SaratogaLefty

Most likely the temperature has been warm to hot during the time from July to present. I have no idea of the SOC but I have sent a request to a number of European owners who have had their cars since May/June and asked them what distance they see on their cars immediately after a full charge. I'm assuming (maybe incorrectly) that when I get to the Dealer before accepting the car I can see what the distance shows for the fully charged battery and if that is about the same as the European guys are seeing then hopefully the battery is okay???

tgavem

Interesting read.

I have been fascinated with Rimac but they too are just try to manage how stored energy (battery or gasoline) is transferred to acceleration and motion.

http://www.rimac-automobili.com/en/t...battery-packs/

gnochi

Electromigration is technically part of the damage mechanic inside the anode and cathode of a lithium cell, but it's almost negligible relative to things like SEI (solid-electrolyte interphase) formation, which are well beyond the scope of this discussion. It boils down to the more you use the battery, the more it degrades. That is a problem, yes, but a pack with half its life, while less than optimal for an EV, is certainly usable for grid storage etc.

The millennials bit is more applicable, but even then, more and more businesses, apartment complexes, parking garages, even street parking areas are adding chargers. It does require an infrastructure shift, but it's one that's very much happening and has a lot of support.

I'm guessing the battery was sitting at about 30% SOC when they shipped it - typical for LiIon - in which case it should be good to sit for at least 6-8 months with negligible degradation, especially with the weather in SoCal over the last few months - at the hottest, we were just getting to the upper end of LiIon comfort range, and at the coldest, we were still a ways away from the bottom of said comfort range.

Unfortunately the range measurement is what we like to call a SWAG - a scientific wild *** guess - and until your battery has been fully cycled a few times it's going to be flat-out wrong at best. What you can note in the short term that'd be useful is, basically, if it's delivered below 1% SOC, it's dead, below 3%, it may be measurably degraded, and below 5%, it might not be happy but you won't notice any degradation. Keep in contact with the dealer and read through the powertrain warranty (and battery warranty, if separate) terms before accepting delivery and make sure that pack problems are covered for at least the first 30k miles and 3 years. Porsche probably includes some on-board diagnostics - I don't recommend doing an AC impedance sweep yourself, as getting access for that will void the warranty, but they probably do something similar and make it pretty obvious if something is wrong.

Glad you enjoyed it! Rimac and Romeo both make pretty good battery packs from what I can tell, and for some OEMs it's worth it to go to an outside vendor if they don't have the tech team in-house - GM basically had LG design the entire Bolt. That said, if you don't have an in-house team that can quickly adapt to the changes in usage, develop over-the-air charge parameter adjustment, etc., I think you're going to have expensive challenges to overcome as vehicles go up in mileage. The only used EV on the market right now that I would ever consider buying would be a Tesla; they're bringing their A game to this issue (if not to Model 3 manufacturing).

Airbag997

I am referring to electromigration in the control and regulation portion of the system. Not the storage elements. It's a significant issue. Analogous to the unexpected quantum effects they are experiencing at 7 nm process technology right now. We are starting to hit some very real "brickwalls" in electrical engineering.

ace37

As a mechanical (aircraft structures) engineer my though on what you’ve laid out so far is just that those will be costs - high fail rates just means design redundancies and maintainence (= periodic component replacement) are required to ensure overall system reliability. Since that’s my thought and you seem convinced your point was missed, perhaps your arguments haven’t been clearly/fully presented. You have an adequately technical group here to flesh your argument out more thoroughly if you can scrub any heavily specialized jargon.

The bar isn’t that high - ICEs and cars in general will typically fail at ~3000-6000 hours of use yet that’s the gold standard.

Airbag997

I'm assuming 3k and 6k hours is a typo for MTTF. Commercial alone has 100k MTTF requirements wrt REL. Automotive is slightly higher at ~120k+.

SaratogaLefty

I'm guessing the battery was sitting at about 30% SOC when they shipped it - typical for LiIon - in which case it should be good to sit for at least 6-8 months with negligible degradation, especially with the weather in SoCal over the last few months - at the hottest, we were just getting to the upper end of LiIon comfort range, and at the coldest, we were still a ways away from the bottom of said comfort range.

Unfortunately the range measurement is what we like to call a SWAG - a scientific wild *** guess - and until your battery has been fully cycled a few times it's going to be flat-out wrong at best. What you can note in the short term that'd be useful is, basically, if it's delivered below 1% SOC, it's dead, below 3%, it may be measurably degraded, and below 5%, it might not be happy but you won't notice any degradation. Keep in contact with the dealer and read through the powertrain warranty (and battery warranty, if separate) terms before accepting delivery and make sure that pack problems are covered for at least the first 30k miles and 3 years. Porsche probably includes some on-board diagnostics - I don't recommend doing an AC impedance sweep yourself, as getting access for that will void the warranty, but they probably do something similar and make it pretty obvious if something is wrong.

