Tesla's next-generation Superchargers should be much faster

https://www.engadget.com/2016/12/26/tesla-supercharger-v3-teaser/

by electic • 10 years ago

59 68 10 years ago

jawbone3• 10 years ago

Is it just bulk that makes the batteries non replaceable? Putting in charged ones are after all the simplest way to speed up charging if the replacement is relatively simple, and a well proven solution for other battery powered devices.

zwily• 10 years ago

They are replaceable in minutes: http://fortune.com/2015/06/10/teslas-battery-swap-is-dead/

They're focusing instead on fast charging.

dexterdog• 10 years ago

This sounds like a program that was designed to fail so they could say that they tried. I don't see a ~400mi charge from zero ever happening in the sub-10 minute range. A swap is the only way to do that without a major technological breakthrough. Swaps have their own logistical problems, but swapping battery packs is the best solution for cars, phones and anything that needs a battery that can be easily swapped.

gonehome• 10 years ago

They had a swappable demonstration a couple years ago and the model s supports it.

Main issue is a social issue - people like to have ownership of their own battery pack.

IanCal• 10 years ago

Perhaps less of an issue with trucks? I expect in that situation it'd be decided much more on economics than personal freedom.

jessriedel2• 10 years ago

They had a swappable demonstration a couple years ago and the model s supports it.

This was basically a ploy to get government dollars. The tax rebate per vehicle was partially determined by capabilities the car had theoretically, even if they weren't deployed in a useful manner.

http://www.csmonitor.com/Business/In-Gear/2015/0312/Tesla-ba...

http://www.latimes.com/business/autos/la-fi-hy-tesla-battery...

Main issue is a social issue - people like to have ownership of their own battery pack.

What's the evidence for this? People have no trouble with propane tanks they don't own for gas grills.

greglindahl4• 10 years ago

There's no evidence about Tesla owners and battery pack ownership -- Tesla has never offered anything but purchase or lease of the entire car.

_ph_2• 10 years ago

With batteries the size Tesla has, you really want to take a break after several hours of driving anyway. So the supercharger time adds only little delay to your travel.

abelsson• 10 years ago

For reference, gas contains about 33kWh of energy per gallon, and if we assume you pump 20 gallons in 5 minutes when you fill up your car you have an effective energy transfer rate of about 8 MW at your gas pump. Even if we give an electric vehicle a 3x efficiency ratio, we still need about 2.5 MW to be equivalent to the old petroleum infrastructure.

the84723• 10 years ago

The comparison is not quite that easy. The old petroleum infrastructure is more centralized.

You can get electricity almost anywhere, adding a charging station to parking places or garages is far easier and safer than hypothetically laying gasoline pipelines everywhere. So there are more opportunities for partial charging when the car is idle.

PietdeVries• 10 years ago

And in addition: the efficiency of a petrol-engine is much lower than an electric engine. So you perhaps only take in half of the fuel, if it gets you just as far you have what you need, isn't it?

kirushik• 10 years ago

easier and safer than hypothetically laying gasoline pipelines everywhere

Ironically, that's safer exactly because electricity won't give you those MW-scale powers.

cypherpunks01• 10 years ago

What do you mean "laying gasoline pipelines everywhere"? Gas stations do not connect to any utilities apart from the regular electricity, water, and natural gas, all of which require a physical connection to centralized infrastructure.

ajross3• 10 years ago

That's only doing the math on the instantaneous flow rate down the nozzle/plug. Pulling into the station, waiting in line, hitting the rest room and paying the bill need to be included too to get a relative penalty.

Also: if that 33kWh/gallon number is a heat of combustion (I'm too lazy to convert to real units or look it up myself) the efficiency gains of an electric motor vs. an internal combustion engine is significantly higher than 3x, I believe.

phil212• 10 years ago

Pulling into the station, waiting in line, hitting the rest room and paying the bill need to be included too to get a relative penalty.

