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Why Tesla Cars Aren't Bricked By Failing Batteries

samzenpus posted about 2 years ago | from the not-do-fast-now dept.

Power 362

itwbennett writes "Don't believe recent claims made by a blogger that non-functioning batteries in the Tesla Roadster cause the electric cars to be bricked, says IDC analyst Sam Jaffe. 'Here's the primary fact that the blogger in question doesn't understand: the Tesla battery pack is not a battery,' says Jaffe. 'It's a collection of more than 8,000 individual batteries. Each of those cells is independently managed. So there's only two ways for the entire battery pack to fail. The first is if all 8,000 cells individually fail (highly unlikely except in the case of something catastrophic like a fire). The second failure mechanism is if the battery management system tells the pack to shut down because it has detected a dangerous situation, such as an extremely low depth of discharge. If that's the case, all that needs to be done is to tow the vehicle to a charger, recharge the batteries and then reboot the battery management system. This is the most likely explanation for the five 'bricks' that the blogger claims to have heard about.'"

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battery vs cell (5, Insightful)

Anonymous Coward | about 2 years ago | (#39134907)

There seems to be a fundamental misunderstanding of the terms 'battery' and 'cell'. A battery is the collection of cells. So a Tesla could be bricked by a failed battery but it is tolerant to a failure of individual cells. This is not surprising.

Re:battery vs cell (5, Informative)

L4t3r4lu5 (1216702) | about 2 years ago | (#39135157)

I would have to assume that a Tesla wouldn't be "bricked" by a failed battery either, as the batteries are presumably replaceable by the manufacturer.

Remember: Bricked = Failed and unrepairable.

Re:battery vs cell (0, Troll)

furytrader (1512517) | about 2 years ago | (#39135335)

So Bricked = failed and unrepairable ... which is why Tesla requires owners to shell out $40,000 to REPLACE a completely discharged battery. The funny thing here is that the Nissan Leaf and Chevy Volt were both designed specifically to avoid this type of thing - you'd think someone asking you to shell out over $100,000 for a car would've been smart enough to think of that too.

Re:battery vs cell (5, Insightful)

BasilBrush (643681) | about 2 years ago | (#39135445)

which is why Tesla requires owners to shell out $40,000 to REPLACE a completely discharged battery.

It's bunk. If the battery pack is completely discharges, tow it to a charger, plug it in and wait. Then reset the battery management system, and you;re good to go.

What kind of cretin believes that a discharged rechargeable battery requires replacement?

Re:battery vs cell (5, Insightful)

fuzzyfuzzyfungus (1223518) | about 2 years ago | (#39135535)

It depends on what you mean by 'discharged'. Some battery chemistries do, indeed, die(or at least suffer severe capacity damage) if 'discharged' in the sense of 'take a bare cell, connect to a resistor of suitable value until current drops to zero'. The high performance lithium cell chemistries certainly are rather touchy, and even humbled old lead-acid will start to sulfate if left discharged like that for any length of time... However, because that is a trivially bad thing, such batteries are hidden behind a management circuit that will delclare the battery 'discharged' and refuse to provide any further output well before the physically destructive discharge level is hit.

If Tesla actually built multi-kilodollar battery packs that allow their cells to run below safe discharge levels, somebody at Tesla needs a beating. If, however, this story is 'rechargable battery pack must be recharged and possibly recalibrated after running 'flat' as defined by the management circuit!', then the writer needs a beating.

Re:battery vs cell (3, Informative)

Skapare (16644) | about 2 years ago | (#39135667)

Once the bank of cells does go below the detection level, it is still possible for them to still discharge further, depending on the condition. But they should wire the battery pack management system in such a way that it can be powered itself by other means than just the battery pack it manages. When the charge connection is plugged in, it should be made so that a low level of power is provided to bring the management system up without it being powered from the pack. At this point, it should be able to test the battery pack condition to determine if it can be charged back up safely or not. If Tesla didn't think of it, their bad.

Re:battery vs cell (0)

Anonymous Coward | about 2 years ago | (#39135563)

Duracell

Re:battery vs cell (3, Interesting)

robbak (775424) | about 2 years ago | (#39135473)

Teslas are also designed to avoid deep discharge: read the article! You would have to discharge it and then leave it parked for months to damage enough cells of the battery, but that would be yoru fault.

Yes to this (0)

UltraBadger (2580929) | about 2 years ago | (#39135187)

Yes, yes, to the AC you listen.

Re:battery vs cell (2)

mastermind7373 (1932626) | about 2 years ago | (#39135227)

Maybe the setup consists of 8000 batteries, each battery containing several cells.

Re:battery vs cell (1, Insightful)

Tsingi (870990) | about 2 years ago | (#39135265)

There seems to be a fundamental misunderstanding of the terms 'battery' and 'cell'. A battery is the collection of cells. So a Tesla could be bricked by a failed battery but it is tolerant to a failure of individual cells. This is not surprising.

