Do you know that you must keep your battery charged?

[AnOutsider]

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.

Ah, so still not a good solution for those who need to park the car and CAN'T be plugged in (like in a storage bay or something).

 

[TEG]

I know of someone who ruined the engine in an old VW. They brought it to their mechanic who said "There is no oil in this engine! When did you last change it?"
The response "I didn't think I needed to - it is air cooled..."

So, yeah, cars need to be maintained and cared for according to the instructions. Some people don't read the instructions and make costly mistakes.

 

[mpt]

Ah, so still not a good solution for those who need to park the car and CAN'T be plugged in (like in a storage bay or something).

Yes indeed, and a valid concern but "I own an EV but it wasn't made clear to me that I must keep it from being discharged" is currently at zero. If that number jumps then we have a messaging issue, if not, then this is all moot.

 

[ElSupreme]

Ah, so still not a good solution for those who need to park the car and CAN'T be plugged in (like in a storage bay or something).

I think your best bet here is to charge the battery to about 80%, unplug the pack from the inverter, and hope for the best. I imagine there is some sort of plug here so in event of a crash you can disconnect the car. You probably only have a year or so doing this. It would be like taking out a cell phone battery. Conditions would play a big factor as heat kills charge. I think Li-ions store best at or below 40F (5C).

Lithium-ion battery - Wikipedia, the free encyclopedia

EDIT: When you plug it back in you have to :HOPE: your car boots back up.

 

[WhiteKnight]

lIn 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.

100% agree every prospective Tesla owner needs crystal clear information and "bricking" needs to happen 0.000000% of the time. And if it happens once in 25,000 cars that's too much.

 

[bonnie]

100% agree every prospective Tesla owner needs crystal clear information and "bricking" needs to happen 0.000000% of the time. And if it happens once in 25,000 cars that's too much.

Would you say the same thing to an ICE manufacturer regarding lack of oil in the engine? Do we expect Detroit to have an engine design that can never fail due to lack of oil?

I think this whole thing is waaaaaaay overblown.

 

[WhiteKnight]

Would you say the same thing to an ICE manufacturer regarding lack of oil in the engine? Do we expect Detroit to have an engine design that can never fail due to lack of oil?

I think this whole thing is waaaaaaay overblown.

Some people are idiots and there is no way around it. But I think the car should be as idiot-proof as possible. With an ICE if you don't change the oil then you're an idiot. With an EV, if you don't plug it in then you probably also are an idiot. But I would hope, given this is new technology for the masses, that Tesla would stress repeatedly to owners and prospective owners the danger of bricking and the importance of keeping the car plugged in when not in use.

 

[dpeilow]

Six separate times it says plug in when leaving or storing the car for a period of time.

 

[eledille]

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

It's definitely not a non-issue, but rather an important issue with a relatively simple fix. Also, this problem is not a general EV issue, it's specific to the Tesla Roadster.

My Think has a somewhat similar problem if the battery should ever be drained completely. Without any traction battery voltage, it can't operate the main contactor, so it's unable to connect the traction battery to the charger. This will not damage its NiCd battery, but the 270 kg battery must then be removed from the vehicle to manually connect it to a charger. The car will switch everything off when voltage drops below a certain point well below nominal voltage (it's practically empty) to prevent this from happening. NiCds have a relatively high self-discharge rate, but even so it will sit there for weeks before it finally fails to charge.

I believe this problem can be fixed by shutting everything down when the battery reaches the lowest allowable state of charge. In this state the battery should still last for months or years without intervention, but at a higher rate of capacity loss due to the lack of temperature management. So the battery will still sustain damage, but much less.

To correct some mistakes earlier in the thread:
Lithium ion batteries have practically zero self discharge. They experience a permanent capacity loss that depends on SOC, time and temperature instead.
Some batteries types tolerate being completely drained. Nickel-cadmium and Altairnano lithium ion batteries are examples.
A 100 foot extension cable can be OK. It depends on the type of cable, required power and amperage.

ElSupreme: I don't think there is any active battery management going on in individual cells. Any such circuitry is conrolled by Tesla, so they can shut it down if they need to.

I'd love to read more about the guy with the extension cable. I can't understand how it's possible to have such monumental losses in a 100 foot cable. How much power does the Roadster consume when in storage?

 

[AnOutsider]

Yes indeed, and a valid concern but "I own an EV but it wasn't made clear to me that I must keep it from being discharged" is currently at zero. If that number jumps then we have a messaging issue, if not, then this is all moot.

Yup, as long as it's made VERY clear on purchase (and I don't mean buried in the manual). For ICEs oil changes are common knowledge -- EVs are new and much about them is NOT known.

I think your best bet here is to charge the battery to about 80%, unplug the pack from the inverter, and hope for the best. I imagine there is some sort of plug here so in event of a crash you can disconnect the car. You probably only have a year or so doing this. It would be like taking out a cell phone battery. Conditions would play a big factor as heat kills charge. I think Li-ions store best at or below 40F (5C).

Lithium-ion battery - Wikipedia, the free encyclopedia

EDIT: When you plug it back in you have to :HOPE: your car boots back up.

Yeah, it wouldn't be a case of me, I'm just speaking for a general consumer. The roadster was mostly rich people and enthusiasts -- Tesla is now tapping into some everyday Joes, and those people will be less attentive and less forgiving of major faults (right or not), so Tesla should be aware and doing what they can to manage it.

 

[Larry Chanin]

The Jalopnik article has been updated to add a statement by Tesla.

Of course they spin the statement as an admission of a problem.

