# Tesla discharge



## somanywelps (Jan 25, 2012)

http://jalopnik.com/5887265/tesla-motors-devastating-design-problem From what I understand, this is because they don't have a main contactor/relay/cutoff... How would you make a design oversight like that? A large relay could just trip if the car is sitting still and keep the batteries from draining any further. Hell I think most cellphone/laptop batteries already do this.


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## Ziggythewiz (May 16, 2010)

Your main contactor cuts off power from the battery to the controller (and motor). Many people run a DC-DC and accessories all the time, but some other disconnect should be used for storage.

Yes, laptop batteries typically protect themselves from overdischarge by forcing everything off. People would freak out if their $150 battery bricked from sitting around for too long.


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## MN Driver (Sep 29, 2009)

The warranty doesn't cover it with the Nissan Leaf either:
"Leaving your vehicle for over 14 days where the
lithium-ion battery reaches a zero or near zero state
of charge"

The Leaf also requires a checkup every 12 months for the 96 month 100k mile life of the battery warranty. The fun thing about that is Nissan pays for the 12 month checkup and the 24 month checkup but you pay Nissan for the next 5 checks at whatever a Nissan dealer wants you to pay.

I've known that the Tesla needs to be plugged in all the time for quite some time and every Roadster owner that I've talked to knows that it needs to stay plugged in. The car constantly runs its battery climate control so in the winter it will be running through the pack to keep itself warm so it better be plugged in. Owners should know this, it's how Tesla designed the car, to always be plugged in and to use a fair amount of energy even when it isn't driving.


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## Ziggythewiz (May 16, 2010)

MN Driver said:


> Tesla designed the car, to always be plugged in and to use a fair amount of energy even when it isn't driving.


I'm amazed at how awesome I thought Tesla was when it first come out, and how less and less impressed I am as I learn more.


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## MN Driver (Sep 29, 2009)

I said that the wrong way, since it is using Lithium Cobalt cells, they can't be charged at freezing temperatures without lithium plating the cells, so Tesla heats the pack. They also need heat since their low C rate cells sag so much more when cold. I'm thinking that the Tesla really needs a big pack to compensate for using less capable commodity cells.

...at the same time I'll have a higher voltage pack than I otherwise need in my conversion to add performance, especially in colder weather and when I want to drive spirited.

I think I said the part about high energy use wrong but in reality if you are constantly controlling the temperature of the pack it will constantly use a fair bit if the weather isn't ocean coast California where the temperature is held fairly constant by surrounding water.


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## Ziggythewiz (May 16, 2010)

I understand the need to take care of batteries in use, but I'd think they could come up with a better way than constantly running stuff. Some good insulation and the battery case shouldn't get far off, and maybe a remote start on the climate control or something.

The prius with the solar roof drives me crazy too. Why not tie that panel into the main pack and put the climate control on a timer? My car doesn't need to be constantly cooling all day.


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## somanywelps (Jan 25, 2012)

With so much money on the line (the battery pack), not having a zero charge protection relay or something is inexcusable though.


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## MN Driver (Sep 29, 2009)

...yeah, easy answer would be to save everything that needs to be saved into non-volatile memory and disconnect the pack before it hits say 5% SOC which I think would completely shut down the car. 100% agree. Even if Tesla would have to get it towed in or have one of its mobile dispatch units charge you a boat load to professionally 'jump it' by making sure nothing actually hit zero and giving it a charge after powering the contactor and make sure everything is okay, it would save the customer tons of cash and grief.


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## DJBecker (Nov 3, 2010)

Ziggythewiz said:


> I'm amazed at how awesome I thought Tesla was when it first come out, and how less and less impressed I am as I learn more.


I have the same reaction, but you should view it from a different perspective.

When they started, they were building a low volume specialty car. They had no past and a small market. Investing in engineering is expensive and risky. So they bought off the shelf and outsourced everything they could. The chassis, brakes, wheels, motor, controller, etc. all came from existing sources. There was no source for the battery pack, control electronics, and transmission, so they had to design and build those parts.

Today they are well known as the premier high-end electric car company, with a reputation bigger than their original capabilities. With the federal stimulus money, they have far more money to design a production car. We've yet to see how they do.