Semantics.

Statements like that one are what this piece is about. AC either hasn't read the article or is a troll. This is exactly what it explains can't happen, and statements like the one the AC made are the kind of propaganda that the misinformation campaign spreads.

Re:battery vs cell (5, Informative)

DerekLyons (302214) | about 2 years ago | (#39135629)

There seems to be a fundamental misunderstanding of the terms 'battery' and 'cell'. A battery is the collection of cells. So a Tesla could be bricked by a failed battery but it is tolerant to a failure of individual cells. This is not surprising.

Semantics.

No, not semantics, but rather proper use of terminology. The AC is correct - a battery [reference.com] is a collection of cells. A battery pack is a collection of batteries. (The battery being the smallest individually replaceable part in the pack.)
 
That's why a "D" cell battery is called a "single cell battery" - because, duh, there's only a single cell in the battery. That's why automotive type batteries [wikipedia.org] (of the type you add water to) have multiple vent caps - because each individual cell must be separately vented and/or topped off with water.
 
The quoted IDC analyst adds to the confusion (at least to those of us versed in standard terminology) by using the terms battery and cell interchangeably, which is the same mistake often made by the general public - you for example.

Re:battery vs cell (5, Insightful)

geekmux (1040042) | about 2 years ago | (#39135319)

There seems to be a fundamental misunderstanding of the terms 'battery' and 'cell'. A battery is the collection of cells. So a Tesla could be bricked by a failed battery but it is tolerant to a failure of individual cells. This is not surprising.

There seems to be a fundamental misunderstanding of the terms 'brick' and 'won't start'. I know it's clearly far too late as I stare at a page of comments that look like "this" or 'this', but let's at least try and keep the IT geek terms out of the automotive industry, no matter how many "Intel Inside" bumper stickers you may run across.

Might I remind all of what has happened to the term "hacker" in mainstream media. I don't need or want to be labeled as a criminal for simply trying to get my damn car to start in the future, which is likely the more accurate terminology no matter what is under the hood. Mechanics probably have no idea why people keep talking about a "brick" either, for the automotive shop doesn't stock "mortar" for repairs.

Re:battery vs cell (1)

masternerdguy (2468142) | about 2 years ago | (#39135395)

Sssh! That isn't scary enough for news.

Re:battery vs cell (3, Insightful)

EasyTarget (43516) | about 2 years ago | (#39135397)

So a Tesla could be bricked by a failed battery but it is tolerant to a failure of individual cells.

No.. A Tesla cannot be bricked by a failed battery. It is merely a Tesla with a flat battery.. nothing more.

Terminology here is quite important, the negative word 'bricked' is being used to try and transfer a operator failure (running out of battery) into a criticism of the product itself.

Re:battery vs cell (3, Insightful)

masternerdguy (2468142) | about 2 years ago | (#39135577)

I suppose all electronics can be bricked by removing batteries then.

Re:battery vs cell (1)

BasilBrush (643681) | about 2 years ago | (#39135427)

CellBatteryBattery Pack.

The battery pack is tolerant to a failed cell or battery.

Re:battery vs cell (0)

Anonymous Coward | about 2 years ago | (#39135511)

There seems to be a fundamental misunderstanding of the terms 'battery' and 'cell'. A battery is the collection of cells. So a Tesla could be bricked by a failed battery but it is tolerant to a failure of individual cells. This is not surprising.

That's probably because it's not a strictly defined term. A collection of batteries is called a battery pack, which is what the Tesla has, and which is what the blogger is referring to when he says "battery".

The point of the article still stands, regardless of the lack of understanding on the part of both the blogger and the parent AC.

whew (5, Funny)

Anonymous Coward | about 2 years ago | (#39134919)

Good thing slashdot is here to help us debunk everything I'd never have heard about from random dipshit bloggers.

Re:whew (2)

Xest (935314) | about 2 years ago | (#39135291)

Yes, the real morale of the story is "Don't give a fuck what dipshit bloggers say". Going on to then debunk what they say publicly only feeds their blog views more and hence increases their ad revenue, which in turn makes it more profitable to be a random dipshit blogger talking utter shite.

Re:whew (0)

furytrader (1512517) | about 2 years ago | (#39135351)

Who is the dipshit blogger here? What has Tesla said to refute the claim that a completely discharged battery is not covered by warranty or that owners of the car have to shell out $40,000 to have the batteries replaced? The IDC Analyst says: "The first is if all 8,000 cells individually fail (highly unlikely except in the case of something catastrophic like a fire). The second failure mechanism is if the battery management system tells the pack to shut down because it has detected a dangerous situation, such as an extremely low depth of discharge. If that's the case, all that needs to be done is to tow the vehicle to a charger, recharge the batteries and then reboot the battery management system." If it's so easy to recharge the batteries, where does the $40,000 bill come from? Was the whistleblower hallucinating that?

