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Why Tesla Cars Aren't Bricked By Failing Batteries
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.'"
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.
Good thing slashdot is here to help us debunk everything I'd never have heard about from random dipshit bloggers.
>all that needs to be done is to tow the vehicle to a charger
Another claim was that the vehicles cannot be towed.
Powered by onion juice.
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.
"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!"
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".
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?).
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.
... do we need to reboot cars now?
AHA!!!! SEE? They admit it!!!
I'm a leaf on the wind. Watch how I soar.
I don't recall Doctor Who ever having a Tesla.
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...
46137
He SAID we all forgot about it. Sheesh.
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..
Of course not. You forgot about it when he reversed the gravity again. Duh!
Yes, yes, to the AC you listen.
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?"
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
... running out of gas turns a car with a combustion engine into a brick. ...
Same with damage engine, flat tires,
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.
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.
If it was news when the first 5 horseless carriages ran out of fuel.
It seems Jaffe only speculated the five bricked cars only needed servicing. Jalopnik did the research and also got an admission from Tesla. http://jalopnik.com/5887265/tesla-motors-devastating-design-problem
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.
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.
Found out the hard way with a brand new laptop battery, which I stored on a shelf for 1.5 years.
That is a lot of AA batteries powering that car! Also did these people try doing a battery pull then booting the car into the boot loader and restoring to default? Were they trying to root it?
People who actually own the cars in practice, or some neckbeard who's Read The Fine Manual and determined that it can't happen in theory?
If you were blocking sigs, you wouldn't have to read this.
Tesla stated that because the individual in question had his car unplugged for a prolonged period of time, the battery unit had become damaged and must be replaced at his cost, totaling 41k dollars. The MANUFACTURER stated that the battery was dead after they looked at it. BTW, with no power, the Tesla will now even allow the wheels to turn, there is no neutral. Pretty brick'ish, if not the conventional meaning.
Just another ignorant American.
... and it doesn't look like he has any axe to grind, other than having paid a godawful amount of money for what's now a massive paperweight:
http://jalopnik.com/5887499/who-is-trying-to-smear-the-tesla-battery-problem-whistleblower
Slashdot is losing it (whatever it is). This article is pure Tesla Co. press release.
See what Jeremy Clarkson says about it.....
On reflection, perhaps Captain Slow or the Hamster should be given the task!
And have it be powered by the electricity in the "ether" that surrounds us?
Why is everyone reacting like this is a new concept with vehicles? I bricked my '76 Plymouth Duster when it threw a piston rod through the sidewall of the engine one time. I nearly bricked a horse while walking him through a rocky-bottomed stream when he slipped. The motive force in any mode of transportation is susceptible to going down and effectively making you put wear on the soles of your shoes -- but the electric car will eventually be more reliable (far fewer moving parts and no need for hay/oats or brushing) and it will be far more ecologically sound (less need for oil derricks and belchy/gassy large animals). -- Ace
1000 xp for the first poster who can determine the point of failure they didn't mention.
The Kruger Dunning explains most post on
I always thought that the definition of "bricked" was (paraphrasing): won't start even with a fully charged battery. Is the blogger's brain bricked mewonders?
The big issue is that, while a battery management system can shut the battery down at low charge, the battery will eventually go to zero volts anyway- unless charged. At $40K to fix, this is completely unworkable. IMO Tesla must redesign their battery to be fail safe- that is, if its gets to zero charge, some simpler scheme must exist than total replacement. What have the other manufacturers implemented?
Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?
Battery chargers don't work that way.
They're not going to interpret low input voltage on the LINE side as a problem on the BATTERY side.
AND you are assuming that he's using a poor quality extension cord in an unsafe manner. You have no basis for that assumption.
There are multiple recharge options. The most likely option when using an extension cord is 15A @120V. That's not, as you claim 'many kilowatts'. It is in fact 1.8 KW.
Just RTFA'd and am coming back to rebut you a second time.