This is not the average experience for a US driver. Very few gas stations ever have all their pumps utilized, even during rush hour. I haven't gone into a gas station in years, or waited on paying the bill - everything is automated at the pump.

I would put the "convenience store" aspects at par - you either want some snacks or need to use to rest room or do not - the fuel type doesn't change that.

Payment again I'd put at par - swipe a credit card at the "pump".

Maybe add a minute for "average wait for a free pump" to the gas station model, but I'd argue that problem would be even worse (or at least par) with electric charging.

The only real win I can see is that you could do other things away from the vehicle while it charges (attended vs. unattended fueling) which lets you parallelize some activities above. But that only becomes useful once the refueling times become within the average potty/snack break at a gas station - and we're no where near there yet.

hwillis6• 10 years ago

More like 36 kWh. Average mpg of new cars is 25.5 mpg (.71 mi/kWh) while Teslas get 3.2-3.8 mi/kWh so the efficiency ratio is closer to 5x. With 4 gallons/minute, that's 7.2 kWh per gallon/1.73 MW. In the US pumps reach up to 10 gallons/minute so 4.3 MW and 17.3 MW for truck-filling pumps. Not all pumps hit 10 gallons/minute though.

2 or 3 MW would charging power would require a really specialized battery and will probably never be worth it. The real advantage of an electric car is letting it charge overnight and adding some extra time over long journeys isn't a big inconvenience- its less time than unexpected traffic would take up. Plus the time is overall made up for by never having to fill up if you come home to charge overnight once a week. Same thing applies to trucks. An hour-long fill up once a week gets replaced by nightly charging.

saurik2• 10 years ago

Average mpg of new cars is 25.5 mpg (.71 mi/kWh)...

This is not a reasonable way of doing this math because it loads the numbers with "people who want a large and heavy car can't or wouldn't buy an electric, pulling down the average miles per gallon for gasoline powered vehicles"; to do this comparison fairly requires looking at the energy conversion efficiency of the engine, tank/battery, and transmission in isolation of the rest of the car body. Another way to put this: if you manage to buy an electric Hummer, you are going to be spending an insane amount of time charging it, because it would use as much more electricity as it uses more gas ;P. If you really need to estimate this using miles per gallon, you need to look at a gasoline-powered car which looks like a Tesla (being about the same size and contour), not the average new car purchased by a consumer. (FWIW, a quick eyeball of this is looking like 40 mpg.)

vvanders4• 10 years ago

Not quite, ICE engines are governed by the Otto cycle which has a theoretical efficiency limit of ~37% and most get less than that.

In terms of real-world power usage you're close to 1/3rd of that(unless the car captures the excess heat and reuses it).

iheartmemcache2• 10 years ago

If we're talking 'next-gen' tech vs 'next-gen' tech, let's be a little fairer, newer cars are using the Atkinson not the Otto[1]. Throw in the fact that we're no longer tied to a camshaft for timing[2], cylinders can be shutdown at will (e.g. you're in bumper-to-bumper on the 405 or 101, your Benz-AMG or Stage 3 Mustang doesn't really need all 8 cylinders firing) and the fact that most manufacturers have at least one car with the option to reclaim that heat (i.e. even Ford Mustangs, notorious for being gas guzzling pony cars, have a turbo-hybrid configuration option) and things for the ICE look a little less bleak.

I'm all for pure-electric cars but we're still a long way from Joe the miner in Kentucky from being able to drop $1800 on a 2000 Toyota Tundra and having it be able to get him reliably from the jobsite and back. That's not even factoring in the whole capacity-decrease-with-use (and even non-use-- deterioration occurs simply by just storing cells at full capacity for long duration -- of lithium.