Re:whew (2)

BasilBrush (643681) | about 2 years ago | (#39135451)

Was the whistleblower hallucinating that?

Many bloggers are full of shit. News at 11.

You really believe that a fully discharged rechargable battery needs replacement, just because a blogger said so? You're an idiot.

Re:whew (0)

Anonymous Coward | about 2 years ago | (#39135327)

A lot better than the other way round: Reporting the myth and fail to correct it when it's debunked. Unfortunately, that's how many newspapers work.

Tow? (3, Informative)

oniony (228405) | about 2 years ago | (#39134935)

>all that needs to be done is to tow the vehicle to a charger

Another claim was that the vehicles cannot be towed.

Re:Tow? (4, Interesting)

Jack Malmostoso (899729) | about 2 years ago | (#39135031)

Well technically towing an electric vehicle, missing a clutch, would make it a generator, which could possibly damage the battery. However there is a youtube video showing a Nissan Leaf being towed and the battery being recharged. Don't try this at home!

Another option with the Tesla could be to lift the back wheels and tow it with the front wheels on the ground, unless there is some regenerative braking system which still acts as a generator. And yes, you want to lock the wheels if you do that.

Re:Tow? (4, Funny)

Joce640k (829181) | about 2 years ago | (#39135113)

Just make sure you tow it backwards...

Re:Tow? (2)

ledow (319597) | about 2 years ago | (#39135123)

I'd be extremely disappointed (but not at all surprised) to find that a car manufacturer *HASN'T* considered how to tow an electric vehicle. I suppose they just expect people to know this and book a tow truck that picks the car off the road (but then - how do you get it onto that truck without a crane?).

I'd be less surprised if your average vehicle recovery firm wouldn't know about whatever-method and tow it anyway.

I also would be 100% completely unsurprised if most electric car owners have no knowledge of this whatsoever, even if it was written in the manual.

Re:Tow? (2)

newcastlejon (1483695) | about 2 years ago | (#39135201)

I don't think pulling a Tesla twenty feet from the roadside onto a flatbed truck is going to do a whole lot of damage. With that said, there are tow trucks that incorporate cranes to lift a vehicle bodily from the road; they're often used for parking enforcement. However, as you pointed out, a towing company would have to have such a truck and the wisdom to use it.

As for towing over distances with the front wheels lifted, that depends entirely on which axles the regenerative braking system operates.

Re:Tow? (0)

Anonymous Coward | about 2 years ago | (#39135597)

I suppose they just expect people to know this and book a tow truck that picks the car off the road (but then - how do you get it onto that truck without a crane?).

When you call for a tow truck, they ask you what make and model you have, and send the appropriate towing vehicle.

If you're doing it yourself, then it's your own damn fault if you fuck it up because you either didn't read or didn't understand what you were doing.

Re:Tow? (0)

Anonymous Coward | about 2 years ago | (#39135131)

Pretty sure there's a diode or two between the batteries and the motors. :-)

Re:Tow? (2)

uglyduckling (103926) | about 2 years ago | (#39135141)

I don't think that can be right. Otherwise, you would damage the car by switching off the engine at the top of a long, steep hill.

Re:Tow? (4, Informative)

Teancum (67324) | about 2 years ago | (#39135233)

However... the Tesla vehicles already take advantage of "becoming a generator" as that is part of the "regenerative braking system" used in the vehicle. That ability to "generate electricity" not only doesn't damage the battery, but it helps to recharge the system as well and is an intended behavior... at least if you are going downhill with a tailwind.

I've seen several electric vehicles that have a gasoline-powered "pusher" trailer that provides "emergency power" for long haul trips instead of looking for an outlet for the car. It isn't even that new of an idea for that matter.

Regardless, because of the simplicity of the drive train and that the engine is not an internal combustion engine, calling a dead Roadster "a brick" is going over the top even if you can't disengage the engine from the transmission. Yes, there is a transmission in a Roadster, and there was even going to be a "clutch", but that feature was removed due to the torque issues and other problems from the supplier that was originally going to provide the transmission (something that nearly killed the Roadster when it went into production).

The Roadster is a rear wheel drive vehicle, so I don't think the front wheels are connected to anything other than the steering mechanism. In that regard, it is more like a conventional automobile too. In other words, towing the car is just like towing any other vehicle when you don't have the keys to unlock the transmission from the drive train.

Re:Tow? (1)

mwvdlee (775178) | about 2 years ago | (#39135235)

Don't all electric vehicles recharge from the wheels already? It would be such a waste of energy when breaking, since you already have most of the hardware to utilize this energy.

Re:Tow? (0)

Anonymous Coward | about 2 years ago | (#39135311)

the Tesla roadster uses an induction motor, there are no permanent magnets so it cannot work as a generator unless you have external power

Re:Tow? (1)

AmiMoJo (196126) | about 2 years ago | (#39135401)

You assume that the batteries are connected directly to the wheels, but of course there is a battery management system that will prevent them from changing dangerously while being towed.

