Tesla’s promises don’t compute with current physics and economics of batteries | Hacker News Reader

Tesla’s promises don’t compute with current physics and economics of batteries

bloomberg.com

110 pointswatchdogtimer126 comments

The Tesla superchargers currently charge at around 2% a minute up until about 80% which is 40 minutes to hit 80%. Tesla is advertising 400 miles in 30 minutes which is 80% of the 500 mile capacity. What is so hard to believe about a 33% improvement over a couple year old tech that is a couple years from release?

Here are current industrial/transportation/residential electric prices in US [0]. They think Tesla will pay 40c a kwh??? What a joke. Sure if you look at constant demand facilities and extrapolate their pricing model with low average demand to megachargers you can come up with a ridiculous number. You can literally run diesel generators and generate electricity for a lower cost. This is so hysterically asinine I can't believe Bloomberg published this article. Not to mention a huge amount of charging can happen overnight when drivers are sleeping and electricity prices/demand are super low.

Pushing a lot of power through a wire is a solved problem. So what they need to push 10x through one connection instead of over 10. We are talking about a modest increase in % charge rates. That is what matters. All else equal you can charge a percent of your battery capacity not some arbitrary fixed number.

This is an embarrassingly poor article. I think the one the worst things about the current tech shortage is now we have all these arts/business majors doing technology writing larping like they know the difference between a watt and an amp.

[0]https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

Look at charging rates in watts (watt hours per hour) instead of in percentage; those semis have much larger capacity batteries, so they need a higher charging rate in W to charge 80% in 30 minutes than a vehicle with a smaller battery.

They don't have larger capacity batteries. They have batteries with more cells. Sure, the total charging rate is a higher Wattage, but you can charge cells in parallel.

The scaling here is exactly the same as with the "larger battery" versions of the Model S having more horsepower; higher capacity = higher throughput when you're dealing with battery banks.

Wait, are you concluding that having batteries with more cells is not the same as increasing the capacity of the system?

For any battery system, the capacity is the product of the number of cells and capacity per cell.

My point is that having a larger capacity battery automatically increases the wattage at which you can recharge. It's not like a gas tank where a 100L tank takes longer to refill than a 50L tank.

No, capacity of the battery isn't what determines the wattage at which you can recharge. It's the physical power supply constraints.

If I have a 250v, 25 kWh battery, I can charge it at 250 V, 100 Amps for 1 hour or at 250V, 1000 Amps for 6 minutes.

What charging rate I select depends on the voltage and chemistry in the battery. Can the battery support charging at such a rate. The charging current rate is limited to the max operating current of the battery.

If the above battery can supply a max current of say 50 amps, then you will have a max charge rate of 250V, 50 Amps for 2 hours.

What makes it confusing is that the charging rates are given as 10C, meaning 10% of nameplate capacity.

Might be fererring to nameplate power capacity.

nC means n*capacity/time, so 10C for 10kWh is 100kW

That’s wrong. 10C means 10x the nameplate capacity. If I have a battery that outputs 40Ah, 10C means I can give it a charging current of 400A.

Here’s some napkin math based on a few assumptions.

Assumptions: The article is correct and it’s an 800KW battery pack for the semi. I’m also going to go with a conservative assumption and assume 2C charging rate for the battery pack. I’m also going to assume that the semi will have the ability to take in a 480V charging current because it simplifies wiring and is easier to get in an industrial capacity.

With those assumptions, you’ll need 1.6MW of power, something that can be easily delivered with less than eight 500MCM cables (roughly 1” copper cables including insulation that weigh about 2lb a foot and are still rather flexible). This seems in line with the charging port photos I’ve seen for the semi. Neither the cables or the power needs are that dramatic, there’s wind turbines that put out that much power individually along I-70 in Kansas for example where there is thousands of them.

This makes sense--it explains why it takes as long to charge my mobile phone as a model S. Obviously different chemistries can charge at different rates, and the power supply and cooling needs to scale with the battery capacity, but if these are scaled then two batteries which use the same cells will recharge in the same time regardless of how many cells are in the battery.

I suspect Tesla's grid storage already proves this point.

I would imagine that the difficulty in charging is proportional to the cell's capacity, so charging 2*n cell shouldn't be any harder than charging n cells, as long as the cell's capacity is the same. If you increase the capacity of a cell, then you might have to innovate.

