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

81–90 of 284 posts

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

#81

Post by earl »

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…

since I was unaware:

Tesla S seems to practically cost (with the large battery that still only gets you 300 miles) $70K after a $7.5k tax credit [1] and the Nissan leaf costs $35K but that seems to be before the $7.5k tax credit.

[1] http://www.teslamotors.com/models/options

[2] http://www.nissanusa.com/leaf-electric-car/index#/leaf-elect...

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

#83

Post by noonespecial »

URSpider94 wrote: post #61

A lot of people have picked at the "it won't charge through a 100-foot extension cord" statement. While I have no idea if this particular statement is true or not, it certainly wouldn't be unexpected behavior for a power management system. Modern charging and power conversion systems are designed to operate under specific use cases. When the Tesla charger first sees line voltage, it likely does some quick testing to…

This is a good point, but to use the iPad as an example, "not charging" actually does in most cases charge very slowly. It takes what it can and provided its in standby, this is usually enough to ever so slightly charge. In the on position, it will discharge more slowly than battery alone.

The point is "optimal charge" or "complete destruction of the battery without warning" might not be the only two, or best choices available. "The best we can do with 500 watts" might be a better choice.

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

#85

Post by bri3d »

wisty wrote: post #66
URSpider94 wrote: post #49

Earlier quoted context omitted.

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? Not necessarily. This might help, but the battery will also have self-discharge, meaning that it can lose charge without being connected to any load at all. If you get the charge down low enough, and then wait long enough, then even a full disconnect from the system w…

You could add a $100 mobile phone, which auto-calls a service center. If 1% of cars get "bricked", that's $10,000 per car saved, not including intervention costs. Even with some false positives, it would be worth it. Of course, that cost is carried by Tesla, not the customer. "The Tesla manager called me to warn that my car was in trouble" is a much better customer experience than "my Tesla broke down, and cost $40k…

That's exactly what Tesla do, even once having gone so far as tracking the car down via GPS and charging it themselves when the owner was unresponsive.

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

#86

Post by prostoalex »

earl wrote: post #81
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…

since I was unaware: Tesla S seems to practically cost (with the large battery that still only gets you 300 miles) $70K after a $7.5k tax credit [1] and the Nissan leaf costs $35K but that seems to be before the $7.5k tax credit. [1] http://www.teslamotors.com/models/options [2] http://www.nissanusa.com/leaf-electric-car/index#/leaf-elect...

Correct, on the page you linked there's a 'view pricing details' link at the bottom.

For base model it's $27,700 net value*, after tax savings; starting at MSRP $35,200, with federal tax savings from 0 to $7,500.

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

#87

Post by huhtenberg »

Let me tell you how to brick a top of the line 2009 BMW.

Easy-peasy. Lots of small trips, under 5 km, for 9 months. That's it. Apparently the discharge caused by starting the car and a draw from all the packages that are strapped to it are not offset by the charge received while driving unless the distance is at least 10 km per engine start. The only warning that the car gives is an "excessive battery discharge" and when it pops up the battery can no longer be fully recharged. Not covered by the warranty, because apparently there's a one-liner in manual that says "20 minute a day continuous drive minimum". Unlike Tesla's though the battery is "only" $700 to replace, not $40k.

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

#88

Post by throwaway64 »

fleitz wrote: post #6
powertower wrote: post #3

What's the issue with the battery tech that makes it not chargable after a full discharge?

It's inherent to any lithium ion battery design which is why every laptop, iphone, etc that uses a lithium ion battery has circuitry that cuts power when the batter reaches 1% to 5% it can occur in your laptop if you discharge the battery entirely and then leave your battery uncharged for months (or less if stored cold). Some kind of chemical change occurs in Li batteries when completely discharged.

storing hot is what is detremental to lithium batteries, storing them cold increases lifetime

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

#89

Post by rdl »

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 get an Audi S5 or S7, so you are taking a 25mpg or less car off the road for an incremental cost of $30k. For me, the carpool benefits make it worthwhile alone (I wasted 1.5h driving to SF today, which would have been 30min in the carpool lane, but I only had one rather than 2 companions).

Making big trucks, SUVs, etc fuel efficient IS the low hanging fruit, followed by cars like taxis and police cars which drive lots of miles and idle a lot. Taking a 50mpg city car to 100mpg, driven 5 miles a day, isn't much savings by comparison.

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

#90

Post by nash »

jws wrote: post #33
noonespecial wrote: post #26

Earlier quoted context omitted.

120v @ 15A is 1800 watts. As I said, I was able to measure the wattage being delivered at the end of my 100 foot 16 gauge "home depot" orange extension cord connected to a space heater and found less than 900 watts being delivered to a load that normally pulls 1750. The voltage had also dropped below 100 volts. Its possible that the Tesla simply won't charge at all if the current or voltage on the line becomes too lo…

The pack is 53kWh according to wikipedia and discharges in 11 weeks from full according to the article. Unless I botched a decimal place, that is a 29 watt idle load. (53000 watt hours / (11 weeks * 7 days/week * 24 hours/day) ). In perspective, that is about the same as 4 night lights. Clearly there is about 20 times that much power available at the end of a 100 foot extension cord in a standard household outlet. Fa…

You forgot "Owner made up story"
Post reply on HN