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

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?<p>Here are current industrial&#x2F;transportation&#x2F;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&#x27;t believe Bloomberg published this article. Not to mention a huge amount of charging can happen overnight when drivers are sleeping and electricity prices&#x2F;demand are super low.<p>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.<p>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&#x2F;business majors doing technology writing larping like they know the difference between a watt and an amp.<p>[0]<a href="https:&#x2F;&#x2F;www.eia.gov&#x2F;electricity&#x2F;monthly&#x2F;epm_table_grapher.php?t=epmt_5_6_a" rel="nofollow">https:&#x2F;&#x2F;www.eia.gov&#x2F;electricity&#x2F;monthly&#x2F;epm_table_grapher.ph...</a>

If this were any other company making such unsubstantiated claims that didn&#x27;t have any basis in the reality of the underlying technology, they&#x27;d be getting roasted here.

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?

&quot;<i>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>&quot;<p>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.

Given Tesla&#x27;s recent experience in building the South Australian battery bank, I wonder if it is possible to build something similar at a truck stop.<p>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.<p>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.

&gt; 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<p>1200 kw is a lot of power. That&#x27;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.<p>If they use a 440 V supply to charge it, that&#x27;d be over 2700 amps.

Although it is very good to be skeptical, it makes the article less valuable than it could have been. &#x27;Musk claimed X and people we talked to said they don&#x27;t know how it&#x27;s possible.&#x27; I am not saying that the people they consulted didn&#x27;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&#x27;s not happening by some magic. Maybe Tesla found some ways to improve it? Why do they have to rely on someone else?<p>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 &#x27;I don&#x27;t know how so it must not be possible&#x27; people.<p>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?

&gt; <i>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.</i><p>Stupid question: Why is it no option to simply hot-swap the battery? (Possibly with mechanical assistance)<p>If you&#x27;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.

It breaks the &quot;laws of batteries&quot; until it doesn&#x27;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. <a href="https:&#x2F;&#x2F;news.utexas.edu&#x2F;2017&#x2F;02&#x2F;28&#x2F;goodenough-introduces-new-battery-technology" rel="nofollow">https:&#x2F;&#x2F;news.utexas.edu&#x2F;2017&#x2F;02&#x2F;28&#x2F;goodenough-introduces-new...</a>

Can&#x27;t you just have multiple super-chargers charging different banks of batteries in parallel?

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

It&#x27;s an informative article, but the title is inaccurate. Tesla seems to be relying on plausible extrapolations for batteries in ~2020.

The “laws of batteries”?

The correct term is “disrupt”.

&gt; based on Bloomberg&#x27;s estimates<p>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&#x27;s due for replacement. And we have a number of innovations in battery technology vying for the opportunity.<p>It&#x27;s starting to feel a bit like Tesla&#x27;s massive investments are only serving to further entrench the existing battery model. He&#x27;s basically working to replace Big Oil with Big Lithium. There&#x27;s no denying the benefits of breaking our addiction to fossil fuels, but we need to be mindful of the obstacles to tomorrow&#x27;s progress we&#x27;re erecting in the name of today&#x27;s.