Truckers are even required to take a federally mandated 30 minute break[0] during the day, during which the truck can be recharging.

Industrial applications already consume much more power than an entire Megacharger site, so supplying the charger with power is an already solved problem. Getting power from the charger the truck is again, a solved problem in the industrial space. I can order an off the shelf industrial connector [1] that does 1000v @ 400A, which means you might need two of them. Truckers already use 2 pumps to fill their truck, so even that is not out of place.

[0] https://www.fmcsa.dot.gov/regulations/hours-service/summary-... [1] https://www.connector-techals.com.au/manufacturer/rauscher-s...

The regulatory info only gives information on the way things should be with regard to how truckers and the interstate highway system works, but I would suggest that before you invest on this hypothesis, talk to some truckers earning $0.50 per mile. And look at where semis actually park when they're taking their 30 minute and 11 hour breaks, before deciding how fast this transition will occur and how much infrastructure will have to be in place along the major cross country interstates like I-70, I-80, I-35, etc., before a trucking company or an independent trucker decides to go all in on electric.

(I don't know the answer, but I strongly suspect that regulations are not going to be the driver of the adoption of this tech. Short haul or "hot shot" could be better suited for electric and autonomous. Show me some progress there first and I will buy into some actual disruption. If you want a research assignment, take to the interstate back and forth across a couple of flyover states and stop and see where the trucks actually are.)

I’d argue that these trucks would be a much better fit in Europe than the US. Here truckers can drive a maximum of 9.5 hours a day with a 45 minute break. These are mandated by law and the pentalties are severe for going over these limits.

The range also lends itself nicely to this. Over the course of a day a trucker would drive a maximum of 855km (they are limited to 90/h), so with a short fast charge during their break the 500 mile version could easily achieve this, then over night it could be charged slower.

In the UK we also have very narrow delivery windows e.g. Be at Tesco in this 30 minute slot or pay a steep penalty. Scheduling a charging slot will not add much difficulty.

Logistics researchers have also been working on this problem for years. You can find paper after paper in the literature.

On other hand it looks to be about a meter longer than most trucks in Europe so that would mean it has to use shorter trailers, and I do not think the weight has been released yet, but I think it is going to be more than trucks now. And the maximum permitted weight in EU is 40 (except if you transport containers then it is 42).

>And look at where semis actually park when they're taking their 30 minute and 11 hour breaks

and you believe either the Trucking companies, the Regulators, or Telsa give a shit what works for Actual Human Truckers....

Telsa is looking ahead to full automation anyway so humans are seen as a inconvenience, and if they make it hard on Truckers that will just give them addition ammo for any concerns regulator have in replacing Truckers with Automation. To these companies The fact that is might be hard for Truckers to find a Charging station that falls in line with Hour of Service rules just proved we need to eliminate the humans

Good point, I guess, although I was responding to the parent's post that cited meatworld-based regulations as a compensatory excuse for the need for frequent recharging.

Sure, many electric and autonomous vehicle problems go away if we "simply" re-engineer millions of miles of roads and infrastructure in the country. Now you've got two problems.

All these EVs use roughly the same small cells, right? Essentially thousands of the same cells used in hobbyist RC aircraft (with which I’m fairly familiar)?

Unless I’m mistaken, each little cell should theoretically be chargeable in parallel, limited only by heat, massively parallel wiring, and the one massive input carrying ridiculous current.

In theory, if one cell takes 30 minutes to charge, all cells could be charged in parallel in 30 minutes. Obviously this is ignoring the challenges I mentioned, which generally don’t apply to the relatively small RC aircraft with which I have experience.

If all of them are connected in parallel, then you are right. It's like filling an array of glasses in the rain.

However the superchargers connect to the vehicle through a power port, which is relatively small. So it may not have as many parallel connections. You could split the charging to individual cells inside the car, allowing for parallel charging of all the cells simultaneously, but that means that the supercharger has to handle the cumulative power requirement of all the cells in parallel. So if you have 500 50W cells, then the super charger has to have the capacity to handle 25 kW of power. And that much power requires some very bulky cabling, even with a 3-phase supply.

