No Limits on Supercharge Cycles!

No Limits on Supercharge Cycles!

Talked with Supercharger chief engineer tonight at event and definitively confirmed:

1. You can Supercharge as often as you like with NO degradation of battery.

2. TM software manages everything. You just hook up.

3. Charges to 50% at high rate, then tapers. After 80%, it slows more to protect it (but keeps charging)

4. Optimal use is fast (30min) charge from near empty.

The technology and the business model are game changers for EVs.

When you go 1,000 miles on sunlight for free, why would you spend $200 burning gas?

This SuperCharger is a total win.

DouglasR | 24. september 2012

Great info, Mark! Thanks.

Timo | 24. september 2012

There will be some degradation of battery, but probably not big enough to be any significance. Great news.

Mark K | 24. september 2012

@timo - that's right, in context, this means no degradation relative to other charge sources.

All charging of any kind produces some nonzero change in battery capacity, but what's relevant here is that you need not worry about using the SuperCharger instead your home charger. You'll get similar life.

This is very important to the uptake of the SuperCharger.

TM engineers made the software smart enough to handle charge management and battery protection completely transparently to the user.

Well done team TM.

Mark K | 25. september 2012

BTW, the SuperCharger chief practices what he preaches.

Today was the start of his vacation, but he chose instead to come down to the LA event.

He drove to LA from Palo Alto in a Model S and stopped at his SuperChargers to sample the wares.

They worked like a charm.

olanmills | 25. september 2012

Yes, this is such awesome news. I think this brings EV's basically 90% there when it comes to practicality and convenience for every concern, and it certianly beats ICE in certain other categories. I think the 10% gap will be closed in the future when higher capacity batteries are available at lower prices than today.

Also, thanks for posting this confirmation Mark. I think it definitely is not surprising given that there are no warnings about using the superchargers on any of the fact pages.

Timo | 25. september 2012

Yes, this is such awesome news. I think this brings EV's basically 90% there when it comes to practicality and convenience for every concern, and it certianly beats ICE in certain other categories.

I think this brings EV's at 175% when it comes to practicality and convenience for every concern (compared to ICE cars). It would be 200% if it could be recharged at less than five minutes, and 250% if they were as cheap as ICE cars to buy. IOW I think they already exceed ICE in almost all possible ways, only remaining factor was the range concern, and this is now going away.

I hope Tesla build these superchargers at Europe too in near future, so that people buying GenIII cars can get that benefit from the start.

olanmills | 25. september 2012

Well for me, considering all of the aspects, the Model S is better than an ICE car.

That said, there are still advantages and disadvantages. And that's what I meant by saying it's 90% there.

In an ICE car, you can go from 0% fueled to 100% fueled (or more comparabley, 0 miles of range to 300+ miles of range) in a few minutes, and refueling locations are basically everywhere.

In the Model S, you can go from ~0 miles of range to 150 miles of range in 30 minutes, and despite the agressively impressive plan for supercharger installations, you will have to be way more thoughtful about your longer trips than you would in an ICE car.

I really believe that some day, Tesla cars will meet and exceed these aspects of ICE cars, and that the time frame is a matter of years, not decades and decades, but I don't think it's honest to say that range is no concern at all, because today, ICE has the lead.

Mark K | 25. september 2012

@Olanmills - That's true, it's fair to say that it's a balance. Each has its advantages.

An ICE car may do some things an EV won't do - but it'll also cost you $200 more for a weekend road trip.

What TM just did with the SuperCharger install plan and free access summarily shifts the balance.

In a world where Google maps are now on live on our dash, the downside of going where fuel is free becomes immaterial.

But the upside of $200 back in your pocket is not.

EVs just got a whole lot more attractive.

Brian H | 25. september 2012

By end of 2013, essentially parallel with the first EU deliveries, Elon said there will be stations in EU (and elsewhere). The cost to TM is apparently almost trivial, and Solar City will be 'running' the sites and benefiting from excess power 'feed-in tariffs', which ensures they will keep the stations spic-and-span (a colloquialism referring to a longstanding cleaner brand which touted itself as the ultimate household scouring product!)

prash.saka | 25. september 2012

@Mark K, this is excellent news. Thanks for sharing.

~ Prash.

Mark K | 25. september 2012

On 40KWH pack supercharging-

TM isn't holding this back for cynical marketing reasons, it's a technology-driven decision.

The engineering problem for 40Kwh packs is nontrivial with today's batteries.