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## MN Driver (Sep 29, 2009)

I've seen a few 'good deals', but like most people it is still out of my price range of the Roadster two summers ago but one was a Ferrari/Porsche/etc exotics dealer and it sat on Craigslist and reposted once a month for about 3 months. I'm not sure if the dealer would have simply used the 120v charger and got away with it or if they rigged up the previous owners charger to the shop temporarily. I'm having a hard time with the thought that the life support system for the battery supposedly was a death sentence for a Roadster while it was plugged in. That is the part that bugs me the most about this.


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## jeremyjs (Sep 22, 2010)

It seems really strange to me that with how sophisticated their battery management system is to keep low grade consumer cells happy 24/7 they wouldn't have had a fail safe that isolates the battery from any power draw once it reached some low limit, like 5-8%. It seems like it would have been relatively simple to design something like that to safeguard from turning the car into a brick.

Heck even most laptops made in the the last 5+ years have that kind of safety system built in to keep you from bricking your battery


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## Guest (Feb 23, 2012)

Your all running with a hearsay article and reacting exactly like those who wrote it want. You all take a tiny bit of misinformation and run all day long with all the knowledge and smarts of a typewriter. What drama. What speculation. It's bull shit.

If packs are dead from disuse its because they are stored and never used or charged up. Other than that its total bull shit. Yet not one single issue noted with the Leaf but now 5 Teslas are what is being termed as bricked. Bull shit.


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## jeremyjs (Sep 22, 2010)

http://theunderstatement.com/post/18030062041/its-a-brick-tesla-motors-devastating-design

"The amount of time it takes an unplugged Tesla to die varies. Tesla’s Roadster Owners Manual [Full Zipped PDF] states that the battery should take approximately 11 weeks of inactivity to completely discharge [Page 5-2, Column 3: PDF]"


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## Ziggythewiz (May 16, 2010)

Yes, and they say you shouldn't leave it unplugged for more than 48 hours if it's under 15% charged. At 15% it would take under 2 weeks for it to brick.


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## MN Driver (Sep 29, 2009)

gottdi said:


> Your all running with a hearsay article and reacting exactly like those who wrote it want. You all take a tiny bit of misinformation and run all day long with all the knowledge and smarts of a typewriter. What drama. What speculation. It's bull shit.
> 
> If packs are dead from disuse its because they are stored and never used or charged up. Other than that its total bull shit. Yet not one single issue noted with the Leaf but now 5 Teslas are what is being termed as bricked. Bull shit.


Not quite, this sort of thing has happened in a slightly different way on the Leaf forum but the drivers of the Leaf are more likely to use it as a daily driver rather than the weekend nice day performance ride that most people who buy expensive exotics do. On the Leaf forum there is at least one example where the car hit the Leaf's empty point and it had to be towed and the owner and the dealers were unable to get the car to turn off because it refused to until a Nissan dealer would pull the details and clear it. The Nissan Leaf is probably a little more idiot proof by design than a vehicle originally slated for low production to high income individuals who usually don't like to point themselves out too much.

There have been problems with the Roadster though, there is a guy on Youtube that I used to find in searches who has great things to say and he had to have one of his main modules(if I remember right I think there are 7) swapped out by Nissan after he plugged it in one day and it didn't charge.

You can call it misinformation and speculation but its clear that the issue at hand is that you can't park one of these without it draining itself completely. This is different from a DIY LiFePO4 conversion in that if you disconnect the pack and let it sit for a few months it isn't dead when you come back. You can call that bullshit but I don't agree. Do I think it's a huge deal. For the Roadster, not so much but as an issue that should be fixed with a higher volume S and X, yes I think it isn't something that should be left alone.


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## Guest (Feb 23, 2012)

Can't leave the Leaf alone either. It is CLEARLY STATED IN THE MANUAL AND THAT IS ALSO CLEARLY STATED IN THE TESLA OWNER MANUAL TOO. 

It is all BULL SHIT. Of all the Leafs on the road not one mention of a bricked car. NOT ONE. The issue is total bull shit. 

I own a LEAF and the Tesla article is total BULL SHIT. 

Ignorance of the OWNER MANUAL is not a FREE RIDE. Its total BULL SHIT. 

What, 5 cars reported now in one article? BULL. 