The parallel connections are visible: https://insideevs.com/wp-content/uploads/2017/12/Tesla-Semi-...

Yup, definitely 3 phase. But then it has to supply a charger or an array of chargers on the vehicle that convert the power to DC, leading to increased bulk and costs. So we're back to the 501 terminal plug again.

Perhaps they’re looking into some even superer superchargers for the tractors. It’s a shame they apparently publicly abandoned the hot-swap battery system, although I can’t imagine they’re not still working on it, especially for the tractors.

You'd still have to transfer the heat from the cells inside the battery. That would probably lead to a design with increased battery surface, maybe even a radiator or cooling lines.

Already what happens. GM and Tesla use pumped liquid glycol for heating/cooling and some other companies use refrigerants.

Interesting. I did not know that. I always figured they must need to manage heat, at the bare minimum by preventing huge draw for extended periods of time. Do you know where they radiate the heat, given that most Teslas don’t (to my eyes) have visible grill vents?

You only need to do that when charging the battery.

Oh, do the batteries not heat up when discharging quickly as well? I know next to nothing about battery chemistry, but for some reason I just intuitively assumed they did. RC aircraft batteries can certainly catch fire if something causes them to discharge extremely quickly.

They discharge slowly during driving, unless you floor the acceleration while driving up a slope, but I'm sure there are some kind of limits in place, to prevent the user from draining an unsafe amount of power from the battery.

All Teslas have a grill in the front, it's down low. The battery cooling system is shared with the cabin cooling system.

It's typical anti-Tesla propaganda.

Agreed. I don't know why there's so much anti-Tesla sentiment on HN.

Smart people like to try to take down the smartest person in the room.

Comparing on a percentage point basis, you have to ensure that the underlying physical system is equivalent, in this case, the capacity of the batteries.

Current superchargers charge at 2% / minute. I am assuming that's the maximum rate of charge, given the current supercharger infrastructure.

Lets assume that 2% / min is, say, at a 100 kW power level.

When charging a truck, assuming the supercharger technology isn't changed, the charging will still be at 100 kW power level.

So if the truck has 10 times the battery capacity, then the equivalent %age rate of charge will be 0.2%, not the same 2% as the capacity of the battery to be charged has changed.

Personally I think Elon is either going to add multiple charging inputs per truck and combine it with a special supercharger, or have some sort of port in the truck to which a special connector is connected to transfer huge amounts of power safely, not unlike a dock at the under side of the truck, or maybe the front.

I'm no battery expert, but is it possible that they have several battery compartments that can all be charged simultaneously? Thus reducing charge time?

Edit:

Just read the latter part of your post after I wrote this. I think this is the most likely scenario. "Personally I think Elon is either going to add multiple charging inputs per truck and combine it with a special supercharger,"

Yes it's possible. We could have a power port like a VGA cable with say 10 or 20 independent supplies, simultaneously charging the different battery units.

However those connectors will be very bulky and heavy. Maybe Elon is thinking of a mechanized system, say a power robotic arm sort of thing, or maybe tech similar to the instant battery changing station he demoed a few years back.

They do call it a "megacharger," and the port appears to have multiple connections

https://www.teslarati.com/tesla-semi-megacharger-charging-po...

Half of the stories about Musk projects are just rambling about how what he's doing won't work.

I find that doing something that matters in life is not just hard because the task is difficult. It's hard because of all the people that gets in your way.

It's already painful to see people doing nothing by themself. Or even not helping the cause of others. But it's infuriating to see how much energy they spend to go against your attempts.

I'm just constantly surprised and exhausted at the kind of pessimism and cynicism on display in any Tesla thread. Even people who have no stake in the company or its competitors feel compelled to chime in just to say "it won't work!"

I don't get it. For better or for worse, Tesla has made the idea of electric cars feasible to the mainstream.

Surely, that can't be a bad thing. Why knock down the idea so aggressively?

I'm starting my own business myself, and I notice there are fundamentally 2 kinds of people.

One are the risk takers. Who know risks are involved, but do it anyway, sometimes against all odds, because the payoff (in any form) is big or huge. The risk is worth it for them.

Then you have the conservatives, who just don't want to fail. They take no risk, don't step out of their comfort zone, because they might fall down, they might fail. They want to be like all other people, average and safe.