There are many issues -

1. The 40KWH pack uses less expensive cells that aren't as advanced in their cell chemistry. That means you must constrain charging more to guarantee long life.

2. The circuitry and wiring to accept hundreds of Amps of DC current add parts that cost money. This doesn't allow the favorably low entry level price point.

3. Since fast charging works as a percentage of capacity, a half-size battery means only half the miles gained in a 30 min charge. Those numbers don't deliver the benefit a road tripper wants from a fast charger.

TM's engineering choices are honest and intelligent. Whenever there's an amazing deal like the free supercharging, everyone wants in. (Even those who don't pay for the equipment to do it.) Taken to logical extreme, some might ask "why don't they make the car free too?" But that's obviously unsustainable.

To do the hard work to make all this possible costs money so they have to charge a fair price to deliver them to more people. They did an honorable and smart job optimizing the benefit at each price point.

The 40KWH car is no slouch either. It's an extraordinary deal for the city commuter. Unparallled safety, ride, fuel economy, roominess and beauty. It offers all those benefits of the fancier model, but just not the road trip range.

The notion that you add in the road trip range and now free charging for 10k more is mind-blowing.

The SuperCharger strategy is a brilliant hit out of the park. Elon wasn't overstating the significance when he used the term "historic".

Sudre_ | 25. september 2012

Curious tho. If the charger can automatically lower the voltage at certain charge points. . . . why can't it charge the 40kW battery slower?

Any thoughs?

I am getting the 60kw battery so I am happy.

pilotSteve | 25. september 2012

Love the Superchargers, of course! I do wonder how much the economics that allow "free" charging may change in the future as electricity buy-back premium rates from renewable sources (Solar, Wind) go back to grid parity.

For example. California's RPS plan requires that "retail sellers of electricity shall serve 33 percent of their load with renewable energy by 2020" so maybe I'm thinking too far ahead. Nonetheless these incentives are surely the key to the Solar City/Tesla economics.

mrspaghetti | 25. september 2012

@Sudre_: They already have slower chargers for the 40kwh pack. They're called J1772.

Mark K | 25. september 2012

@tesla.mrspaghet - That's right, the differential benefit is less for the 40KWH pack since you can fill to 50% capacity relatively fast with other charge options.

Moreover, it would hurt many and help few to tie up charge bays with slow charging. One 4 hour slow charge would block 8 others who need half hour fast charges. They've got architect it to provide great service to the maximum number of people.

To build great stuff, you've got to patiently study the puzzle, and think through all the these details.

TM can't explain every technically complex, confusing detail that went into it, but the wisdom of their design choices does shine through.

scole04 | 25. september 2012

I am interested to see if Tesla will offer supercharging for those looking to upgrade for 40 Kwh battery packs in the future. Also does anyone know how long it takes on a J1772 to fill a 40, 60 & 85 Kwh in general.

murraypetera | 25. september 2012

I think Tesla would be thrilled to have the problem of 8 people waiting to charge up! This would truly be a sign of great success.

J1772 is 30 Amp or up to 80 Amp
30 Amp = 18 miles/hr
80 Amp with twin charger is prob close to 50 miles/hr

DC Quick following the 50% rule on the 85 and 60 pack would be 2 to 3 times quicker than the Twin Charger or ~ 120 miles/hr

Tesla please add this to the 40KWh battery pack!

gimp_dad | 25. september 2012

Note that the 40kWH car can't be configured with the dual chargers so will max out at 40A charge rate (on a 50A circuit). This yields 30 mi/hr in current terminology but it is probably better to talk about it as 9.6kW charge rate as the "rated range" will be changing soon to more conservative numbers such that cars will soon be reporting a lower number than 30 mi/hr when charging at the same 9.6kW energy rate.

Anyway, this 9.6kW rate should yield about 4 hours to charge from zero to 85% on a 40kWH car. Realistically that is 100 miles of range unless you are hyper-miling.

I agree with others that have said that the 40kWH car just isn't really designed for road trips. Purchasers should keep that in mind when they buy. Even if they did add support for supercharging (I don't know if this would have added cost) I assume they would have to scale the charge rate back so that it would take about an hour or more to charge to 80%. An hour for 100 realistic miles still isn't very useful.

murraypetera | 25. september 2012

"Note that the 40kWH car can't be configured with the dual chargers "

I have an order with Twin Chargers on a 40KWh battery.
I just checked the design studio and could configure this option as well.
Now If I could add on Supercharge Hardware I would be very happy.

