Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

"It's A Brick" - Tesla Motors' Devastating Design Problem

theunderstatement.com

Post reply on HN
Print view View original

151–160 of 284 posts

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#151

Post by rrrazdan »

schiffern wrote: post #142
modeless wrote: post #7

Earlier quoted context omitted.

Batteries self-discharge, even when disconnected. 5% is probably not enough to last months, especially if the car is exposed to high temperatures.

I would be amazed if Tesla Motors was running that pack at 90% depth of discharge. 80% is far more typical. The other thing to consider is that as the voltage drops, so does the leakage current. Really, this whole thing could be solved by putting a tiny solar panel on the back dash.

Which is what the Nissan Leaf does(pretty nifty idea, I'd say). But its not really a solution in the sense that it wouldn't work for cars parked inside.

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#152

Post by zvrba »

Tesla uses apparently Li-ion battery. I wonder why I han't experienced the same problem with other electronics using that same type of battery. For example, I had my fully-charged mobile stored away for approx 5 months without charging. When I needed it again, the battery was still usable.

A side-question: can somebody explain what happens to a Li-ion battery when it fully discharges? Why does it become a "brick"?

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#153

Post by salem »

bane wrote: post #144
jdietrich wrote: post #75

Tesla are a sideshow and we desperately need to stop talking about them, because they're harming efforts to improve energy efficiency. Nissan are now in full production of the Leaf, a practical electric car that's half the price of the Model S. Renault have the Fluence ZE on sale in Israel and ready to go internationally this year. Mitsubishi are selling the i-MiEV in quantity in Hong Kong and Japan. All of these big…

I think you and Tesla are not having the same conversation. They are doing it The Wrong Way if the conversation is efficient commuter/city cars. But tanks are doing it The Wrong Way if you're talking about space launch vehicles too. Tesla doesn't market or really care about efficiency -- and Tesla buyers don't really care about efficiency (or at least not as their #1 priority, if they did there are plenty of high eff…

Exactly right. To get that performance from a gas powered car would not only cost a lot more than a tesla, but you'd easily drop $40k of value on the car by driving it out of the lot, let alone by killing the battery.

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#154

Post by salem »

rdl wrote: post #89
jdietrich wrote: post #75

Tesla are a sideshow and we desperately need to stop talking about them, because they're harming efforts to improve energy efficiency. Nissan are now in full production of the Leaf, a practical electric car that's half the price of the Model S. Renault have the Fluence ZE on sale in Israel and ready to go internationally this year. Mitsubishi are selling the i-MiEV in quantity in Hong Kong and Japan. All of these big…

I disagree. Based on time in a Roadster, and what I've seen of the model s, I would be totally happy with the S in the bay area, and either rent or keep a second car for trips out of the bay. With a constant level of tech, sure, the city car makes more sense, but assuming you can afford the high tech batteries, the tesla seems like a great car for how Americans use cars. If I weren't getting a model s, I'd probably g…

Regarding the taxis, just about every taxi in Australia runs on LNG these days. It's widely available, and aside from the benefits on somewhat cleaner emissions, you can easily make the money back on the conversion for the number miles they rack up. I'm surprised this is not subsidized in the USA, especially now that the reserves of gas have been revised up so much.

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#155

Post by CaptainZapp »

cynicalkane wrote: post #131
pclark wrote: post #100

My confusion with Tesla is this: around the rest of the world - outside of USA - there are already very fuel efficient automobiles. 60, 80, even 90 miles per gallon are common and applauded in Europe. America has the opposite approach and appears to optimise for size, comfort and perceived safety. (SUVs, Trucks, large saloons.) None of the things American consumers appear to value are correlated in the Tesla. When I…

Euro testing cycles are more generous, MPG figures are quoted in Imperial gallons (which are larger), and probably because of less dense cities they tend to be more tolerant of smog belching diesels. Diesels are fuel efficient but it's expensive to make them pollution efficient enough to pass American regulations. Many cars are the same in both countries. There isn't anything about America that makes them less effici…

  Euro testing cycles are more generous, MPG figures are quoted in Imperial gallons
I have never seen a MPG notation anywhere in Europe (possibly in the UK, but certainly nowhere else).

Car efficiency is quoted by liters / 100 km just about everywhere around here.

Or am I missing something?

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#156

Post by theDaveB »

pkulak wrote: post #136
modeless wrote: post #7

Earlier quoted context omitted.