I'm not saying either of them is good or bad. They just have a different take on life. I think conservatives are happier.

Problem is that when a conservative sees a risk taker in action, they don't understand it. They see all the possible ways on how this thing can fail. They ask why these risk takers don't see how this can fail.

Point is that the risk takers do know how things can fail, but do it anyway (ok, sometimes you do have stupid people who don't know). If it fails, they can proudly say "See I knew it! How stupid was that". Conservatives like to remain in their safe zone, where they know how things go. The risk takers always want to change things.

If anyone has another take on this, I would be glad to hear it.

I tend to agree, although I think this is probably a spectrum, rather than binary. Or maybe a bimodal distribution? I think that people probably tend one way or another, but we all probably display both reactions in different areas of life, at different times, etc.

I also think the terms you used probably aren’t ideal, because they imply a political connection that might make people resistant to your premise. It reminds me of the maker vs taker thing.

I like to think of it as reasonable vs unreasonable, as in the George Bernard Shaw quote:

“The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.”

I totally agree. The naysayers aren't convinced that my designs for an interstellar pogo stick are viable. They just don't get my vision. Sure, there are some specifics to iron out and maybe it won't work but at least I'm trying to change things.

Best of luck to you.

They don't even need the 33% improvement. They could just add that much battery and fake the charge rate by misinforming the user about the charge rate. I.e. say it took 30 minutes to get from 0% to 80%, but really you went from 30% to 80%, the car just shuts down at 30%.

They already have firmware unlocked battery capacity in their currently shipping cars, so this isn't some wild conjuncture. The margins on these vehicles are huge, they can just decide they'd like to pay for marketing by cutting into some of those and shipping more batteries with each vehicle.

>"The Tesla superchargers currently charge at around 2% a minute up until about 80% which is 40 minutes to hit 80%."

I am curious what exactly happens at 80%, does that 2% a minute rate drop off precipitously? If so what is the reason for that?

Lithium Ion batteries are generally charged using a two step process of constant current then constant voltage. https://www.digikey.com/en/articles/techzone/2012/nov/consta... If 80% is the set point to switch over from constant-current to constant-voltage, then yes, the charge rate will drop continuously until it reaches full charge.

If this were any other company making such unsubstantiated claims that didn't have any basis in the reality of the underlying technology, they'd be getting roasted here.

I don't really agree. If another company rolled a 200kwh car out of the back of a truck, did a few passes of the stage, gave passengers rides (high speed launches) for a while, and then reported ~60% battery remaining, I think most would believe them.

We would also wonder about making it to production, but Tesla actually has a halfway decent track record at that.

> If another company rolled a 200kwh car out of the back of a truck ...

That's the thing. They didn't. The roadster concept didn't have 200kWh in it at all.

It might not have exactly 200kWh of battery installed, but one reason for planning such a large battery is to be able to support the neccessary current levels for the accelleration they have demonstrated. So they couldn't have just put a small battery in the car either.

At the show, they were saying that it did. Do you have some evidence to the contrary?

Well, the article makes it sounds like they are defying physics - "breaks laws of batteries"? Then also quotes

>“I don't think they're lying,” Jaffe said. “I just think they left something out of the public reveal that would have explained how these numbers work.”

There are no laws here, just advances in battery tech, and people believe Tesla is at the forefront of that AFAIK. Sure, they might be making claims that are hard to believe, but isn't the point of Tesla doing exactly that?

You may be right. But there's nothing wrong with it. Tesla has done amazing things, and so has SpaceX. Yes, they're in the habit of being late. But neither has, as far as I can remember, ever produced "vapourware" they didn't eventually start selling.

For a nice reference: see this comment sceptical of Tesla's capability to deliver this 100MW battery in Australia in 100 days. Which was just recently completed on time. The tone reads surprisingly similar to the Bloomberg article ("To say nothing of the near 50 degree weather beating down on old infrastructre that spans thousands of very sparse kilometers.") https://news.ycombinator.com/item?id=13838355

People, and companies, have reputations. Those have to be taken into account when judging their claims.

Note also that all of the claims of the article are in the "this is hard" territory, not any actual "this is perpetual motion" sort of impossibility as the title alludes to.

