traffic corridors between metropolitan areas, including two cross-country routes, and will include between four and ten 150kW and 350kW individual DC fast chargers at each location before June 2019.
• These sites will be located no more than ~120 miles apart and on average just 70 miles apart. Many shorter range EVs will benefit from 50kW DC fast charging on the Electrify America highway network, including any CHAdeMO equipped vehicles.

https://arstechnica.com/cars/2018/04...e-end-of-2019/


Hopefully this company can get the chargers up and running before these cars roll into dealerships late next year....

Other companies are also expanding their charging network and are now installing the higher voltage chargers as well.

https://na.chargepoint.com/charge_point

Looking forward to seeing the production version of this car!