Even with the best, most conservative profiles on a battery-module controller for anything lithium based, good luck getting > %50 of cell capacity 5 years down the road of a daily driver [edit: 7]. Anode deterioration (at least, last I seriously researched it for projects requiring portable units for driving larger loads than an average car was ~1.5 years ago) was still a problem even in the lab.[3]

My sister abuses her 2004 Civic coupe to the point where I think she's still running a stock air filter and runs 30-35k between oil changes[4]. This was a run of the mill car she's had since god-knows-how-long and she's still getting 22mpg city [5] ~26 highway on an automatic transmission.

tl;dr -- In terms of total costs :

- capital (purchase) / delivery fee

- operational ($ of petrol for ICE per unit travelled/$ of energy from your power supplier per kw/h), insurance

- maintenance (tire wear, brakes, battery module(s) replacement(s)) over, eh, 5 years from out-of-the-showroom-into-your-garage, I'd be surprised if you saw the electric dollar-for-mile-traveled outperform it's ICE counterpart.[6] I'm far from the forefront of Li, but I do have a few friends in that field (both in academia and in industry) -- even the most optimistic don't see pure-electrics reaching a TCO parity point of an ICE for the consumer in less than 10 years.

[1] http://www.greencarreports.com/news/1091436_toyota-gasoline-...

[2] https://www.youtube.com/watch?v=FJXgKY2O4po FreeValve as explained by that really enthusiastic "Engineering Explained" 24 year old automotive engineer, dumbed down to the point where even I can grok it.

[3] Rumor had it, DARPA was using some crazy proprietary stuff that managed to completely nullify dentrification, but if they've managed to accomplish that anodic behavior, there's no way it's going to be released for public usage -- rather, it'll remain hush-hush minus 50 PhD's in metallurgy, and Lockheed drones all of a sudden posting performance numbers +30% from the last revision.

[4] She's not using those long-lasting synthetics that have additives to SeaFoam (yeah, I'm using it as a verb) out carbon build-up on the cylinders and what not, in case you're wondering. Just cheapo 5w/30.

[5] That, albeit was with me driving in 'conservative' mode rather than "hmm let's see the 0-160 on this McLaren".

[6] And I'm 100% sure if you bought a 3 year old variant of an ICE vs a pure-electric, it's no contest -- https://www.edmunds.com/car-buying/drive-a-nearly-new-car-fo... -- ignore the link bait title, it's just about the FMV of cars as a function of time.

[7] In addition to the response I made directly to child-poster, I'd like to concede that it is very possible he's ran 43k miles (i.e., literally at least a thousand cycles, likely closer to mid thousands) with a retained 98%. He makes a very valid point in bringing up the variance of cell capacity deterioration. I'd genuinely love to see some cal'd equipment with your standard dummy load and power analyzer log setup to see the data. (I ain't no fancy electron whiz but I can read me a chart or two.)

The take away is that overall capacity is a function of usage. I could probably get in the lab and simulate 43k miles of load in LabView discharging/recharging every 10 miles while keeping the thermal properties controlled as all heck and see 99.5 capacity retention, but these, again, aren't Joe's driving patterns.

edit 2: @maratd: See my edit 1/[7] (which I presume I was writing while you were drafting your response). I think we're largely in agreement re: usage properties being highly influential. My response to the OC (original child poster) addresses the deep-cycling cooling. As this has turned into a post with 8 endnotes, I think I've crossed the threshold of reasonable discourse.

Allow me to close with a quick remark re: BMC's on your power drill. Anything half decent will have active thermal monitoring specifically because of the reason you stated (much to the chagrin of blue-collar workers everywhere). "Ok, last weld before quittin' time..." paddle trigger actuates, worker expects wire-wheel to start spinning a to clean the slag of iron oxide off the root weld. nothing happens because the thermocouple on the motor armature triggered a lock-out "PC LOAD LETTER WHAT THE HELL DOES THAT MEAN?"

drzaiusapelord• 10 years ago

On the flip-side I don't have a gas station in my garage or my work's parking garage, but either can be trivially outfitted with a 220v plug. Ideally, one's recharge strategy shouldn't be like filling up a gas car. You should be plugging your car in for overnight charging and only using these types of stations in a pinch. With gas cars, I have to use these stations. They're literally my only choice. I couldn't build a gas station in my garage even with vasts amount of money due to regulatory, safety, and environmental concerns.