The example that seems easiest to judge is doubling the capacity of the roadster battery: The current Model S battery is a rather thin sheet underneath the car. I have absolutely no doubt that you can fit twice the volume into the same frame. It gets only easier if there are any advances in battery density, or if car grows only slightly in every dimension.

Gonna bet that being an hypercar they got the space for batteries by having a lower ground clearance

That said I’m still skeptical aboutthe figures given but not because of the batteries - it takes lot of engineering to keep a car togheter at those speeds: most of the components will be quite close to the limit of material science and tesla is not exactly known for its quality control pipeline.

What would prevent the battery from having a segmented design so that multiple segments can be charged in parallel? Is there something about the chemistry that requires the entire vehicle battery to be a single unit?

At some point the size of the connector TO the vehicle is going to be the limiting factor.

I was thinking of batteries connected in series with a mechanism to separate the connection during charging. The main connector would be the same. Perhaps this is just not possible with huge batteries?

Edit: Oh I get it...the charging port is what you meant.

Exactly my thought. Relays that connect the batteries in series for charging and reconnect in parallel for driving.

In the case of a truck, that seems less likely -- surely they could come up with a design that hooks in 2, 3, 10 plugs the moment the truck is ready to dock.

Their design has 4/8 ports: https://insideevs.com/wp-content/uploads/2017/12/Tesla-Semi-...

Nice! I guess the width of the wires is the limiting factor? Or a cooling system? Regardless, curious to hear an informed analysis.

That is how they work today. This is Tesla's current state of the art (larger) battery. As you might image in takes more than 1-2 to run a car.

https://i.ytimg.com/vi/ga4L1w66AbU/maxresdefault.jpg

The problem is disgustingly parallel.

The battery is composed of cells connected in parallel and in series. Say P parallel strings of S cells connected in series each. You want your cells to be balanced: charged the same amount.

You can charge every single cell individually, simultaneously, if you design your connections to support it. IIRC our packs were wired to charge the internal cells in pairs.

If you think about it, though, with a given max current I = dQ/dt, you need the same amount of time to charge two cells each to a charge Q (mAh), no matter if you charge them simultaneously or one after the other. Because if you charge them simultaneously you can only supply I/2 each.

"Tesla offers free electricity to most of its Model S and Model X customers while paying almost $1 per kilowatt hour to produce it, Morsy said. That amounts to a subsidy of as much as $1,000 per car in 2017."

I realize that most people believe that Tesla and Uber will be able to continue subsidising their operations indefinitely, but it makes me very nervous.

I can't take this author seriously. There is no way that Tesla is paying $1/kw. That is way past the retail rate, and I bet that they are paying much less than the retail rate in many of their markets.

Yeah, that's definitely bullshit, esp considering residential power in the PNW is $0.07/kWh.

Residential power is often cheaper than commercial (at least, small scale) in practice. One reason is that commercial folks pay surcharges for power factor.

For example, in San Jose, CA, the average residential is ~$0.156/kwh

Commercial is $0.1408/kwh [1].

If you operate at a 90% power factor, and are surcharged the other 10%, ...

[1] https://www.electricitylocal.com/states/california/san-jose/

But yeah, at Tesla's scale, it should not be $1/kw.

I could believe that to be the all-in cost for a supercharger or something weird like that.

Because they should be paying close to the industrial rate, if not lower.

Nope. Electricity for residential use costs more than electricity for commercial use, which costs more than electricity for industrial use. A fast-charging truck stop is most similar to industrial use, since it involves a lot of power at a single location, and probably also can give the utility at least a few minutes warning before ramping up to full power. From the Energy Information Administration: https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

Not only does Tesla negotiate their electrical rate, they use PowerPacks at several supercharger sites to shave peak load to reduce and/or eliminate demand charges.

They would if they were pulling straight from the grid. Go to your power company and ask how much it would cost to surge a mega watt of power at peak times. Those kinds of surges are really expensive to handle. Of course Tesla uses storage and solar to smooth their demand so that they can pay normal rates.

$1/kwh is a joke price. Peaking natural gas plants run at 20 cents/kwh on the high end. You can go buy a honda gas generator from home depot and run it for 1-2k hours and pay less than that per kwh.