Re:Tow? (1)

ooloogi (313154) | about 2 years ago | (#39135209)

Around here, almost all tow trucks are tilt-tray: Just winch it on and drive off.

I doubt there'd be that many telsa vehicles in the backwater areas of the world that still tow vehicles with wheels on the ground.

Re:Tow? (3, Informative)

phoebus1553 (522577) | about 2 years ago | (#39135345)

Another claim was that the vehicles cannot be towed.

Maybe by a rope and your backwoods service jockey.

Winch it onto a flatbed, even locked wheels skid. Can't get to an end of it because it's parallel parked? There are these funny little things that scoop each wheel and then you basically push it sideways to wherever you CAN lift it. If you are towing something with AWD without a flatbed handy? Lift one end like anything else and use the wheel-scoop style things to jack the other end off the ground and tow it on them.

There are ways, and a good tow service knows them.

Re:Tow? (1)

BasilBrush (643681) | about 2 years ago | (#39135471)

Recovery vehicles that take the car completely off the road are not rare. And cost rather less than $40,000 to hire.

This IS a LiIon failure mode though (5, Interesting)

larwe (858929) | about 2 years ago | (#39134947)

It's a shortcoming of LiIon technology that if the cell becomes over-discharged, the cell may fail short circuit, and a subsequent recharge may cause an "exciting" failure (think flames). That's why all LiIon packs have a protection circuit that permanently disables the pack if it's discharged to the danger zone. Given the massive size of an automotive battery pack, it's easy to believe they have some very conservative safety devices in them. And it's also easy to believe that the cost of individually testing/replacing cells and "rebooting" the protection circuitry in a pack that has tripped its safety limits is prohibitive.

Re:This IS a LiIon failure mode though (1)

stereoroid (234317) | about 2 years ago | (#39135425)

OK. so my question is then: what does "bricked" mean, technically, in the Tesla battery case? If a protection circuit has kicked in and isolated the battery, then that should save the battery itself from permanent damage. The story is that Tesla is charging $40,000 for replacement of the complete battery pack, which suggests that a protection circuit has NOT saved the battery from permanent damage. Either that or the battery can be fixed and resold, and they're ripping off the customer. Those are the only possible explanations for a $40,000 bill, and neither look good.

Re:This IS a LiIon failure mode though (2, Insightful)

robbak (775424) | about 2 years ago | (#39135487)

How about this: the $40K has been made up from whole cloth by a blogger we already know is ignorant of the facts surrounding electric cars.

Re:This IS a LiIon failure mode though (1)

BasilBrush (643681) | about 2 years ago | (#39135497)

Those are the only possible explanations for a $40,000 bill, and neither look good.

The other explanation is that the blogger is full of shit. Apply Occam's Razor how you will...

Weak! (2, Interesting)

Anonymous Coward | about 2 years ago | (#39134951)

"The battery management system of the Tesla Roadster keeps the battery from being discharged to a damagingly low state of charge under normal driving conditions."

One of the original points was that if the car was left alone for a relatively short period of time then it would discharge fully due to physics, nothing the power management system can do about it.

This is a pathetically weak rebuttal to be honest. Take each one of his points and give us a counter-point to each one. So far it seems to be "He doesn't know what he is talking about, ner-ner!"

"Battery" (1)

Anonymous Coward | about 2 years ago | (#39134953)

Seriously? Why does someone who clearly doesn't know what a battery is (i.e. a collection of cells) writing about them? Oh, right, it's a "Blogger": Defined as someone who wishes they could be a journalist, but doesn't want to actually have to conform to any kind of standards or put forth much effort.

And I wish people would stop using "Bricked" to mean things it doesn't. If you can fix it by charging it, then by definition, it wasn't bricked! That's called "HAving a dead battery".

Re:"Battery" (0, Troll)

agentgonzo (1026204) | about 2 years ago | (#39135017)

'Bricked' is a term that originated with iPhones (failed jailbreaks etc). iPhone's are made by Apple therefore 'cool'. Ergo 'Bricked' is a cool term (by association). Therefore bloggers want to use it as much as possible (so they seem cool by association and 'with it'). Hence they use it as much as possible - even if they don't understand what it means and use it incorrectly. Much like the massive over-use of the word 'epic' nowadays to mean anything slightly-above-average.

Re:"Battery" (3, Informative)

Mitsoid (837831) | about 2 years ago | (#39135047)

Umm.. "Bricked" is a term for any phone that gets ... well.. "Bricked" as we call it..

It's been around since pre-iPhone.. phone modders have been unhappily bricking their phones for quiet a while to push it to its limits :-) iPhones, as usual, just made it "Popular"... the did not invent it.

Re:"Battery" (0)

agentgonzo (1026204) | about 2 years ago | (#39135105)

"It's been around since pre-iPhone"

Good to know - thanks. The first time I'd heard of the use of 'bricked' was with the iPhone, so I retract that part. The rest of my argument stands (in that bloggers have a propensity overuse terms that they don't understand just to sound cool and hip.