Its also more reasonable to tap into overnight power as to not stress the daytime powergrid.

gas contains about 33kWh of energy per gallon

ICE are about 20-30% efficient. So 70% of that 33kwh is lost to heat and other inefficiences. Electric cars are about 70-80% efficient, so you actually need only 1/3rd the energy capacity in this kind of calculation to match ICE/gas.

ebbv3• 10 years ago

The thing to keep in mind when thinking about EVs is that while they may be slower to fill up at stations where you have to stand there like the Tesla super charger stations, this is a small minority of the charging most EV owners do.

Most of the time my LEAF gets charged at home in my garage. We only use public chargers a handful of times per year. When we do, it's stations in parking garages or public parking lots. Which means we plug it in and walk away. We don't have to stand there with it while it charges. If it takes a couple hours that's fine.

People focus on how fast they can recharge their EVs while they are standing there waiting for them because they are used to having to go somewhere to refuel their gasoline powered car. One of the great things about owning an EV is you recharge at home.

pbz• 10 years ago

Except that Tesla is now charging $0.40/minute of leaving the car plugged in after a full charge is reached. They do this precisely to prevent people from "abandoning" their car while others wait in line.

niftich• 10 years ago

While all of this is true, charging time is an issue because it limits range. A gasoline powered car is just a 5-minute detour away from doubling its range, which compares terribly with the sort of vehicle you're going to want to walk away from to do something else while the charging does its thing.

Apparently people leaving Teslas longer than necessary in the supercharger spots is already an issue [1] that they are trying to rectify by charging for overstays.

[1] https://news.ycombinator.com/item?id=13204120#13204455

amelius• 10 years ago

Can't we have "charging lanes" embedded in major highways, and cars fitted with retractable sliding contacts? Or something like that?

hwillis6• 10 years ago

Assuming he's not being sarcastic, it could be power aimed at semi trucks. That would probably be sub-megawatt for regular charging, and 1-2 for supercharging. It's gonna be a lot more important to have a well-developed charging network for trucks since they are working vehicles: nobody is gonna buy a truck and then sit around and wait for it to become profitable to drive. Maybe we'll see some extra-large charging spaces opening up soon...

https://www.reddit.com/r/teslamotors/comments/4u0yci/why_i_w...

stuckagain• 10 years ago

Long haul truck fleets will be much more suited for swaps than recharges.

yessql• 10 years ago

It would probably be easiest to swap the cargo onto a charged tractor. Since there is no driver, you just have an automated station that swaps the tractors and the cargo goes on its way. Swapping a giant long haul battery would be very cumbersome.

I agree though that swapping and slower charging would make more sense than trying to charge at some multimegawatt level to reduce the cargo transit time.

birdman3131• 10 years ago

Not really. Unless you are driving team you still only get 10-11 hours of driving a day. (iirc. I know the regulations have changed a LOT since I grew up in a truck in the early 00's)

There is plenty of time to recharge a truck over night at a truck stop. The issue is gonna be infrastructure at the truck stops. I am gonna guess at 150-300 spaces at most truck stops. If the majority of trucks go electric then I am not sure the electric grid's connection to the truck stop is gonna be able to support that.

Anybody know the math on how much electricity would be needed to take an 80,000lb truck 700 miles? (700 miles would be on the very upper end of the scale but you want that kind of range to accommodate for climbing hills with a full load.) And after that the math for charging say 100-200 of them? (I doubt the truck stops will all be charging at once)

marcosdumay• 10 years ago

Trucks stay stopped a lot of time for loading and unloading. Most could easily have an 1 hour charging without any issues.

Superfast chargers would be great for self-driving trucks making long distance trips. But then, train corridors probably beat those on every way.

