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Do you know that you must keep your battery charged?

Did you know that you must keep your battery charged? (anonymous)

  • I own an EV and know that I must keep it charged

    Votes: 125 51.0%
  • I own an EV but it wasn't made clear to me that I must keep it from being discharged

    Votes: 3 1.2%
  • I don't own an EV but knew that you had to keep the battery from going flat

    Votes: 94 38.4%
  • I don't own an EV and didn't know that you needed to keep them charged

    Votes: 23 9.4%

  • Total voters
    245

mpt

Electrics are back
Oct 15, 2008
1,746
197
Warren, New Jersey, United States
There's an interesting meme going that battery electric cars can be destroyed if their battery is left to go flat. As an enthusiast and owner I'm in no doubt about the need to keep the battery from becoming completely depleted but are you?

Let me know in the poll. Perhaps there's a message to send out to new owners, perhaps not?


(Note: I altered the date on this post to move it to the top after threads were merged)
 

howabout2

Member
Apr 17, 2010
142
0
There's an interesting meme going that battery electric cars can be destroyed if their battery is left to go flat. As an enthusiast and owner I'm in no doubt about the need to keep the battery from becoming completely depleted but are you?

Let me know in the poll. Perhaps there's a message to send out to new owners, perhaps not?

_______________________________________________________________


What is this business about?

A Tesla Roadster that is simply parked without being plugged in will eventually become a “brick”. The parasitic load from the car’s always-on subsystems continually drains the battery and if the battery’s charge is ever totally depleted, it is essentially destroyed. Complete discharge can happen even when the car is plugged in if it isn’t receiving sufficient current to charge, which can be caused by something as simple as using an extension cord. After battery death, the car is completely inoperable. At least in the case of the Tesla Roadster, it’s not even possible to enable tow mode, meaning the wheels will not turn and the vehicle cannot be pushed nor transported to a repair facility by traditional means.

Has this blog entry/article already been discussed in another thread?
 
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stopcrazypp

Well-Known Member
Dec 8, 2007
10,005
4,923
A Tesla Roadster that is simply parked without being plugged in will eventually become a “brick”.

This can happen to any EV (and any battery) that you discharge completely and leave it uncharged. Self-discharge alone will wreck the battery, even without other drain (and in an EV there are typically other systems that can drain your battery).

The only thing special about the Tesla Roadster is it has a lot of subsystems that keep running, which may increase the speed of discharge. The self discharge of lithium batteries is actually very slow (typically only a couple percent per month).

The Roadster manual actually makes it pretty clear the rate of discharge:
Keep in mind that when the vehicle is left unplugged with a full Battery, the initial rate of decline can be significant. When fully charged, the Battery’s charge level can drop as much as 7% a day and 50% within the first week. When the Battery’s charge level falls below 50%, the rate of decline slows down to approximately 5% per week.

The only one that had an unexpected situation was the person with the 100 ft extension cord (that's a corner case where the drain is greater than the gain, something the Tesla firmware should detect and turn off certain subsystems to reduce the drain; esp. battery conditioning that may happen when plugged in).
 
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Lloyd

Well-Known Member
Jan 12, 2011
6,264
2,056
San Luis Obispo, CA
While there are some truths in this blog, there are also some mistruths. 1. Voltage in Japan, 2. Knowledge that you should not plug in with an extension cord. 3. Parking the car with a discharged battery for an extended time, and more.....

The problem with this type of blog is that there is no effective means of refuting the basis of the post. Some contact should be made to assure that this does not become an issue for new buyers. Like an ICE, you can't run the car without oil or coolant, or damage will result. With an electric car, you can't leave the car in a discharged state, or damage will result. New owners should b e aware. It would be great if there were a procedure to attempt to recover "damaged batteries"
 

Tommy

Member
Mar 3, 2010
882
3
The great OC
Assuming the "bricking" did occur, I am surprised that none of the Roadster owners didn't post here or on Tesla's forum about what occurred. Not being able to move the vehicle and being saddled with a $40k repair wouldn't sit well with me.
 

JRP3

Hyperactive Member
Aug 20, 2007
19,768
44,254
Central New York
Operator error is not covered under warranty. No battery takes well to being completely drained. The extension cord incident is the exception, the car should have compensated or tossed up a warning. The large "idle" loads of the Tesla system has always seemed like something of a drawback. I've had the LiFePO4 cells in my car sitting unattended for 6 months with almost no noticeable self discharge. They don't need any active management when just sitting so I can disconnect the pack from the system to avoid parasitic draw. I think Tesla would be better off just having the pack disconnect from all loads after a certain discharge level is reached, instead of allowing the system to "manage" itself to death.
 

dsm363

Roadster + Sig Model S
May 17, 2009
18,278
151
Nevada
While the article is a little one sided, I hope Tesla has a system on the Model S that simply shuts the car down before that critical level. I'd rather have someone have to tow the car to get charged than replace the battery outside of warranty and have more article like that.
 

Doug_G

Lead Moderator
Apr 2, 2010
17,881
3,347
Ottawa, Canada
This is way overblown. If the car doesn't need to cool the pack, it uses a couple of ideal km worth of total pack energy per day. It takes months to run down.
 

ckessel

Active Member
Jan 15, 2011
4,447
276
Not sure what to think, but it sure sounds bad. If Tesla has 5 bricked Roadsters out of around 2000, then you're talking 50 bricked Model S every year (out of 20k). That's certainly enough to at least cause some seriously bad press.
 