Unfortunately, BasilBrush, you seem to not have read the full text of Michael Degusta's article which documents that five Tesla roadsters have been bricked in the US. Furthermore, if you had read through Degusta's post you would understand why one cannot simply tow a bricked Tesla roadster to a charger.
blog
Tesla motors does not deny the fact their batteries can be bricked. They say they have done much to prevent it from happening yet you can destroy the battery pack in much the same way you can destroy a motor if you attempt to run it with no oil. Because the battery pack is composed of many cells both in parallel and in series it is impossible to just unplug it. The pack will always be using power because the cells are in parallel. And because they are in parallel they will always die out if left alone. It is not a problem though in most cases. You must use the car in the way it was designed to be used. Likewise with a normal automobile you must take into account oil, timing belts, water pumps, etc.. Bricking is possible. Know the problems and know how to work around them.
In other news today, we found out that if you let your internal combustion engine car run out of gas it shuts off and does not start, effectively bricking the vehicle. This is Fox news, signing off.
Another option is bringing out a charger to charge the battery *just a little bit* to get the car to activate. I imagine you could make a 50-pound (or less) lithium-ion battery short-charger which could be brought to any flat-battery Tesla which was so out of power it couldn't put the transmission in "tow" mode and charge it up well enough within a few hours (or less) that it would at least be able to do that (making it towable again, a major complaint of the so-called "bricking").
There are a lot of car enthusiasts who don't like electric cars. The writers at Jalopnik (where the Tesla battery blog was posted) seem to be among them, as are the guys at the BBC program "Top Gear". The criticisms that I hear is based on the lower energy density of a battery compared to a consumed fuel like gasoline and the added weight of a battery negates the benefits of using a battery and batteries perform poorly in cold weather. The people who hold this view will then post links to every report of an incident or someone's blog opinion that backs up that criticism and ignore and downplay reports that don't back up their criticism.
I do not know enough about batteries or what is really possible to improve in battery technology, but, in my opinion, the arguments against electric cars have been short sighted. We're not gonna know what is possible or not possible if someone doesn't try.
Just what we need--more "analysts" fighting bad bloggers' bad information with more bad information.
Let's start with the "more than 8000 individual batteries". These are 18650 cells (a standard form factor, a bit larger than an AA cell), and a Roaster has only 6831 of them. They are not "individually managed". Rather, they are grouped into a 69-parallel module, with 99 modules in series. (69x99==6831)
It is asinine and a distraction that Tesla (and everyone else) constantly obsesses about the 6831 cells. For all practical purposes it is a 99-cell Li battery, but rather than using monolithic cell modules, Tesla (like ACP before them) builds modules from smaller component cells, because they yield better cost ($/Wh) and specific energy (Wh/kg), with more-favorable cooling and safety characteristics.
Other than a built-in per-cell PTC device (which Tesla is likely no longer using), any "management" is done at the module level, and the battery is treated as a 99-cell series pack. The PTC is a passive cell protection device, designed to save a cell from a failed-short condition, but they also cause as many problems as they prevent.
Secondly, the "solution" is not nearly as simple as "shutting the pack down" when it reaches "an extremely low depth of discharge".
The Li cells themselves do not discharge themselves quickly when idle--perhaps 5 or 10 percent per year. However, small parasitic (e.g. maintenance) loads will slowly deplete the cells' energy. Herein lies the "grain of truth" that is probably at the center of this greatly dramatized "journalism".
Li traction batteries typically have on the order of 100 cells (or more for 600V systems), and each cell must be monitored to keep its voltage and temperature within a safe range. Typically the monitors are powered from the cell modules directly, and the competing design constraints are many: Small packaging, low cost, low power, electrical isolation, and so on. It is possible, but not trivial (nor cheap) to make a cell monitor draw zero current when its host module is at low voltage.
The original rant (er, blog) claimed that the parasitics would deplete a battery in 11 weeks, which is bordering on implausible, and if true, it would represent a staggeringly high rate of self discharge. Per Chelsea Sexton (who knows what she's talking about), there has not been "a single 'brick' story that didn't involve some extraordinary circumstances".
Lastly is the notion that the traction pack is necessarily destroyed by a deep discharge event. While it is true that deep discharge (and particularly cell reversal) will cause some permanent damage, the damage is in the form of higher impedance, and this is far from rendering the module useless. The battery can be brought back via trickle charging and a per-module impedance test will reveal if any are too far gone.