For vehicles where somebody is inside, I don't really see the point of 5 minutes charging. People need to rest and eat, and nobody does that in 5 minutes. Plentiful slower chargers would be a much better selling proposition.

hwillis6• 10 years ago

I did some analysis and think batteries will be somewhere 1-1.5 MWh for tractor trailers. 3 MW would still take 20-30 minutes to charge that. The middle ground isn't very useful as delays on deliveries lose a lot of money. Even an hour long delay cuts into profits. Unless you can charge at .5-1 MW, its not any more useful than just charging overnight.

vegabook2• 10 years ago

Even 4-5 minutes is still an eternity if you're in a queue behind 10 cars during the holiday rush, and have to 'fill up' twice to get to your destination. What would be a 20 minute wait for gas becomes an hour, for something that doesn't even give you the same range.

the84723• 10 years ago

How often does that happen per year?

geodel• 10 years ago

I do not know but I do want to reach friends and family as quickly as possible so that we can all spend time on our tablets and phones at same place.

_ph_2• 10 years ago

For long distance travel, one would install some more superchargers than fuel pumps. In day to day driving recharging should not be an issue at all, as it should happen over night anyway, you start with a filled up car every morning.

vegabook2• 10 years ago

600 KW is some chunky wattage. It's unlikely you can charge very many cars at the same time without having a power station next door. Delivering, for example, 10 megawatts to handle 15 cars simultaneously, requires some very heavy electrical and safety engineering, which would be very costly. You could run pylons along the highway, but then you'll need an high-wattage electricity substation next to each charging forecourt to bring the voltage down.

A gas fuel tank under a service station, however, is cheap, and is limited only by the size of the forecourt in how many cars it can simultaneously service. And we still have the problem of charging time. You'd probably talking a forecourt capable of charging 100-200 cars simultaneously during peak times. That's 60-120 megawatts on Musk's fast charge. That's enormous. It's an entire small power station.

For any long distance, my sense is that electric cars are still at a heavy disadvantage to the ICE for the foreseeable future, even assuming Musk's optimistic charging cycle projections.

Let's face it, gasoline still has some miraculous energy storage density / transportability advantages.

wklauss• 10 years ago

It's unlikely that you'll hit those wait times due to other cars at the same supercharger, I think. Not all trips require a visit to a supercharger and unlike ICE, owners of electrical recharge daily at their homes.

It could happen for some popular routes, but it will be a minor nuisance and easily fixed with more supercharging stations on the routes that are more congested.

makecheck• 10 years ago

The real problem with shared ports is that cars still occupy stations when they’re done charging, and they are not even required to “plug in” while using the convenient parking spots.

You need a way to force a car to start charging while parked in special spots, and force it to leave when done (the Tesla actually could move itself out of the way automatically, if only there weren’t a charging cable attached).

amluto2• 10 years ago

I wonder what the Tesla charging contacts are rated for. Assuming they keep the straight-to-battery model, 350kW is around 1000A. I think Tesla chose the best available contact for its size (I forget the brand name), but 1000A is a lot for that size contact. They may have to devise a way to actively cool it.

I doubt that they want to start supercharging at higher voltage. A DC-DC converter at that scale will be fairly large. I suppose they could add some contactors internal to the battery pack to change the cell wiring to double the voltage and halve the current for charging purposes.

greglindahl4• 10 years ago

Higher-powered Tesla superchargers already have an active cooling system in the cable.

neon_electro• 10 years ago

I don't claim to be an expert, but it appears that Tesla has experimented with liquid cooling Supercharger stations before: https://electrek.co/2016/07/21/tesla-ends-its-thin-liquid-co...

In the above case, they used liquid cooling to make the charging cable diameter smaller, but perhaps the technology can be used to make the regular Supercharger cable capable of handling more power.

amluto2• 10 years ago

Cooling the cable might be easier: you can make a hollow braided copper tube, insulate and seal around it, and run liquid through it. But you can't run liquid through the contacts unless the car has plumbing for it, and I doubt it does.

Tesla's next-generation Superchargers should be much faster

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