BULL BULL BULL BULL


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## palmer_md (Jul 22, 2011)

http://green.autoblog.com/2012/02/23/tesla-bricked-battery-story-may-have-a-short-circuit/



> Yet, a few minutes spent with Google shows that Drucker and Degusta are also business partners, having registered at least four corporations together in California, according to Corporationwiki. It also turns up this article, from the Nov. 15, 2000, issue of Insurance & Technology magazine, a profile of Drucker, in which he is quoted describing Degusta as his "partner in crime." Indeed, we wonder if the famously litigious Tesla might be considering another libel lawsuit against this muckraking duo.


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## MN Driver (Sep 29, 2009)

I agree with you that not following the manual is not a 'free ride' to get a new battery under the warranty.

The idea is that Tesla should disconnect the pack before it destructs itself. The fact that Tesla doesn't is what is at question. It's a simple and easy thing to do. If it requires a tow to get the pack reconnected wouldn't be a big deal if it required that versus a $40k battery swap otherwise. Usually cars fit safeties to try to at least partially idiot-proof things. My cars don't let you run the engine past red-line for example, saves some engines. I had a car with an automatic that also would cut the fuel supply and wait for engine revs to level off to a safe level before engaging the transmission to avoid warranty claims. It's stuff like this that I think Tesla should implement.

Read the issue a little bit, by saying its bullshit is taking it a little bit on the black and white. The Leaf did one thing right, it doesn't draw from the main pack on standby and uses a 12v battery for the standby loads. I'm not sure how the cold weather kit works but I'd hope that it won't drain the pack too much when the car is sitting, I'll have to read into that a bit but I'd imagine it isn't a big deal.

In the end, would this prevent me from buying a used Model S 5 years down the road? No. Do I think its a super big deal? No. Am I trying to make it seem like its a huge deal? No. Do I think that Tesla should try to do something about it to try to avoid an issue and maintain credibility and prevent issues that might cause PR problems and possibly hurt the adoption of electric cars? Absolutely.


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## Guest (Feb 23, 2012)

I don't think there is an issue at all. I'd love to see all the forum guys call up Tesla and tell them what they need to do. I am also quite sure that TESLA has gone through all this already. I doubt it's as easy as you and others make it out to be. If it were only that simple. 

The story IS bull shit. 

BLACK AND WHITE.


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## palmer_md (Jul 22, 2011)

gottdi said:


> I don't think there is an issue at all. I'd love to see all the forum guys call up Tesla and tell them what they need to do. I am also quite sure that TESLA has gone through all this already. I doubt it's as easy as you and others make it out to be. If it were only that simple.
> 
> The story IS bull shit.
> 
> BLACK AND WHITE.



Proclaiming BS is not an argument. You'll not win any followers with that logic. Do I think there is a big issue? NO. Do I think Tesla is doing something about this? Yes. Is the article unbiased? In my view, NO. 

What is your specific disagreement with the author? Do you think that there were not 5 cars that ended up with a "dead" battery? 

I agree with you that this is much ado about nothing. But I can't follow your leap to the article being complete BS.


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## Guest (Feb 23, 2012)

I claimed BS before the latest article posted above was posted. It is bull because it takes into account everyone else being smarter than all the engineers at TESLA and saying that TESLA did nothing to fix or prevent the problem. 

You can't fix stupid. Stupid people will run the car dead. There is no fixing STUPID. 

I am not out to gain followers. Never have been.


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## Guest (Feb 23, 2012)

I disagree that it was the fault of TESLA.


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## Ziggythewiz (May 16, 2010)

gottdi said:


> You can't fix stupid.


Would you then care to explain Apple's success?


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## Guest (Feb 23, 2012)

Superior Design from the beginning. Every one else followed CHEAP. Been with APPLE since the late 80's. Nothing Stupid about the product. They may have made bad business dealings but the product has never been bad. EVER.


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## Guest (Feb 23, 2012)

Nope, you can't fix stupid.


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## Ziggythewiz (May 16, 2010)

gottdi said:


> Superior Design from the beginning. Every one else followed CHEAP. Been with APPLE since the late 80's. Nothing Stupid about the product. They may have made bad business dealings but the product has never been bad. EVER.


I wasn't referring to the product.


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## Guest (Feb 24, 2012)

But the Tesla Article is about the product. Whats the reference then?


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## EVfun (Mar 14, 2010)

MN Driver said:


> I agree with you that not following the manual is not a 'free ride' to get a new battery under the warranty.
> 
> The idea is that Tesla should disconnect the pack before it destructs itself. The fact that Tesla doesn't is what is at question. It's a simple and easy thing to do.
> [snip]


I don't think any auto manufacturer will be running Lithium Cobalt cells without a cell level BMS.