I've had this happen myself with several Toshiba laptop batteries that I left in a unplugged laptop for several weeks, and a friend of mine had to pay Apple for a new battery when his Macbook-Air was unplugged for a month (while he moved).
In the case of my Toshiba batteries, I was able to open up the two battery packs and construct one working pack from the remaining good cells. The bad cells were unchargeable. (I did this because Toshiba wanted $150 for a new battery pack and I was poor at the time.)
All of these cases involved lithium battery arrays connected to a battery management system where each cell is individually monitored for temperature and charge state.
The Tesla article may be bogus, but it has a ring of truth for me because of my experiences above.
Isn't battery management supposed to be Tesla's thing?
Because the Tesla Roadster is based on a car that I own (Lotus Elise), I have been following Tesla for a while (and then stopped following as they moved on to the Model S). There were lots of delay getting the Roadster to market because, at least in the version of the story that was making it to the public, they were working out battery management issues. They were brought in on the electric version of the smart car because of their expertise in battery management. That is why Toyota put a bunch of money into the company.
If this is a real problem, it says some pretty bad thing about Tesla's expertise in battery management. As noted, thousands of battery cells shouldn't die all at once, unless the battery management system is really not doing its job.
One more thought: At $40k each, it must be economical to repair a Tesla battery pack. Wonder if anyone is trying that.
http://jalopnik.com/5887499/who-is-trying-to-smear-the-tesla-battery-problem-whistleblower
A proper battery management system will shut down absolutely everything (including itself) when the battery is approaching full discharge. In that state, there's no reason the battery pack shouldn't be able to go for a year or two without reaching the point of failure.
Likewise, a proper system would allow the management system to power back on (reboot) when the car is plugged in, and then begin recharging the battery.
The cheapo protected 14500 (AA sized) LiIons I use here have that feature. The disconnected discharge rate is a few micro-amps. If I run it "flat", I can stick it in a charger days or weeks later and charge it back up. Apparently, the Tesla never actually shuts down standby systems and as a result the battery can be irreparably damaged by sitting for 11 weeks (if starting from a full charge) or much less (if the car was driven before sitting).
Other electric and hybrid vehicles do the right thing and go into total shutdown when the battery gets too low. Then you wake it up by plugging it in.
This isn't a general problem with electric and hybrid vehicles, this is a glaring design flaw in the Tesla.
The best way to brick a Tesla is to drive it into a wall.
Unless you want to use another term, a $40k bill to get it running again is fairly bricked.
The original blog poster has a $40,000 quote, and the Tesla manual clearly states that the battery system will require replacement if depleted and not immediately recharged after entering range mode or running to 0% in reserve. They're worried enough about this that they instruct you to contact them immediately if you cannot charge your car.
Read the comments at ITWorld.
This should surprise just about no one, but, frankly, Tesla should have a low-charge relay pull or a manual lever for battery disconnect. Tesla doesn't appear to be arguing the point that their systems can fail in certain conditions, requiring costly replacement. Heck, they put it in the manual.
Simple answer: plug in your car.
And, yes, I still want one.
Apparently the manual for this thing states 7% of the capacity of the battery can be lost PER DAY simply by sitting there.
After some threshold the discharge rate is reduced to 5% per week.
This is crazy.. 7% per day I hear/assume is used for active temperature management, electronics, dc-dc converters..etc.
Whats left after temperature control shuts down is better but insufficient.
They need to shut down *everything* including the management circuts in each string group of batteries when the charge is reduced below a critical level.
The reasons and excuses from the manufacturer don't matter... Current behavior complete with $40k bill is unacceptable to people and this is all that matters.
They really should see if they can go further, though. If they could boost the pack's cell count by just 13%, its power level would be over 9*is shot*
Sounds just like a gasoline car -- if you forget to "fuel" up and are stuck on the road you get towed. Although it is different in that the you can't jaunt over to a maybe nearby gas station for just a few gallons in your gas can.
I like this battery switch station idea by BetterPlace: http://www.betterplace.com/the-solution-switch-stations
The Tesla Roadster most definitely can be bricked. The term brick was actually used by Tesla's engineers and they have publicly stated that at least 5 cars have been bricked. Due to the design of the battery pack, if it ever becomes fully discharged, it is permanently dead. The manual even states that permanent damage will occur if the battery is fully discharged.
