Do you know that you must keep your battery charged?

[AnOutsider]

ElSupreme, again, it's easier to do in a vehicle than an appliance. I, for one, love to drive to the airport, park, and leave my car there so that when I return I can jump in and head home without waiting for someone or having someone wait for me. Tesla even mentions on their site that you can do this.

Now, if I live say 20 miles from the airport, am running late, get there with 30 miles range left and park it (thinking, rightfully, that I have enough to get back home when I return), how long can it sit there before I don't have enough to get home? How long can it sit until the battery hits zero? How long after that until the battery is damaged?

I'm willing to tiptoe around the issue and make sure it doesn't happen, but I need some facts from Tesla. Am I screwed as soon as I hit 0? If not, how long after? How much does the battery drain when not plugged in and how fast? Why aren't there counter-measures to stop the drain once you hit a certain level? I saw in the investing thread that Tesla responded and said your car can alert you when it gets to 5% -- well, if I'm thousands of miles away and it's sitting in an airport lot -- not a lot of good that'll do unless someone can go out and get it (friend, family, ranger?). Why doesn't it just shut itself off?

Again, just give us some facts and stop sugar-coating it.

 

[AnOutsider]

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.

There's no poll haha. But, no, I did not know that you could permanently kill your battery if the charge hit 0. I also was under the impression Tesla prevented this from happening by making sure to keep some juice in the pack. I was apparently wrong.

 

[PV4EV]

A lot of devices with commodity lithium's can also 'brick' by the same analysis, laptops, digital cameras, even phones. If you leave them unused long enough then the small amount of self-discharging and any small parasitic losses will eventually cause the lower critical voltage to be passed making the cells more or less useless.

I've also had plenty of ICE cars that have ended up with flat / dead batteries in cold weather through lack of use, even after 2 or 3 weeks. Cars with leaky engines which eventually loose all their oil will suffer internal damage or cease up, if the owner doesn’t do something about it. Cars with tyres that slowly loose pressure will eventually ruin the wheel rim or cause you to crash, unless the owner does something about it. Etc etc.

Basically, anyone buying a car surely has to understand than they must care for their vehicle to some degree. I think anyone who wants EV and then expects to park it outside for 3 months without once using it, and without plugging it in … is asking for trouble. And its not that much different for ICE cars.

 

[mpt]

ok,ok, speedy, the poll gets added after the topic

 

[3lectronica]

Jalopnik - Tesla Motors Devastating Design Problem

Have any Roadster owners on TMC ever had to replace a battery because of negligence?

Tesla Motors Devastating Design Problem

 

[mpt]

...I also was under the impression Tesla prevented this from happening by making sure to keep some juice in the pack. I was apparently wrong.

This is a question that needs an answer. When I go on vacation I leave the Tesla in 'Storage' mode. I think that, judging by how much my MINI E didn't discharge after three weeks, you'd need to leave the car for years to suffer a problem. Perhaps the phantom load on the Roadster is high. I'd expect it to shut down completely at a low state of charge.

 

[ElSupreme]

I killed a cell phone Li-ion this way. Was out of juice and HAD to contact someone. Turned it on sent text. Phone dies. I turn on phone about 20 times in 15minutes until I get return text. Phone would not accept charge after this.

It is a problem with being able to safely recharge the Li-ion cells. Their safety circuits prevent thermal runaway and also 'flat' recharging. You can remove the safety circuit and attempt to charge them but run risks (I think thermal ones). I think someone needs to start a battery recovery center! Could be lucrative.

Lithium-ion battery - Wikipedia, the free encyclopedia

 

[bonnie]

Ouch. The number of tweets about 'bricking' is growing.

 

[NigelM]

I can feel a "warning sticker" coming on......

 

[mpt]

I can feel a "warning sticker" coming on......

Which is all this hoo-har probably amounts to.

 

[WhiteKnight]

There's no poll haha. But, no, I did not know that you could permanently kill your battery if the charge hit 0. I also was under the impression Tesla prevented this from happening by making sure to keep some juice in the pack. I was apparently wrong.

When "the car hits zero, the battery is not at zero. So, at 5% or 10% state of charge the car shuts down. With that 10% of battery (0 miles of range) remaining you then have 1-2 weeks to plug it back in. I just read somewhere (can't remember) it would take 11 weeks from full or 1-2 weeks from empty to "brick" your Tesla.

It is very unlikely that you are going to show up at the airport and park for a 2 week trip anyway (a limo both ways has got to be cheaper than parking that long). But if you did you would want to make sure your battery pack was not drained down to 0 miles range and/or you could plug it in at the airport (like LAX). Showing up at the airport with zero miles range defeats the purpose of parking at the airport in the first place.

 

[dpeilow]

Naturally, but it doesn't seem like this is a non-issue?