I get your point, and you are probably right somewhere in the country. Having said that, we have industrial plants around here with similar issues, and I'm confident that the rates that they pay are vastly lower than even the $0.07/kwh that Tesla is talking about.

$1/kwh is an extreme outlier and essentially pointless to talk about. There are lots of other options at that price point.

I am shocked to see this number. It seems insanely high. Is it really possible they pay anywhere near that for electricity?

Perhaps it includes a portion of the capital cost for the chargers along with the associated operational costs?

That must be the case, but we don't know what numbers they used to come to this cost. The number was just thrown out there without anything backing it up and is an order of magnitude off from what would be expected.

I do not believe this is true at all. A lot of people do not supercharge their car often because it is super inconvenient. You need to wait at least 30 minutes to get over 50% charge. One of the great things about electric cars is that you can charge them at home just like your phone and never need to worry about “do I need to fill up to get to work?” You only need super charger when you are on road trips. So most people use superchargers only once or twice a year.

According to /r/teslamotors this perk is worth less then $1000 for the total lifespan of the car for most users (there are a few taxis which use significantly more but not normal users). This is not a lot of money considering the car starts at $70k, can easily go up to $120k and maxes out at about $260k.

Edit: the price per kWh is also wrong. Tesla currently sells electricity for an average of 20¢ kWh to consumers which do not qualify for the free super charging perk and they have said they will sell it for 7¢ to semi truck customers. So we can assume Tesla pays between 5¢ and 15¢, depending on the location and whether they have solar and powerpacks installed.

Supercharging for free is really a gimmick and free advertising for them because a lot of people who buy such expensive cars value their time above what it takes to recharge it every week. The only reason Tesla built supercharger is because they wanted to enable long distance travel for electric cars.

Ya, my home bill is 13 cents per kwh. I can't figure out why it would cost Tesla $1.

As for the super chargers, I'm pretty sure you can no longer use a supercharger for free if you live nearby it. You are only allowed free usage when travelling.

As for the solar panels on the charging station, that sounds almost useless. Like putting a little solar panel on the sunroof of your model s.

The quote is wrong.

First of all, supercharging was never 'Free' - it was a $1,000 addon option (at purchase, or $2,000 later) for a long while before finally being made standard. (The hardware was integrated into all models shortly after launch, but cost money to activate)

Secondly, they killed the unlimited free charging program for new cars as of this year. (April, I believe was the cutoff for delivery of vehicles with unlimited supercharging)

The motivation for killing the unlimited free charging program seems to be partly people who would never charge at home, instead always charging at superchargers and often leaving cars parked for hours in busy locations, and the increasing commercial use of the supercharging network (by taxi companies).

How much does it cost to use now?

I got a new Model S in October and it came with free supercharging for life, because I had a referral code from another Tesla owner.

Given Tesla's recent experience in building the South Australian battery bank, I wonder if it is possible to build something similar at a truck stop.

Imagine a 10MWh battery pack that constantly charges from the grid, when a truck pulls in it can dump charge into the truck at a high rate.

I was thinking about diesel which is trucked in to the truckstop and stored in tanks, and then pumped out when needed. This would store charge in batteries and then pump it out when needed.

> To meet Tesla’s claim of 400 miles in 30 minutes for a semi carrying 80,000 pounds would require its new Megachargers to achieve output of more than 1200 kW

1200 kw is a lot of power. That's the average amount of power used by 600 homes, or half of the output of a large wind turbine here in the Midwest, to charge a single truck.

If they use a 440 V supply to charge it, that'd be over 2700 amps.

Eh, there's 20 120kW stalls in the Centralia Supercharger so while it's a lot I don't think it's crazy-talk.

That requires a really big plug. Like this one, 400 amps at 440VAC, three phase.[1] There's a standard plug for plugging large ships into shore power. Truck stops are going to need high tension lines coming in.

[1] http://www.cooperindustries.com/content/public/en/wiring_dev...

I wonder if they might do some sort of powerwall setup where they install a battery bank at the truck stop that can supply the power, it gets charged off the grid constantly, periodically trucks come in and suck big chunks of power out of it.

Sounds like their existing chargers are already 480V. [https://en.wikipedia.org/wiki/Tesla_Supercharger]

I might have been skeptical too but I recently saw a _ship_ charged while docked for about 50min in Norway. Big plugs, two circuits and I think 600V. I took a picture that I could dig out for the curious.