Brian H | 25. september 2012

not happening. Way more trouble than it's worth. It can't just be "added".

cerjor | 25. september 2012

olanmills: you will have to be way more thoughtful about your longer trips than you would in an ICE car.

On road trips with my ICE I gas up at Costco. So I already have to plan ahead.

dahtye | 25. september 2012

Seems to me that to accomodate the 480V DC supercharge, the wiring to the battery will need to change. This change in battery wiring will be more expensive, hence the reason TM is including this only on the two larger battery options.

To get the faster charge, TM may have "parallelized" the batteries so they can be charged either 2x or 4x faster with DC charging. Without this additional wiring, it would not support the fast charging.

Also, with super chargers spaced about 150 miles apart, this renders using a car that has a max range of 140 miles pretty much useless on the SC network. Certainly, you might be able to use a local SC for local driving, but that would defeat the purpose of super chargers - for long distance travel.

gimp_dad | 25. september 2012

@murray I stand corrected. Is this a change? I thought I remember the twin charger option only being available on 85kWH and 60kWH configs when I was filling out my order.

Anyway, sorry for my confusion...

murraypetera | 26. september 2012

I put my order in about a month ago. I seem to think it has always been an option but am not sure.

I think contributors to the forms should be more careful about stating facts. I see a lot of concrete statements made about what Tesla's tech can and cannot do.

If you have information such as the battery tech being put into the 40KWh pack, please share it. I am sure many of us would love to read about it.

If you are guessing about a tech then wording like:

I do not think that adding DC Quick Charge to the 40KWh pack would be a significant cost or change. Since all this tech is already developed and delivered in the 85KWh pack. I would guess that the hardware cost is negligible and would only be a small software change to tell the super charger how much current to send to the car so it does not overload the smaller battery pack.

nickjhowe | 26. september 2012

@murraypetera - never seen anything in writing, but at the original launch event in Oct 2011 I spoke to an engineer in the factory who said that the 40kWh battery uses one type of cells, and the 60/85kWh batteries a different type. The difference between 60 and 85 is the number of cells in the pack. Allegedly the 40 and 85 packs are full of cells; the 60 pack is partially filled. Never had this confirmed.

dahtye | 26. september 2012

I asked about 6 months ago about the difference in the battery options and whether the 40KW battery just had fewer cells and if that would alter the weight of the car.

The TM sale rep at the Menlo Park store said the batteries have different chemistry/technology depending on which battery option is selected. She didn't answer my weight question though. But I did get the impression that the battery compartment on the 40KW battery would be full (i.e. not 40/85% full).

This is consistent with the comment by nickjhowe above. The assumption is that the differnt chemistry/technology will alter the watt/cc or charge density in the battery.

murraypetera | 26. september 2012

I also asked this question and the answers varried widely depending on who you asked. This leads me to think that they had not yet decided on any of this.

Not knowing hardly any of the variables I would think a manufacture would want as much commonality as possible between products. In this case battery packs.

That said if you are buying huge quantities of a single part, you will get a much better price than getting a mix. I would also guess that they will use the same battery they used in the Toyota pack.

So it is stil an open question which we may never know the answer to but will get an indication of when the specks for the 60 and 40 come out. Weght being an indicator.

I still think DC quick can be done with any battery tech. It is just a matter of how many eletrons you can throw at the battery without damaging it. If they are using more cells of lower power density this would make it easier than fewer cells of higher power density.

stephen.kamichik | 26. september 2012

Notice that the Model X will not have the 40 kWh battery pack. The 40 kWh pack is probably "old" battery chemistry, probably soon to be discontinued. I doubt if it could survive supercharging.

Mark K | 26. september 2012

@murrayptera - recently hired sales staff will indeed answer questions differently from senior engineering management. That's very normal. It takes time for sales staff to get briefed on technical subtleties.

To say it's not been decided conflicts with fact. TM has published the config options for a year now. Supercharging only made engineering sense with the bigger packs. It's been decided for a long time.

It is understandable why folks buying the entry level model might cajole TM to give them the free fast charge benefit. But this won't change the physics or the costs.

There's truly more copper, more silicon, and more chemistry to do the cooler thing. And they all work together in a delicate balance that is not as simple to tack on as you might think.

Brow-beating the guys who are working their hearts out to bring you fantastic new value won't be productive.

It just slows them down with distraction, sows confusion for buyers, and dulls the pleasure of enjoying what this car can really do for you.

I know that's not the reason folks keep asking,, but it's unfortunately the byproduct, and it won't get us anything.