Re:"Battery" (1)

AK Marc (707885) | about 2 years ago | (#39135153)

I remember warnings with firmware for DSL modems and "bricking" back 10+ years before the iPhone existed. But yes, it's one of those things where nobody uses it right. "it's not a brick, you can open the case, pull the EEPROM chip, replace it with a new blank one, then re-flash the modem with new firmware and it's fine." Or, as anyone else would say, "it's bricked."

Re:"Battery" (1)

mikael_j (106439) | about 2 years ago | (#39135155)

The term became "cool" when people figured out ways of bricking iPhones. It was then rapidly expanded to include any kind of malfunction of an iPhone (all in the name of bashing Apple and getting more visitors to whatever blog published the article). These days "bricking" something seems to just be another way of saying "cause any kind of malfunction or failure which temporarily or permanently leaves the device unusable".

(And for the usual Apple haters: Nowhere in the above paragraph did I say iPhones or Apple are perfect or that iPhones can't be rendered unusable)

Re:"Battery" (1)

Anonymous Coward | about 2 years ago | (#39135193)

I really wish people would stop claiming stuff was invented by the iPhone because they never heard of it before the iPhone.

Re:"Battery" (2)

mrclisdue (1321513) | about 2 years ago | (#39135215)

I never heard of rounded corners until the iPad.

cheers,

Re:"Battery" (1)

BasilBrush (643681) | about 2 years ago | (#39135539)

Amazing how the Apple haters manage to bring up the iPhone in every topic. Must be some OCD thing.

We were using the terms "bricked" and "brick" at Symbian back in 1999. And I'm sure it wasn't a new term them. That was a long time before Apple.

Re:"Battery" (3, Informative)

Attila Dimedici (1036002) | about 2 years ago | (#39135557)

Actually, "bricked" did not start with cellphones. It is a term referring to any electronic device that has stopped working. My first experience with it comes from early PCs, where people would talk about turning their PC into a "brick" or into a "doorstop".

Re:"Battery" (0)

Anonymous Coward | about 2 years ago | (#39135607)

it's pre-phone modding, retard.

Re:"Battery" (0)

Anonymous Coward | about 2 years ago | (#39135053)

not sure if trolling, but "bricked" pre-dates iphone by at least a decade.

Re:"Battery" (2)

Sique (173459) | about 2 years ago | (#39135083)

"Bricked" is a term we used long before the iPhone for equipment finally failing to respond to any attempt to get it running again without any evidence of a physical damage.
I've seen many a bricked switch or router in my life which failed during an update attempt :)

Re:"Battery" (2)

the-stringbean (884738) | about 2 years ago | (#39135093)

Bricking didn't originate with iPhone jailbreaking and has been around for considerably longer. I can remember encountering the term for the first time while tinkering with a Linksys WRT-54g back in 2003 and it was already old by then.

Just because the iPhone can be bricked doesn't mean Apple invented the brick!

Re:"Battery" (1)

Anonymous Coward | about 2 years ago | (#39135435)

they just invented the brick with rounded corners

Re:"Battery" (1)

Extremus (1043274) | about 2 years ago | (#39135055)

Defined as someone who wishes they could be a journalist, but doesn't want to actually have to conform to any kind of standards

Sir, could you please point me the direction to those journalism standards you talk about?

Seriously, very few journalists follow standards; not the good ones at least (e.g., priority to reporting facts over writing a nice story, etc). For instance, eventually I come across articles in the newspapers reporting some stories which I have witnessed myself. Every single one of them until today have had factual errors, and some of them quite gross.

Re:"Battery" (1)

The Infamous Grimace (525297) | about 2 years ago | (#39135355)

Did you even try a search? [google.com]

Re:"Battery" (2)

Skater (41976) | about 2 years ago | (#39135631)

For instance, eventually I come across articles in the newspapers reporting some stories which I have witnessed myself. Every single one of them until today have had factual errors, and some of them quite gross.

I've been in the know on a couple situations (both personally and professionally) that were reported in the press, so I wanted to echo what you said. The media gets it wrong. A lot. It makes you wonder how many articles are factually incorrect for topics you aren't intimately familiar with.

Re:"Battery" (2, Informative)

stoolpigeon (454276) | about 2 years ago | (#39135063)

The original post said bricked because that is exactly what the author meant. If you read it you will see this. He says if a car is left sitting long enough it will fully discharge and the car will be inoperable until the owner buys a new $40,000 battery pack from Tesla.