You can debate on how hard it is to brick the battery or whether Tesla should fix it, but when the manufacturer recognizes and admits the problem, it's hard to deny it exists.
I love the Tesla Roadster. Here in Enschede, a not so rich city in the east of the Netherlands, one is riding around and I always marvel at the thing. It looks nice and it's so silent! Finally a sports car that doesn't need to make its presence known by lots of useless noise.
-- Cheers!
1) I believe the author means an "extremely HIGH Depth of Discharge" (DOD) as an extremely low one is not a problem at all; it means the battery is essentially full.
2) Batteries are made up of individual cells. When you buy a AAA "battery" you're actually buying a "cell" as there is only one in the entire unit.
3) I HIGHLY, HIGHLY doubt that each cell is "managed independently" as this would require 8,000 different charger circuits if there are indeed 8,000 cells in this battery. *cough* BS *cough*
4) A charger failure = cell failure. Same thing. No charger, cells goes dead, at which point it becomes a load unless there's an autonomous mechanism that removed it from the circuit.
5) I would imagine bulk charging is being done. i.e. the charger voltage is applied across the stacks of cells (I would suspect there are multiple cells stacked in series to provide for the right terminal voltage, and then strings of these cells are placed in parallel to increase capacity).
6) If you discharge a Li-ion cell to less than 2.7V (or so). There is no coming back (without damage). Period. It's not the same as Lead acid or Nickel Metal-hydride as it is with Li-ion.
7) Even if all parasitic loads are turned off, there's still a small leakage path through the sense wires used to control the charger feedback loop. So no, the vehicle cannot sit indefinitely.
8) This author has no idea what he/she is talking about. This is a problem and Tesla has stepped in it big time.
Standby mode in cars, especially electric cars and hybrids, is the not-exactly-off mode that a parked car is in. There is still power to various computers and sensors, so things like remote controls, charge timers, and informatics can function. The Leaf, Prius, and Volt, among others do this with a 12 volt auxiliary battery. The big traction battery is disconnected in this mode. To start the car, the 12 volt auxiliary is used to power the boot process of the computers and to energize the big contactor that connects the traction battery.
If you leave one of theses cars in standby too long the 12 volt drains down and you have to jump a 12 volt source to the 12 volt bus in order to boot the car. I know, I've done it.
Tesla seems to be powering standby mode directly from the traction battery. Volt does this too if you put it in Service Mode. In both cases, you can deep discharge the traction battery. Volt batteries are well protected from damage in that case. Tesla battery protection does not seem nearly as robust.
Car out of gas, must buy new car (in his best dumb ape/caveman voice)
Idiot ignores charge meter in Tesla until battery so low it shuts off. Slashdot says: "omg! Bricked!"
Idiot ignores fuel gauge in car until tank is empty. Slashdot says... ?
What battery cell technology do most of these cars use? According to Tesla's website, it says it is using 18650 architecture cells type. As far as I know, they are the same li-ion cells that laptop batteries use, like the one I recently bought from notebookbattery.com, for my Dell Latitude E6500 laptop. Hopefully neither they, nor Tesla uses the ones made by Sony, that triggered so many laptop explosions a few years back.
Now could somebody please inform Tesla, who have this silliness in their owner's manual:
General information about charging
5-2 Charging your vehicle
General information about charging Charging your vehicle
Important!
Caution: If the Battery’s charge level falls to 0%, it must be plugged in immediately. Failure to do so can permanently damage the Battery and this damage is not covered by the New Vehicle Limited Warranty. Also, if you allow the Battery to fall to a critically low level it may not be possible to charge the vehicle.
There was a letter in the local newspaper auto column the other year about a reader's pickup truck with mysteriously intermittently dying battery (don't remember the make). Long story short, he had ordered the truck with the snowplow package, but without the optional light package for the snowplow package (since the plow blocks the regular headlights, for those lucky enough to not be familiar with snowplows; if you ever see a pickup truck with a snowplow you'll see what I mean) since he couldn't see that his need would include plowing at night. So, the plow package without the lights package included the wiring harness, including the dashboard switch and the relay, with no indicator light on the dash; so without the actual lights there was no way to tell that when the switch was randomly left on it was energizing the relay all night.......