Wow I would love to see that!

Am I reading this right? A electric ship?

Working on a ship without power is like working in a basement during a blackout. Either you hook up to shorepower or you keep your genset running and everyone else near the dock has to deal with the smoke and noise.

No, a normal ship. To minimize pollution, most ports now require cargo ships to run their electrical systems off of harbor power while docked (instead of using the ship's own diesel generators).

This one is in the works: https://qz.com/980207/a-self-driving-electric-ship-will-repl...

Although it is very good to be skeptical, it makes the article less valuable than it could have been. 'Musk claimed X and people we talked to said they don't know how it's possible.' I am not saying that the people they consulted didn't know how, but using just that for the entire article was unnecessary. They also claim battery density is increasing by Y% and maybe Tesla is banking on that. Well those density increases because someone somewhere is finding ways to do it. It's not happening by some magic. Maybe Tesla found some ways to improve it? Why do they have to rely on someone else?

Maybe I am being too critical of the article and I understand that author too can do very little but speculate. But maybe consult variety of people rather than just 'I don't know how so it must not be possible' people.

Edit: is there a way for tesla to purchase electricity for solar city customers or something and direct it to charging stations? Or is that now how it all works?

They could have easily added a few more people speaking while they were at it: https://asia.nikkei.com/Tech-Science/Tech/New-battery-techno...

Very good supplement information. I didn't realize Li ion batteries were so close to their theoretical limit.

While I see some crazy talk in that article, I'm actually pleased with the idea of getting the point across that this requires technical advances.

So many people just nonchalantaly act like they just tossed a few more 18650s in there that it is nice to see someone point out how improbable that is. I'm really looking forward to hearing how this is actually happening.

> Musk’s claim that the truck will be able to accumulate 400 miles of charge in 30 minutes would allow the Semi to achieve the first true long-haul ranges in the industry. A driver might start the day with 500 miles of range, top off the battery at lunch, and be able to complete driving the U.S. legal limit of 11 hours in a day with range to spare. But doing so would require a charger unlike anything seen before.

Stupid question: Why is it no option to simply hot-swap the battery? (Possibly with mechanical assistance)

If you're already talking about a scenario where the charging happens at motels or gas stations, it seems easiest to have a stock of batteries that you can charge over longer time and swap them out whever a truck comes in.

This is more of an economic / business problem than a technical one.

Just who do you think would be the owner of the replacement battery packs?

If your answer is Tesla, then you've made huge and IMHO unrealistic assumptions about Tesla's capital allocations.

If you expect haulage companies to buy and charge batteries around their most likely needed locations then you are even further off. In nearly every case, their business demands extreme routing flexibility.

Estimates for the weight of the battery put it at like 10,000-20,000 pounds, and it's a 120,000 dollar battery. Who's going to maintain a million-dollar battery stock? You'd need liability insurance and equipment out the ass to deal with batteries that large. That's not a procedure you'd easily get done in 30 minutes. Charging the dang thing is a way better model.

It breaks the "laws of batteries" until it doesn't. Has everyone lost their memory retention? Maybe everyone on HN is Software centric and hardware hobbyist. Fair enough. Big things coming in the battery space. https://news.utexas.edu/2017/02/28/goodenough-introduces-new...

Can't you just have multiple super-chargers charging different banks of batteries in parallel?

Not sure why this is getting downvotes, it seems like a blindingly obvious part of the system. As for power to the chargers and paying high premiums for surge loads, it's a real shame there's no technology that Tesla could use to accumulate and store power locally at stations with local storage capacity determined based on expected usage.

For that matter, just take the flat frame/battery pack of the current cars and make them replaceable slabs on rails. Charge each one independently or swap them out, though that'd probably be a service thing instead since you probably want to keep those trucks on the road as much as possible.

Yes, but only if you understand how electricity works. And indeed, rapid parallel recharging is required for the regenerative braking system whilst burning up the Autobahn in Ludicrous Mode. The motors can throw up to 1600 amps while braking and the batteries can soak it all up...until thermal limits are hit and then the mechanical brakes have to kick in.

Apparently the Bloomberg “expert” doesn’t grasp basic electric principles like wiring in parallel.