Re:"Battery" (4, Interesting)

gl4ss (559668) | about 2 years ago | (#39135067)

the IDC analyst isn't "just a blogger", it's a guy who's trying to write a rebuttal to sound cool, but too bad he didn't actually go and try to look for the actual cases - instead he's just going "can't happen because of pr materials a, b and c". if he starts with that a battery of batteries can't have anything wrong with it by design.. comes off almost as a fanboi who didn't even read the news piece about the blog posting(which states that you can't even tow them, which sounds a bit strange but not _that_ strange if it won't fire up any elecs. of course you could tow them still lifting it on a truck or whatever)

Re:"Battery" (0)

Anonymous Coward | about 2 years ago | (#39135357)

Semantics Nazi says you can't tow a vehicle by lifting it onto a truck. You can *carry* a vehicle on a truck, but unless it's behind you connected by a rope or similar you're not towing it.

Re:"Battery" (2, Informative)

Anonymous Coward | about 2 years ago | (#39135453)

http://www.wired.com/autopia/2012/02/bricked-tesla-roadsters/

Wired contacted one of the owners, it can't have been too hard.

Summary is right, BMS is probably the cause (3, Interesting)

Jack Malmostoso (899729) | about 2 years ago | (#39135019)

When I read the blog article I thought exactly the same thing. Cells left to self-discharge will not go below their thermodynamic equilibrium, which is more or less the potential at which they are built (remember, Li-ion batteries when assembled are discharged by nature). There is no danger of damaging the cells when self-discharge occurs.
Another issue is when the cells are actively overdischarged, however a Li-ion battery is more likely to explode due to overcharge (plating of Li metal at the negative electrode) than overcharge (insertion of too much lithium in the cathode and electrolyte depletion).

Most likely the BMS is refusing to come back to life unless hooked up to a secret Tesla computer, but I guess the packs can be refurbished.

Also, kudos to the idiot recharging the car with a 30m cable extension (that's what 100 feet is, right?).

Re:Summary is right, BMS is probably the cause (-1, Flamebait)

asim902 (2580935) | about 2 years ago | (#39135089)

www.shoqah.com

Re:Summary is right, BMS is probably the cause (0)

Anonymous Coward | about 2 years ago | (#39135415)

Cells left to self-discharge will not go below their thermodynamic equilibrium, which is more or less the potential at which they are built (remember, Li-ion batteries when assembled are discharged by nature).

BUT, individual cells have slightly different internal resistance so that when placed in series and used, some get discharged further than others. Then one of several cells in series can be destroyed after being left to sit unused, when even a small trickle current feeds from the other cells through the furthest discharged one.

To state the obvious: The "battery" is made up of X cells in series to get a usable voltage, and then many of those sub-batteries are in parallel to create useful capacity at that voltage. If the "battery" has 8000 cells total then X is probably 80 and there are 100 sub-batteries (around 200V).

My theory about what's happening to these cars is that the regenerative braking is mucking up the charge balance between the sub-batteries and some safety circuitry panics when they're too far out of balance.

Re:Summary is right, BMS is probably the cause (0)

Anonymous Coward | about 2 years ago | (#39135553)

Oops. I guessed incorrectly about the battery's design. Further reading revealed the specs from the manufacturer.

Sixty-nine cells are wired in parallel to create bricks. Ninety-nine bricks are connected in series to create sheets, and 11 sheets are inserted into the pack casing. In total, this creates a pack made up of 6,831 cells.

The design sounds like it was chosen to avoid needing balancing circuitry (unless the marketing/PR people are mistranslating what an engineer said). In addition, they've got a liquid cooling system to keep the cells at the same temperature, which further eliminates the need for balancing.

I still stand by my original theory that the battery cells are getting unbalanced from the power spikes made by regenerative braking - just that there's no circuitry involved in balancing the cells being at fault.

I am an electronics technician (whoop-de-doo, right?)... In the past I've demonstrated on some occasions a supernatural ability when it comes to finding the source of problems. But, since it's clear I was wrong about some of the details to begin with, it wouldn't really surprise me if there was a different, obfuscated reason for the battery issues.

Cold Climate? (0)

Anonymous Coward | about 2 years ago | (#39135029)

If you have to park on the street and live in a cold climate, having 8,000 individual cells won't help much. If one cell freezes, all the cells will freeze. If we have a cold snap, I can pull my Subaru’s battery and bring it inside - since it only weighs about 30 lbs. I rather doubt that I can easily pull a Tesla's battery.

Re:Cold Climate? (2)

Jack Malmostoso (899729) | about 2 years ago | (#39135041)

Electrolyte of Li-ion battery completely freezes somewhere around -30C. Degradation of performance (i.e. increase in resistance of the electrolyte and subsequent decrease of available power) starts sooner, but there are additives for that.
I guess there are few places on earth where a roadster is left parked for an extensive period of time in order for the whole pack to freeze.

Re:Cold Climate? (1)

Gaygirlie (1657131) | about 2 years ago | (#39135135)

Electrolyte of Li-ion battery completely freezes somewhere around -30C.

That makes them extremely unwieldy here in Finland as -30C is quite common.

Re:Cold Climate? (1)

amorsen (7485) | about 2 years ago | (#39135243)

Some cars already come with battery heating systems which prevent the problem, unless you park for an extended length of time in -30C without connecting power.