I can kill all loads in my Buggy by simply pulling one 30 amp fuse. If I had a BMS I could kill all but about 2.8 milliamps of load by pulling that fuse. How would I simply and easily kill that load?


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## Ziggythewiz (May 16, 2010)

gottdi said:


> But the Tesla Article is about the product. Whats the reference then?


The reference is to building something that just works, and even better with stupid.


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## ElectriCar (Jun 15, 2008)

I've done control electronics for years. It's not cost, it's a decision they made and I bet you they fix it in new production models. It's asinine that they would leave a $40K pack vulnerable to self destruction because SOMEBODY is not going to do what the manual says or something is going to come up and someone will forget to plug it up. To say people calling it an issue is BS is BS! It's not BS, it's absolutely stupid to not prevent this. 

If it were my design, I'd have it disconnect the entire pack at a safe point. So it can't charge at low temps? So you design the electrical system such that once plugged in after the low SOC shutdown activates, the pack will have to heat on line power until the pack reaches a safe temp. At that point the car can begin charging the pack. 

So what if people bitch about having to wait on the pack to heat up then charge. The alternative is a $40K battery replacement and without the shutdown you don't just wait a few hours, you wait for days! What is stupid is they made a decision to not do this. I'm sure they have capable electricians on staff who could figure this out. It doesn't take an engineer to design this, it's seriously basic control wiring. 

Assuming I could get into the wiring and had access to the wiring diagrams it would be absolutely nothing to modify this from an electrical standpoint. The only difficulty I can see possibly being an issue is finding a place to install the devices.


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## Ziggythewiz (May 16, 2010)

EVfun said:


> I don't think any auto manufacturer will be running Lithium Cobalt cells without a cell level BMS.
> 
> I can kill all loads in my Buggy by simply pulling one 30 amp fuse. If I had a BMS I could kill all but about 2.8 milliamps of load by pulling that fuse. How would I simply and easily kill that load?


It's not a 2.8 milliamp load that's pulling a 53kWh pack to 50% in 1 week and the other 50% in 10 more.


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## MN Driver (Sep 29, 2009)

EVfun said:


> I don't think any auto manufacturer will be running Lithium Cobalt cells without a cell level BMS.
> 
> I can kill all loads in my Buggy by simply pulling one 30 amp fuse. If I had a BMS I could kill all but about 2.8 milliamps of load by pulling that fuse. How would I simply and easily kill that load?


This isn't about a BMS, the pack being loaded by the whole support system of the car. If you are saying that Tesla doesn't have a BMS, you should spend some time on their blog reading about how the Tesla manages their battery. You might need to look way back toward the beginning when they were just releasing the car or a bit before while it was in the planning stages, they don't exactly call their system a BMS but the pack is not sitting without being managed.


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## EVfun (Mar 14, 2010)

I was suggesting that it is easy to remove the external loads from the pack when it gets too low, but it is a lot harder to remove the cell level loads from the battery management system.


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## glaurung (Nov 11, 2009)

So if your garage blows a fuse and you do not notice this, it may cost you a battery pack?


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## Ziggythewiz (May 16, 2010)

Don't leave your house. Ever.


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## gor (Nov 25, 2009)

tesla says - it's all rumors - shouldn't be any "brick" problem... battery protection systems won't let it happen...

.... http://www.teslamotors.com/blog/plug-it

"Even in cases of neglect, the latest Tesla batteries are industry leaders. The earliest Roadsters will take over two months to discharge if parked at a 50 percent charge without being plugged in. From that starting point, Tesla has consistently innovated and improved our battery technology. For example, a Model S battery parked with 50 percent charge would approach full discharge only after about 12 months. Model S batteries also have the ability to protect themselves as they approach very low charge levels by going into a “deep sleep” mode that lowers the loss even further. A Model S will not allow its battery to fall below about 5 percent charge. At that point the car can still sit for many months. Of course you can drive a Model S to 0 percent charge, but even in that circumstance, if you plug it in within 30 days, the battery will recover normally."
-------
- hmmm... just a rumors? ... why they don't call guy a liar? it was clear accusation, not just a rumor ... and there is court responsibility for spreading false information, damage to a good name and reputation...
- what actions been and should be taken in such case? what is going on?


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## somanywelps (Jan 25, 2012)

I note they didn't say the battery won't die...


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