Instead, put the intellectual energy into carefully studying the cost/benefit of 40 vs. 60.

The 40KWH costs 10K less and is the best city car you can buy, hands down.

The 60KWH goes farther and gets fast free charging, which is an amazing, game-changing deal.

Let's choose amongst what they can do, and be happy these guys took the time and care to make our excellent new choices actually possible.

Ohms.Law | 26. september 2012

+1 Mark K. Thank you.

jhuang | 26. september 2012

My understanding is that both the 60KWh and 85KWh packs have the hardware included, but what about the software? I presume the 85KWh is free hardware and software is ENABLED for free charging. What about the 60? Do we need to pay an extra option to "enable" the software for Supercharge? I asked a Tesla rep this question and he couldn't answer this question.

Does anyone know?

Mark K | 26. september 2012

@joseph - everything you need for supercharging is included in the 60KWH pack.

No enabling add-ins are needed (software or hardware).

Some confusion arose when Elon was presenting the SC and spoke about a small upgrade for the 60KWH pack, but I believe he mis-spoke. Early on, they had an "optional" spec for that, but they've since decided to include it at no extra charge.

The definitive spec is on the current "options and pricing" page, which makes clear it is explicitly included with the 60KWH pack.

At 59K after rebates, plus free solar fuel, this seems like the sweet spot for many buyers.

For me, it's the P85 because "Dammit Scotty, I need more power!"

jhuang | 26. september 2012

@Mark k, thanks for the response. I certainly hope that's the case. I am also still leaning toward the 85, biut still wondering if it'll be wiser to save the extra 10k.

mrspaghetti | 27. september 2012

I'm with Mark K - not for power, but just for maximum flexibility. On those infrequent occasions stuff comes up and I have to drive around unexpectedly, I don't ever want to find myself short on available miles. I don't want to have to devote any of my limited brainpower to planning my trips unless they are truly long distance - the kind you have to plan for to some extent even with an ICE. That's why I'm pushing the limits of my budget to get the 85kwh battery.

Brian H | 27. september 2012

The 85 also suffers less "stress" from either normal or heavy use. It has more muscle for everything.

mw | 27. september 2012

I see alot of talk here about the 85kwh vs 60kwh batteries and what is or isn't included. I am getting my S next week with 85kwh so this doesn't impact me. I am curious tho. The Option and Pricing page says up top in the battery section that supercharging hardware is included. In the charging section on the Options and Pricing page it says there is a $1500 charge for the 60kwh battery to get the on-board twin chargers? Are the twin chargers not needed for supercharging? My guess is that the twin chargers only speed up wall charging at home on the 240-100amp wall unit? Can anyone confirm?

stephen.kamichik | 27. september 2012

mw...that is correct.

Brian H | 27. september 2012

That is, the second possibility is correct (you asked about both implicitly, I think). The chargers don't figure into it at all, since DC bypasses them. They share the same plug, using different contacts, but that's it.

jbunn | 27. september 2012

Perhaps knowing why will help folks understand. All battereries are DC Direct Current. All wall current is AC Alternating Current, which switches the positive and negative poles about 50 to 60 times per second. The systems are NOT directly compatable. Plug your car into the wall, and AC is converted into DC by the onboard chargers. Having two lets you use higher wattage AC sources. The onboard chargers change (rectify) the AC into DC which the batteries can absorb. The motor in your car is variable vrequency, and a seperate power module converts battery DC into variable frequency to drive, and reverses the process to regen. Whew...

Supercharging is a direct DC to DC dump from the Tesla supercharger to the battery, and bypasses the car's AC to DC converter(s). Having the extra charger will not change your supercharging rate as they (or it) is not used at all.

Hope this helps.

Mark K | 27. september 2012

Steven, Brian, and jbunn are all correct.

A little additional color:

At the SC event I played with the cable on the charge bay kiosk. It is massive (in a good way).

The cord is only about 5 feet long, but is nearly 2 inches in diameter. (Compared with about a half inch for the standard 240VAC cable).

This is because it carries so much more current. Here are the numbers:

240VAC at 20KW is 83 amps.

480VDC AT 100KW is 208 amps.

You need 2.5X more copper cross-sectional area, and thicker dielectric (insulation) for the higher voltage. So it needs to be fat and as stubby as possible. Ergo the really big short cable.

Despite this, TM did a very good job with the industrial design, and the cable and plug handle are easy to use and feel very secure. The plug handle is actually quite beautiful, with stainless steel accents.