It seems that people living in areas where -30C is common are rather good at dealing with the challenges of gasoline/diesel engines at those temperatures. I am sure that they will find creative solutions for getting electric vehicles running too.

And if no solution is found in the next 10 years, that is probably ok too. If we switch everyone else to electric vehicles, we can probably allow Canada and Finland to continue burning a bit of fuel.

Re:Cold Climate? (1)

EasyTarget (43516) | about 2 years ago | (#39135475)

It seems that people living in areas where -30C is common are rather good at dealing with the challenges of gasoline/diesel engines at those temperatures.

Some places, especially in the northern soviet states, have had what look like 'charging points' along the street for decades. Your car has a simple heater circuit in the cooling fluid (and sometimes ones on the fuel system and in the cabin too) to stop any terminal freezing of the coolant etc.. and give it a better chance of starting. Everybody plugs in on a winter night.

Since when... (1)

martin-boundary (547041) | about 2 years ago | (#39135073)

... do we need to reboot cars now?

Caught red-handed! (5, Funny)

bgarcia (33222) | about 2 years ago | (#39135079)

From Tesla's own description of their battery pack [teslamotors.com] :

Sixty-nine cells are wired in parallel to create bricks.

AHA!!!! SEE? They admit it!!!

Re:Caught red-handed! (1)

Teancum (67324) | about 2 years ago | (#39135257)

Admit what? That they have a real battery pack in their vehicles? I had no idea that anybody doubted that the Roadster was an electric vehicle.

Re:Caught red-handed! (0)

Anonymous Coward | about 2 years ago | (#39135293)

The operative word in Tesla's description is "bricks."

Re:Caught red-handed! (2)

bgarcia (33222) | about 2 years ago | (#39135343)

Admit what? That they have a real battery pack in their vehicles?

Admit that you wouldn't get the joke even if it was a BRICK HITTING YOU IN THE FACE.

Re:Caught red-handed! (0)

Anonymous Coward | about 2 years ago | (#39135361)

WOOSH!!!!
 
It's unreal to me how dense some of you Slashtards are.

Re:Caught red-handed! (0)

Anonymous Coward | about 2 years ago | (#39135385)

Whooosh! Humor is something that happens to other people?

Gravity reversed itself (-1)

Anonymous Coward | about 2 years ago | (#39135101)

Yes, I have a friend of a friend that knows a physicists that said that he reversed gravity on the earth and sent us all to another galaxy. However, he then reversed it and brought us all back again, and we all forgot about it. Oh, and the physicists also claims that he bricked his tesla.

Re:Gravity reversed itself (1)

Anonymous Coward | about 2 years ago | (#39135121)

I don't recall Doctor Who ever having a Tesla.

Re:Gravity reversed itself (1)

Swampash (1131503) | about 2 years ago | (#39135167)

He SAID we all forgot about it. Sheesh.

Re:Gravity reversed itself (1)

tao (10867) | about 2 years ago | (#39135183)

Of course not. You forgot about it when he reversed the gravity again. Duh!

Which Battery? (4, Informative)

labnet (457441) | about 2 years ago | (#39135165)

When you hear Lithium Ion Battery, you need to understand there are many different types of cell.
A battery consists of an Anode, Cathode and Electrolyte.
In LiIon based batteries, the electrolyte is a Lithium Salt, and the Anode is generally Carbon.
In LiPolymer batteries the electrolyte is held in a polymer of Lithium Cobalt or Lithium Maganese (this is the most common format of battery in consumer electronics)
In a recent project a for a hand held RF device, we chose LiFePO4. Mainly because it is so robust. Although it does not have the same capacity as LiPoly, you can grossly overcharge it and even drive a nail through it and it wont catch on fire. It also has much longer life over LiPoly.

LiPoly are very sensitive to overcharge, overdischarge, and mechanical damage, thus have a circuit to disconnect the battery when over discharged, thus the 'bricking' effect.

Tesla orginally used 18650 LiIon batteries with I believe had a LiCoO2 cathode, although I now think they are changing to pupose built cells. They would have a more sophisticated battery management that would prevent 'bricking'...... well at least one would hope...

Depends on cell configuration and BMS (2)

smishra (540867) | about 2 years ago | (#39135175)

The extent of work required upon the failure of a single cell depends on configuration of the cells and the Battery Management System. (BMS).

If Tesla is using 8000 cells, it is probably putting something like 6-12 cells in parallel packs, and then wiring up each of these packs of cells in series. The parallel cell packs provide the current capacity while the packs in series provide the high voltage required to operate the motors.

If an individual cell in a pack goes bad by having a degraded capacity, the capacity of the pack is degraded. However the pack can keep on operating.

If an individual cell in the pack goes bad by having a dead short a potentially catastrophic failure could occur as current from other cells in the pack flows through the shorted cell. There are probably fuses in the pack to prevent this.