Batteries self-discharge, even when disconnected. 5% is probably not enough to last months, especially if the car is exposed to high temperatures.

So will my laptop "brick" also if I don't plug it in for a couple weeks?

I left my MacBook on but the lid closed and went on a weeks holiday (not sure how much charge the battery had) when I come back it was dead and now will not take a charge.

As its £90 for a new one, I just leave it plugged into the wall now.

Dave

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#157

Post by TeMPOraL »

haberman wrote: post #134
jdietrich wrote: post #75

Tesla are a sideshow and we desperately need to stop talking about them, because they're harming efforts to improve energy efficiency. Nissan are now in full production of the Leaf, a practical electric car that's half the price of the Model S. Renault have the Fluence ZE on sale in Israel and ready to go internationally this year. Mitsubishi are selling the i-MiEV in quantity in Hong Kong and Japan. All of these big…

Who said that electric cars have to be about energy efficiency? To me the primary reason to move to electric are to ditch petroleum and its associated problems (pollution, oil spills, foreign energy dependence). The way to the future is to convince people that new technology is better for them. If the message instead is "you need to give up things you like for the greater good," people will oppose you at every move,…

> The way to the future is to convince people that new technology is better for them. If the message instead is "you need to give up things you like for the greater good," people will oppose you at every move, and rightly so;

While I agree in principle, ...

> do you really want to live in a world where computer screens are just barely bright enough to see, where buildings are sweltering on hot days, freezing on cold days, showers are cold, and the speed limit is never higher than 55mph?

Alternative is unfortunately having no computers, no air conditioning and no cars at all. Current energy consumption is too high to sustain even if we go all electric and switch to nuclear + renewables[1]. We need to think about energy efficiency at least a little bit more than we do now.

[1] - this book works out all the numbers: http://www.inference.phy.cam.ac.uk/withouthotair/

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#158

Post by regularfry »

spenceyboi wrote: post #117
jdietrich wrote: post #75

Tesla are a sideshow and we desperately need to stop talking about them, because they're harming efforts to improve energy efficiency. Nissan are now in full production of the Leaf, a practical electric car that's half the price of the Model S. Renault have the Fluence ZE on sale in Israel and ready to go internationally this year. Mitsubishi are selling the i-MiEV in quantity in Hong Kong and Japan. All of these big…

How is Tesla trying to engineer around culture? If anything, they are engineering for our culture that is fascinated with high speed performance cars(Lamborghinis and Ferraris an example) and luxury cars(Bentleys and Lexus an example). Their models are giving what the customer wants. An electric car that is still fashionable in today's taste of cars. Of course the early models will have a few problems, but their wide…

Automotive PR departments have been engineering around culture for decades - why do you think you associate "luxury" with Bentley and especially Lexus?

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#159

Post by CamperBob »

noonespecial wrote: post #5

Could this really not be prevented by a $10 microcontroller and a big-ass relay to just disconnect the battery if it reaches a certain discharge state? Even my iPhone can turn turtle to protect its battery when it gets too low. Also how much power does it take to keep the damn thing plugged in? The article indicates that a 100 foot extension cord isn't enough just to break even and the car discharges even when plugge…

Perhaps the most straightforward fix would be to simply refrain from drawing any current at all from the vehicle's main battery while parked. The alarm and any other standby processes should run from a 12-volt motorcycle battery or something, which is recharged during driving, and can be jumped like any other car battery if allowed to go dead.

That wouldn't fix the Li-ion self-discharge problem completely, but it could provide as much as a few months' worth of margin.

In any case it's batshit insane to leave early adopters stuck with a $40,000 bill for your lack of engineering foresight. That was the real surprise in the article.

Re: "It's A Brick" - Tesla Motors' Devastating Design Problem

#160

Post by schiffern »

rrrazdan wrote: post #151
schiffern wrote: post #142

Earlier quoted context omitted.

I would be amazed if Tesla Motors was running that pack at 90% depth of discharge. 80% is far more typical. The other thing to consider is that as the voltage drops, so does the leakage current. Really, this whole thing could be solved by putting a tiny solar panel on the back dash.

Which is what the Nissan Leaf does(pretty nifty idea, I'd say). But its not really a solution in the sense that it wouldn't work for cars parked inside.

If it's parked inside, generally either A) you have a plug, or B) it's artificially lit 24/7. That should be enough to compensate for leakage current.
Post reply on HN