Absolutely. We've known on here for as long as I can remember that you need to keep the car plugged in in storage mode if it's parked up.

However it's pretty suspicious that just as they get a lot of good PR around X sales, all the usual FUD sources dig up this one.

 

[ckessel]

However it's pretty suspicious that just as they get a lot of good PR around X sales, all the usual FUD sources dig up this one.

Probably just an awareness. Somebody looking into EVs that hadn't much before or basically an older story that never got traction before gets it now due to higher awareness. It's FUD, but I'm not sure I'd chalk it up to conspiracy generated rather than random opportunism for whoever stumbled across the "story".

 

[AnOutsider]

ok,ok, speedy, the poll gets added after the topic

lol.. hey now, my post was 3 minutes after yours!

This is a question that needs an answer. When I go on vacation I leave the Tesla in 'Storage' mode. I think that, judging by how much my MINI E didn't discharge after three weeks, you'd need to leave the car for years to suffer a problem. Perhaps the phantom load on the Roadster is high. I'd expect it to shut down completely at a low state of charge.

I assume storage mode depletes slower. I guess the Model S will have this mode as well. Does it stop it from completely depleting?

It is very unlikely that you are going to show up at the airport and park for a 2 week trip anyway (a limo both ways has got to be cheaper than parking that long). But if you did you would want to make sure your battery pack was not drained down to 0 miles range and/or you could plug it in at the airport (like LAX). Showing up at the airport with zero miles range defeats the purpose of parking at the airport in the first place.

Note: I didn't say 0 miles range, I said 30 (or enough to get home). I wanted to know just how quickly that X miles would deplete.

In the end, I'm sure this will be a rare occurrence, but I do think there needs to be clear information from Tesla on the situation.

 

[mpt]

Storage mode maintains the battery at around 20% charge. Basically it allows it to drain down to 20% then holds it there. I've plugged my car in at 40%, left it for three weeks and come home to find it at, guess.. about 40%.

As an aside, A friend of mine and PA roadster owner left his car in CA for months simply plugged into a 120v outlet - no probs at all.

 

[AnOutsider]

Storage mode maintains the battery at around 20% charge. Basically it allows it to drain down to 20% then holds it there. I've plugged my car in at 40%, left it for three weeks and come home to find it at, guess.. about 40%.

As an aside, A friend of mine and PA roadster owner left his car in CA for months simply plugged into a 120v outlet - no probs at all.

OK, so it goes down to about 40, then stops doing whatever it usually does that drains the battery? Does it have to be plugged in as well or doesn't matter? I imagine if it's plugged in it still maintains the pack but only draws enough juice to keep it level at about 40%? If this is the solution, then I would guess the instances quoted in the articles (except for maybe the extension cord) were just owners not placing the car in storage mode (i.e. negligence)?

 

[donauker]

To most of us techie types it seems rather obvious to keep our EV charged at a safe level.

But how many Roadster owners know how many miles are drained from the pack by active cooling of the battery while the Roadster is parked in the sun for a day during a typical July/August heat wave?

 

[mpt]

Storage mode lets the car do its own thing, slowly allowing the battery to deplete. When it hits about 20%, it begins to charge the battery from the utility feed; so, yes, plugged in. It also manages the temperature so it will start the heating/cooling if needs be.

 

[ElSupreme]

I assume storage mode depletes slower. I guess the Model S will have this mode as well. Does it stop it from completely depleting?

No it won't Li-ion batteries include 'maintenance/safety' circuits on the cells. They are passive circuits that prevent the cell from discharging out of control. This is to prevent theremal runaway (read: explosion). And they continually draw power, it is a VERY very small amount of power. I imagine for numerous reasons Tesla actively monitors cell/battery health, which will consume some power, but probably not enough to kill the battery in less than 2 weeks after you have 0 range.

In general after your batteries go 'flat' and will not charge, you can still recover the battery. It requires removing the safety circuits and attempting to charge the cells directly. It is dangerous as I believe you can start thermal runaway in some cells. I am not sure how sophisticated Tesla's charging software/hardware is but I imagine they are a lot closer to the batteries lower limit than a cell phone. So there is probably only a small window to get this fixed.

You really have to neglect your vehicle for this to happen. Just like driving cross country you can't think of an EV like an ICE. There are billions of dollars of ICE 'charge' infrastructure. And almost no EV infrastructure. Leaving your 'on fumes' car at the airport for half a month seems to be a bad idea.

 

[clea]

I would like to know if the battery warranty would cover it if you end up bricking your car. Somehow i doubt it because not keeping the battery charged to a minimal level would, i assume, void the warranty but it would be nice if this was spelled out so that any owner would probably take notice if they weren't aware of the issue beforehand.