The reaction of the BMS to such events will determine whether the car is dead in water or keeps on operating.

There are, of course, many more failure modes - the wiring harness of the cells could be bad, a bolt could come loose, the BMS electronics could fail and any of them could possibly cause the pack to go dead, till repairs are carried out. The engineers who designed this probably err on the side of safety, shutting everything down to prevent catastrophic failure..

The term "brick" is overused these days (2)

PolygamousRanchKid (1290638) | about 2 years ago | (#39135199)

Folks who don't understand what the term originally meant, now use it to describe any tech problem as bricked. As in:

"My browser says 'page not found' . . . my system must be bricked! I read that 'bricked' means 'not working' in the IT business . . . right?"

Re:The term "brick" is overused these days (1)

Attila Dimedici (1036002) | about 2 years ago | (#39135637)

Yes, the term is overused. However, the usage in the original blog post was borderline to acceptable (even if it was wrong). The original blog post said that the Tesla Roadster became unusable if the battery pack became discharged beyond a certain point unless a fairly expensive part (the battery pack) was replaced. Since the claim was that the car could not even be rolled somewhere in this condition the use ofthe term "bricked" was appropriate. Of course, this story is about arguing that the original blog post was wrong.
I just skimmed both articles. The new one does not actually address the point made in the first one, only the oversimplifications that the first one made. The first one contended that if you leave a Roadster sit for 11 weeks not connected to a charger the battery pack will become so discharged that you will need to replace it. The second article says at one point that if you leave a rechargable battery sit long enough without it receiving at least a trickle charge, it will discharge to the point of being forever unrechargable. That to me sounds like the same thing. Now other posters on this site have made arguments that suggest that this is not true for the type of battery used in the Roadster, but that is not an argument made by the article claiming to debunk the first. As I said, the article claiming to debunk the first actually supports the claim made by the first, but then says that there is nothing that can be done about that because that is just the nature of the physics of batteries.

You know... (1)

XrayJunkie (2437814) | about 2 years ago | (#39135271)

... running out of gas turns a car with a combustion engine into a brick.
Same with damage engine, flat tires, ...

Re:You know... (0)

furytrader (1512517) | about 2 years ago | (#39135323)

Ummmm ... does it cost $40,000 to fill your car up with gas? To reinflate tires? It sounds like people who purchased these automobiles were not told that if they failed to keep their cars charged pretty much continuously, they were facing a $40,000 bill. Nothing Tesla has said in response has refuted that. Probably the most intelligent thing I've read about this controversy is that most peoples' understanding of automobiles is developed ad-hoc and that it's dangerous to apply conventional wisdom about gasoline engines to electric vehicles. Nevertheless, people need to know the potential expense they face if, for some reason, they leave their Tesla uncharged or connected to a sub-standard charging source for a long-time.

Re:You know... (0)

Anonymous Coward | about 2 years ago | (#39135493)

You, sir, don't understand the term "brick" and really shouldn't be using it in conversations until you do. Unless you don't mind coming off like a totally ignorant asshat.

To brick or not to brick? (1)

peppepz (1311345) | about 2 years ago | (#39135303)

I find the rebuttal kind of evasive.

The question is: will my battery became unusable (i.e. no longer rechargeable) if I leave my tesla car unplugged for too long? I think it's a fair question and it would deserve a clear answer.

Yes they do brick (0)

Anonymous Coward | about 2 years ago | (#39135467)

Tesla admitted it this morning that the cars do brick. But they are saying that the Model S discharges slower than the Roadster so you'll have more time between charges when the car is idled. but there is no doubt if you fully discharge the battery it is done. Tesla said it this morning.

I wonder (1)

synapse7 (1075571) | about 2 years ago | (#39135517)

If it was news when the first 5 horseless carriages ran out of fuel.

You might want to do your research. (2)

Karth (14680) | about 2 years ago | (#39135561)

Uh... you can easily burn out a lithium ion battery like the ones tesla uses by going below 1% charge. If their system isn't intelligent enough to completely stop battery use at 3%, and report that as 0, it's entirely possible to kill the whole power plant.

is this a paid summary or what??? (0)

Anonymous Coward | about 2 years ago | (#39135603)

The original blog post said if you leave a tesla car alone for a few months (e..g at an airport) then it dies and costs over ten thousand to fix. That neither insurance nor warantee covers this.

Our nice slashdot summary completely fails to contradict this claim. Since it is hte central claim of the blog article, I have to assume that it's true:

if you don't use your tesla car for weeks or months, it dies and costs over ten thousand to replace.

i don't know what tesla can do. maybe have an AAA-type service and an in-computer gps + power meter + cell phone contact; if a car is about to die and cost 10k to fix, then AAA comes and charges it up for Tesla.

does it brick if you don't charge it for x years? (0)

Anonymous Coward | about 2 years ago | (#39135665)

Found out the hard way with a brand new laptop battery, which I stored on a shelf for 1.5 years.

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