"The argument outlined in this story by Michael DeGusta that originally appeared on theunderstatement.com has been confirmed by Tesla with the following statement:"

All automobiles require some level of owner care. For example, combustion vehicles require regular oil changes or the engine will be destroyed. Electric vehicles should be plugged in and charging when not in use for maximum performance. All batteries are subject to damage if the charge is kept at zero for long periods of time. However, Tesla avoids this problem in virtually all instances with numerous counter-measures. Tesla batteries can remain unplugged for weeks (even months), without reaching zero state of charge. Owners of Roadster 2.0 and all subsequent Tesla products can request that their vehicle alert Tesla if SOC falls to a low level. All Tesla vehicles emit various visual and audible warnings if the battery pack falls below 5 percent SOC. Tesla provides extensive maintenance recommendations as part of the customer experience.

Larry

 

[mpt]

I'd love to read more about the guy with the extension cable. I can't understand how it's possible to have such monumental losses in a 100 foot cable. How much power does the Roadster consume when in storage?

I'm guessing that the current was set to the default of 15 amps at 120V or higher on 240V but the car detected that the voltage dropt at start of charge indicated an under spec cable so simply stopt altogether for safety. This wasn't 'too few volts getting to the car.'

 

[dpeilow]

It's definitely not a non-issue, but rather an important issue with a really easy fix. Also, this problem is not a general EV issue, it's specific to the Tesla Roadster.

LEAF manual

 

[dpeilow]

Here's the guy Twitter

 

[WhiteKnight]

Five separate times it says plug in when leaving or storing the car for a period of time.

So it's in the manual, clearly, and anybody buying an electric car should read the manual. And if you don't then you are an idiot - plain and simple.


The only issue I have is why is Tesla selling the Model S on their website saying:

"The Model S battery will not lose a significant amount of charge when parked for long periods of time. For example, Model S owners can park at the airport for extended vacations without plugging in"

When the Roadster manual (I realize they're two different cars and maybe things have changed) say:

Even when you’re not driving the vehicle, the Battery will slowly lose its charge. Therefore, when you’re not using the vehicle, you should leave it plugged in. However, situations may arise in which you must leave the vehicle unplugged for an extended time (for example, at an airport when travelling for a couple of weeks.) If this is the case, it is your responsibility to ensure that the Battery does not become fully depleted . . . If storing for more than 15 days it is strongly recommended that you keep it plugged in.

So why is Tesla out there selling the car to people with the idea they can park at the airport for extended (two-week?) vacations, while the manual says do not leave the car unplugged for more than 15 days?

 

[qwk]

This is a non issue to me. Asking to follow simple instructions is part of life. If you don't do this in a regular car bad things happen too.

 

[user497]

My situation: I am a daily driver that only drives about 20 miles a day on a normal day. When I go on vacation for 1-2 weeks, I am not need to keep my car in a location where it cannot be plugged in. Here are my thoughts:
- My Tesla ambassador (or whatever they are called) has told me that leaving the car unplugged for 2 weeks is fine as long as the charge of the car is fairly high to begin with. Realistically, I don't think I have ever lost more than 10 miles after a 2 week period.
- I have never gotten a satisfactory answer to whether or not I should plug in every night given that I only drive 20 miles. The manual makes it sounds like I should just so I am always "ready to go" but I am able to figure that out on my own. It also mentions optimizing the battery lifetime by managing the charge but many people believe that not charging all the way (or at least the 90% that standard charging goes to) is not the best for the battery long term. My Tesla ambassador has told me that given how little I drive I don't need to plug in every night as well.
- I do have an issue that the battery reads that I only have 160 miles (which started after owning the car 1 year) on a full standard mode. They believe that is a combination of me only charging on 120V and me only ever going 20 miles before I recharge (which is part of the reason I no longer charge every night but that hasn't seemed to help much).

So in general I will say that obviously I know I don't need to discharge the battery completely or leave it unplugged for a while when it is almost out but I think there is a LOT of confusion/misinformation when you talk about charging nightly, best state of charge and stuff like that. I think part of the reason they have people charge it every night may be for warranty purposes and not because it is the best possible way to maximize the battery life. Of course it probably all depends on how many miles you drive a day and how often you drive and store it. But they could better educate customers or come up with a public formula on the best way to charge given the factors I listed above.

 

[eledille]

dpeilow: I was thinking of the "car is completely dead" scenario. No battery management will cause damage over time, that's just the way it is. Also I didn't consider the possibility that someone would run the car down to 0 and then leave it. Then it obviously will not help a lot to shut it down.

mpt: Ah, ok.

 

[ElSupreme]

So why is Tesla out there selling the car to people with the idea they can park at the airport for extended (two-week?) vacations, while the manual says do not leave the car unplugged for more than 15 days?

I would guess it is one (or more) of four things.

1. The Model S Li-ion cells can accept charge at much lower voltages than the roadster (for whatever reason, chemistry or charging sophistication), which leaves more room after you hit 0 range.
2. The Model S cuts minor loads off the battery more aggressively than the roadster.
3. The Model S's battery thermal management is much more efficient and you won't be burning power to maintain low battery temperature.
4. The Model S has more power after 0 range than the Roadster.

EDIT: I guess they could also mean a 2 week ('extended vacation') so you charge to 100% park the car. Come back 14 days later and charge it.

 

[doug]

So why is Tesla out there selling the car to people with the idea they can park at the airport for extended (two-week?) vacations, while the manual says do not leave the car unplugged for more than 15 days?

Probably marketing getting ahead of themselves. With a larger battery capacity, you potentially have a larger margin for when you next have to plug in. Perhaps they're trying to play this up compared to other EVs. I'd say if you can't plug-in where you park for an extended time, try to park where you have some cellular signal so you can at least check in on your car.