Well that makes me feel somewhat better. I will ask my dealer to immediately check the status of the battery upon receipt of the car before they hook up any charging. I will also ask if there is some kind of diagnostic they can run and print out for me regarding the battery condition. I will do some research on the warranty terms and conditions. I have heard back from the British owners who have had their cars since late May and they say their cars typically show between 23-27 mile range immediately after a full charge. Their driving technique then takes over for what they actually get but one of them did indicate that traveling a flat road at a constant 50 mph did yield 30 miles on a full charge. I really want to get this car and appreciate your helpful information.

ace37

Not a typo, but perhaps the nomenclature of an unfamiliar industry (essentially jargon so sorry if that's the case). In aircraft we use flight hours at a specific duty cycle as our basis for estimation of failures. At 40 mph average, 3000 hours is 120k miles on a car and 6000 hours is 240k. Depending on which brand of high volume and mainstream ICE powered auto you buy, that range seems to do a reasonable job of encompassing the expected service life.

The point is, it's not that long of a life, that expensive of a thing, or that big of a deal if a car fails to start or run (in a non-safety-critical failure) so the standards on what's acceptable with regard to cars not working properly are pretty modest. If a car doesn't start you might call in to work and then figure it out, that's all.

From an engineering perspective, solving battery degradation is really easy if you do it the sloppy way - just throw extra capacity at it and it will work well enough. That's how they handle SSDs, isn't it? Yeah, it will degrade as it ages, but just underrate the thing a bit, maybe use the ECU controls to lock out the excess capacity so the consumer doesn't feel it, and the product will work well enough and long enough to meet the practical needs and goals it was designed for. Now that's certainly not elegant, but it is a workable solution and it only took a moment to come up with...

If the issue is with one or more of the controls systems degrading and it can't be handled that way, well, you could design it with more than one system (backup) and require a swap either when one fails or after XX miles. They've done worse and intentionally required engine-out clutch and spark plug services on cars in the past so it's really not too unthinkable. And with computer hardware the costs may even drop after five or ten years.

gnochi

Glad to help!

The EV companies I've worked at tend to be concerned with miles and calendar years, but a few of us have worked in other industries and the hours in service matter more. (Cars tend to be limited by both, since simply being outside is a lot of wear and tear on systems.)

There are also a lot of tricks we pull to reduce the duty cycle of the electronics further, so even in full-time stationary applications the cell life will almost always be the limiting factor.

928 GT R

Tesla missed its earnings and the stock took a tumble today. They blamed unspecific problems with suppliers to the battery division for the failure to scale up production of the 3. Not many specifics were disclosed, but the problem is early in the process so it could be raw material availability or automated process issues...

Instead of building 5,000 cars per week they are only producing 120 or so with burst capacity to build 300 per week. Yikes, it's a huge shortfall in production.

Most people know that Elon Musk has a habit of over-promising, but this is a huge issue for investors and buyers waiting for their cars. How many customers will cancel their orders?

The Tesla situation is a great litmus test for how dedicated the EV buyers are. If they do not cancel their orders and agree to wait for production to catch up with promises, it will show real dedication in the population of EV buyers. If they start cancelling their orders and asking for their deposits to be returned, it will be an indicator that the demand for EV's is not so strong.

Having driven the P100S my bet is on the buyers keeping their orders in and waiting tor their cars to be delivered.

Where will Porsche source their batteries, motors and control systems and how reliable will those sources be when the Mission E goes into production?

Lorenfb

Tesla has a more basic problem than what's indicated above, i.e. it can't profitably
sell the Model 3 at the $35K price most hold reservations for. Furthermore, the Model 3
will cannibalize sales of the higher priced Model S at the projected actual Model 3 price
of $45K to $55K, and thereby continue to reduce their gross profit per vehicle as was
revealed in the Q3 report.

caf

Well, just as I don't expect to buy a Porsche at anywhere near base price, I don't think Tesla expects to sell Model 3s at base price. You can't even order a base model at present. Remember, Musk initially touted what is now the Model S as selling for $50K. And certainly it's intended to be a volume car. I think Musk truly wants to get a gob of EVs on the road; I don't think he's expecting Porsche level profit margins on the 3.

Cannibalization is certainly a risk, but many of those who originally came through the door to buy a Model 3 have ended up buying Model Ss, so there's some upselling going on as well.

Though I own Tesla stock for the long term I've been telling everyone that would listen that there would be lots of share price turbulence as Tesla tried to launch the Model 3. The production ramp up was more likely to have glitches than not. In the long term they'll be fine; it just may take an additional couple of months to get the the production line humming. They've got plenty of demand to drive sales for the foreseeable future even is some of the waiters get restless.

One thing for sure: unless you're blind to progress, once you've driven a nice EV the writing is on the wall. We'll all be driving EVs. It's just a matter of when, not if.

daveo4porsche

+1 CAF

I’ve done over 150,000 mile with EV’s since 2012 - once you go Elric there is no going back!

I have two gas cars both Porsche’s - they are recreational vehicles
15 Boxster S for the wife - she loves convertibles
GT3 for my track car

The electric cars handle all of our daily commute and errand needs - wife loves skipping the gas stations - I love the lack of any maintance other than tires.

I look forward to moving them to electric in the future

Once you get used to instant torque gas cars seem so slow.

caf

Agree, dave04,

I think at some point in the not so distant future, our gas-engined Porsches will be hobbyist cars. We'll certainly enjoy them for a fun weekend drive or on the track, but for day to day use electric is the answer.

Lorenfb

Poor analogy.

But the majority of reservation holders do expect that.


So what, at the expense of the shareholders and government?
Intentions and long term reality don't always intersect.


Yes, many of us now have BEVs, but realize their present shortcomings, i.e. battery degradation
& charging times.