Bloomberg trying to manipulate the stock price? Could it be?

It's an informative article, but the title is inaccurate. Tesla seems to be relying on plausible extrapolations for batteries in ~2020.

Bingo. Not only that, but they may even rely on battery extrapolations for 2022, despite the truck and car being launched in 2019-2020. All they need is to break-even in the first year or two, and then they can make-up the profits from the improvement in battery prices. That said, the roadster itself will likely be profitable from day one. It's the truck that may not be.

This is why Musk keeps getting ahead of everyone else and leaves carmakers and media writers in "shock and awe" - because he keeps thinking outside of the box, while they keep thinking within the existing or past constraints.

Meh, I think other companies just don't have the bravoure a man like Musk has. Also it helps if your company is a start-up and no heads will roll if you don't make a profit. Established companies don't have that luxury.

Established companies keep their stock price high by being conservative. Startups/growth companies keep their stock price high by pushing the envelope.

You don’t need bravoure to do math.

And if there's anyone who has good estimations to extrapolate the price and density development of batteries, it's the company that's building the world's biggest battery factory in close collaboration with one of the world's foremost battery manufacturers.

If there should be a remote chance that Tesla is able to sell a product in 2019/2020 based on new battery technology, they must already have preproduction cells in testing right now. 2 years is very close just to put something into production. So the prototypes shown must have at least the basics sorted out alread.

The “laws of batteries”?

That seems to mean current battery performance.

“Every time the global supply of batteries doubled, prices drop 19%”

“Every year the energy density of batteries increases by about 7.5%”

So, in 10 years electric cars will double their range, which should be more than enough for most people.

We should be careful with apply Moore's Law style of thinking when it comes to battery innovation. These things can and will hit hard limits at some point. Real progress can be much slower and much less predictable than in the semiconductor industry.

The funny thing is that it really hasn't been that much less predictable. Progress has been slow but steady and Tesla's business model has been built around largely predictable technological progress.

7.5%/year is probably an overestimate, though, and you are right that at some point it will hit diminishing returns. Moore's law has too, though, eh?

The correct term is “disrupt”.

> based on Bloomberg's estimates

Oh, good. I thought they were going to bring in a battery expert to disprove the battery experts that work for the company who, according to Bloomberg, has the most advanced charging systems on the market. Whew! Dodged a bullet, there.

I think most people are in agreement that the lithium ion battery is less-than-ideal technology that's due for replacement. And we have a number of innovations in battery technology vying for the opportunity.

It's starting to feel a bit like Tesla's massive investments are only serving to further entrench the existing battery model. He's basically working to replace Big Oil with Big Lithium. There's no denying the benefits of breaking our addiction to fossil fuels, but we need to be mindful of the obstacles to tomorrow's progress we're erecting in the name of today's.

> And we have a number of innovations in battery technology vying for the opportunity.

No, we don't. We have lots of news articles about amazing breakthroughs and absolutely nothing in actual production.

> It's starting to feel a bit like Tesla's massive investments are only serving to further entrench the existing battery model.

If you can come up with a battery chemistry that outperforms lithium ion, there will be nothing stopping the absolutely massive torrential downpour of money on top of you. Batteries are used everywhere, not just in cars. A new chemistry that works well would be huge. The problem is that there's lots of hype and marginal results when it comes to new battery tech.

> He's basically working to replace Big Oil with Big Lithium.

Electric cars need X kg of elemental lithium over the lifetime of the car. ICE cars need [on the order of] X kg of gasoline every 200 miles. This makes such a huge quantitative difference that comparing lithium mining to oil mining is almost pointless.

In addition, lithium can in principle be recycled when the battery wears out. Gasoline cannot be recycled, even in principle.

Some CO2 hydrogenation processes can produce liquid fuels which is kind of like recycling gasoline, but this is much more complicated than recycling batteries. It may still prove useful for fueling rockets or aircraft in a CO2 neutral way.

Understood. My former employer was researching this. But taking the separated atoms of gasoline and rebuilding hydrocarbon molecules from them is -- as you say -- not quite the same thing as recycling. And it requires very large energy inputs. It only really makes sense for aircraft fuel, since large or high-performance aircraft cannot (yet) be powered by batteries.

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