That power coming through the fat 208 amp cable cannot squirt through the small 83 amp cable inside the 40KWH car, much less squeeze though the 10 or even 20KW on-board chargers.

So they have to bulk up the cables inside the car, bypass the on-board chargers and fan out directly to the cells using direct current. There are definitely significant hardware costs to do this.

The chargers that do the job are actually outside the car, inside the SC monument post. (It can hold 6 chargers). That spire can pass 600KW though it's slender form. That's just shy of a megawatt, which is, uhh ... a lot of power.

The whole experience oozes a feeling of megajoules of energy, and you sort of find yourself looking around for the scintillating core of dilithium crystals.

I like this future. A lot.

Mr. Sulu, bring us home. Two to beam up.

jkirkebo | 28. september 2012

Again, the cable will not carry 480V DC. At least not while charging any know Model S. The Model S has a nominal 360V battery, which should translate to approx. 390-395V max (4,1V per cell).

Thus, to deliver 90kW, the SuperCharger must supply at least 90,000/390=230A. My guess is that it delivers 250A so the full 90kW is available at 360V battery voltage, rising to ~98kW at max battery voltage before ramping down.

Mark K | 28. september 2012

Jkirkebo - didn't get a chance to ask SC chief engineer to confirm charger output voltage, (other folks talked about that figure). The actual voltage seen at the car may be less, and can easily reconcile with your assumption due to other factors.

Chargers are at some distance from the car and the ultimate termination at cell. There are nonzero ohmic losses in between, especially at such high current when the current density in the copper conductor is nearer to saturation.

LiIon cells often get 4.2V to drive 1C or higher current input. Generally what you want is a source potential a little higher than needed (to allow margin for losses) and then PWM at high frequency to regulate the average current. This way all the FET switch channels are always operated fully saturated for lowest loss in the source electronics.

So even if the source supply starts at 480 open-circuit, the pack likely sees somewhere between 400 and below 480 VDC. Since it's switched on and off by the PWM, it's probably fair to think of the average integrated voltage over time with the duty factor. So I think your numbers at the cells can still jibe with a source that starts at 480 no-load.

In any case, the current through the "pump nozzle" is well north of 200 Amps, which is pretty remarkable.

Volker.Berlin | 28. september 2012

Back to the original topic, this guy did three supercharges in a single day, and was obviously advised to do so by Tesla:

That's probably taking it to an extreme, but it does work. It still looks a bit suspicious to me: All these rumors that supercharging would significantly impact the battery, and should only occur like 2% of all charges or twice a year max (depending on whom you asked) was originating from Tesla. And now all of a sudden this is a non-issue?

Not sure what I'm supposed to think of it. If it's true, then why did they do themselves the disservice and gave out the disconcerting preliminary information ahead of time? And if there was something to this information, how did it fundamentally change within weeks?

Brian H | 28. september 2012

The only logical resolution of the discrepancy I can see is: don't fully charge (to 90%++) on a supercharger. Short of that, NBD.

MB3 | 28. september 2012

It may be that they worked out a new delivery system that works better than as early models. It wouldn't be the first time they leaked information before it was finalized.

adlink | 28. september 2012

I agree with Volker. We have been told all this time to limit the use of superchargers and now all of a sudden it's not a problem??? I hope we get an official statement from Tesla not only stating its a nonissue but explaining what has changed that makes it ok. I would hate to get the car and find out five years from now that I experienced greater battery degradation because of the use of the supercharger.

Brian H | 29. september 2012

strangely, it might be a blessing in disguise. You'd have to replace it with a new type at half the price with twice the range and 1/4 the charging time and no heat or cold limitations and ...

Or SLT. ;)

July10Models | 29. september 2012

'Charges to 50% at high rate, then tapers. After 80%, it slows more to protect it (but keeps charging)'

that is the key to prevent battery pack degradation. So in the future when SC output increases, there better be a beef up cryogenic system to support it. for now you can't charge to 100% in an hour.

Vall | 29. september 2012

Bummer that they announced the 60kWh supercharger is a $2000 option. And they explained that all cars are built with the hardware, but enabling it will cost money.I really don't qite get how can the software for that be so special that it costs $1000 to install and verify. This is like saying they will charge you money for the shakedown tests of the car in the factory or the water-proofing tests.

Volker.Berlin | 29. september 2012

Bummer that they announced the 60kWh supercharger is a $2000 option. (Vall)

There are two other threads dealing with this topic in some detail:

Would be nice to stick to the effects of supercharging on battery life in this thread.