SByer

'08 #383
Oct 23, 2007
1,068
4
Cupertino, CA
I agree with stopcrazypp - the extension cord situation is the only half-legitimate one. But even then... 100ft, really? That's pretty stupid. The others? RTFM. I mean, the one guy was a serial idiot, doing the same thing to a Mini!

Shutting off parasitic losses wouldn't solve the problem - the batteries would still self-discharge. I doubt that the battery pack - or at least most of it's contents - aren't re-useable, though they've certainly sustained damage at that point. As for the Model S, with constant connectivity, it could certainly nag you to death if left alone for a few days without being plugged in. It'll certainly let Tesla know. Sheesh, it's almost as if we don't even teach kids basic physics in school anym... oh, wait, we don't.

The author of the article seems to be one of those over-sensationalistic hit seeker bloggers, IMO.

I also object to the mis-use of the term bricked. The car is certainly not bricked. Replace the battery and it's good to go. That's not bricked. Not cheap, but also not bricked. Of course, like the term 'hackers', trying to correct the whiny-ass use of the word is probably impossible.
 
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ckessel

Active Member
Jan 15, 2011
4,447
276
Part of the problem is it's another hurdle to overcome for an EV. Raising specters along the lines of "Not only might you run out of battery on a trip, but if you don't get it plugged in right away that low battery will turn into a giant $40,000 paperweight!"

You can bank on that FUD being raised and all the more dangerous since it has a tiny kernel of truth hidden amongst the fear mongering. It's something Tesla will need to think about, whether technically or from a PR viewpoint or both. I wonder what the Leaf documentation and policy are on drained batteries?
 
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vfx

Well-Known Member
Aug 18, 2006
14,790
40
CA CA
Well written

I've heard some of these stories from Tesla as well plus one more. Don't they use the same NEMA plugs in Japan as the US? For a while I had a long extension cord. Between the loss and the fans running when the sun directly hit the car cover is would gain about 2 to 3 miles an hour.

The "run out of oil (or water)" is a decent analogy.

The Model S (or Tesla) should send a message to your phone.

The guy says he's got an X on order so his concerns are real. Does he read comments?
 

stopcrazypp

Well-Known Member
Dec 8, 2007
10,005
4,923
The guy says he's got an X on order so his concerns are real. Does he read comments?

I don't see comments on his blog. I did a quick browse of his blog. The last few posts are mostly trashing Android and Google. It seems his blog is dedicated to putting a negative spin on everything he posts. That makes me doubt his sincerity and if things he posts are actually facts (even if spun a bit).
 

stopcrazypp

Well-Known Member
Dec 8, 2007
10,005
4,923
Shutting off parasitic losses wouldn't solve the problem - the batteries would still self-discharge.
Actually I think shutting subsystems probably will do a lot to address the issue. The subsystems probably draw a couple times more power than the self-discharge. The actual draw from the subsystems might still be very small, but compared to self-discharge it is significant. A fully charged lithium battery takes years (not just months) to fully discharge from self discharge. The Roadster takes about 3 months (~11 weeks worse case according to manual).

Of course if you do something stupid like fully discharging the battery (or close) before leaving it unplugged for a long period of time, then even self discharge might doom your battery (but the subsystems probably make it a lot worse). That seems to be the case for almost all the examples (again, except for the extension cord guy).

That said, I don't think it is a huge issue and as EVs get into the mainstream it'll become common knowledge (kind of like fluid/filter changes is now common ICE maintenance knowledge).
 
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GSP

Member
Dec 28, 2007
2,566
797
From the linked blog, not the copy on EVWORLD, there are notes about the Leaf warranty. It seems like Nissan has self-discharge (at the vehicle level) much more under control.

If the author really wanted a Model X, why wouldn't he just keep it plugged in? The only threat is to people that don't realize this is a requirement.

GSP

PS. This reminds me of Martin's "two really nice refrigerators" blog...... Tesla did improve the self-discharge rate of the early roadsters after that.

the understatement: Devastating Design Problem


Notes

Other All-Electric Vehicles
While discharge issues are inherent to lithium-ion battery technology, it’s beyond the scope of this article to address the ramifications for electric vehicles in general. Regardless, a company’s battery management system and obviously their marketing and handling of the situation can vary.

The Nissan Leaf is currently the only other widely available all-electric vehicle in the US. A Nissan Leaf sales specialist was emphatic that their vehicle did not have the discharge problem. The Leaf warranty [Full PDF: Page 9] does however state that the owner must plug in the vehicle within 14 days of reaching zero charge, which does appear to differ from Tesla’s manual that says the owner must do it immediately. [Page 5-2, Column 1: PDF]

Personal Note
I’ve paid $5,000 for a Tesla Model X reservation. Either these issues will be resolved by the time it’s ready, Tesla will be gone by then, or I’ll most likely give up my spot and get a refund. No one has paid me to write this article. TheUnderstatement.com has no ads or sponsors.
 
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Robert.Boston

Model S VIN P01536
Oct 7, 2011
7,844
37
Portland, Maine, USA
This is a serious enough issue that Tesla corporate should address it directly, and publicly. It will be incredibly easy for FUD to pick up selected facts in this blog and do real damage to Tesla's brand name. This is (Volt fire)^2 if left unanswered.
 

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