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What happens if Key Battery dies?

Given that the Model S operates automatically off of the Key Battery, what will a driver do if the Key Battery dies. This happened to me once with a Lexus key fob. The battery died and I could not operate the car until I had replaced the battery. But what if you are out on a camping trip or someplace else remote where a replacement battery is unavailable. Is there a backup battery in the key fob? Is there someway to enter an "unlock" code into the car so you can start it? How do you open a door if the key battery dies?

Tesla may already have published the answers to these questions. If so, I would appreciate any links to pages that discuss this topic.

Thanks for your help

Could be. I guess I like to take risks - as long as my time here is finite.

@MandL, thanks for that information. I loved that feature in my Honda Accord and so would miss it greatly in my Model S if it wasn't there. Of course, with constant temp. control in the Model S, I may not be worried about returning to a 120 degree car interior that I want to pop the windows open on.

akimball: Jerry3 posted: "There is a magic place underneath the front wheel well where you can place the fob-with-a-dead-battery and it will open the car. (Posted again). This is in the Model S owners manual."

olanmills: Besides opening car with smart phone, will it run car also I wonder? How can you start car with dead keyfob? akimball raises this issue also. If your cell is lost / stolen, hope we can reset code.

Brian H: Many vehicles will not let a person lock the car if they accidently left their keys in the ignition.

Does anyone know how many keys we get and how much for an additional one?

My understanding is that once you place the fob in under the wheel well, you will be able to drive it because that turns on the car. On the other hand there may be another place inside the car to touch it, but no one has posted those manual pages--if they even exist. I believe that the Roadster works the same way.

You get at least two. There is no valet key because that function is in the software.

I've never heard a price for an additional one. Toyota charges about $200, so I would expect around the same price.

I asked this question at my test drive. The tech assured me that even if the key fob battery dies, the car can be opened and operated by having the key fob close to the car. The car recognizes the key even with a dead fob battery. The car will not let you lock the keys inside. This is good most of the time, but if you are into outdoor sports, water sports, or want to put an emergency key somewhere on or near the car, you really cant. The car will recognize the key and unlock the car. There is no "plastic key" or other emergency key. In my current vehicle, I lock my keys in my car and use a keypad on the door which I installed to enter the car. I also have a trailer hitch that has a tiny safe inside which can hold a key. I dont see any options here for the model S and hope they an arrange somethin that works. I didnt think this was going to be a big deal, but it just might be a deal breaker if I cant use my car to do the sports that I love.

Wrap it in aluminum foil?

Take the battery out and wrap it in foil.

Blocking the passive RFID response is the issue.

My BMW 550 has the 'comfort access' option, which is their name for the remote lock/unlock and car start with the key in proximity. One of my favorite features (along with the HUD)!

One thing: when washing your car you need to take the key out of your pocket and leave it inside (20-30 feet away) or every time you touch the door handles, etc. the car will lock and unlock.

BMW claims you can't lock the car with the keys inside (or in the trunk, etc.) and it has never happened to me but there are posts on that owner's forum claiming it can be fooled. Over all a great feature and on that made the "tech package" a must-have for me.

At present the dead key fob will unlock the car if placed just behind the passenger side front wheel. RFID works at about one foot. Once inside the then opened car, the dead key fob is placed near the front of the driver's seat cushion, which will start the car. A key in the pocket would most likely be withing RFID range.

As far as doing sports, don't people have lockers for changing into sports clothes? The key fob in the locker would not be detected by the car. For scuba or kayaking, why not double zip lock bags, and squeeze the air out? In our lab we use bags that are air tight, which is a step above water tight.

If you lose the bag underwater, fleeing a giant squid or parrot fish, you're "", blued, and tattooed!

How about an RFID patch? Stores use that for inventory tracking, so just marry that to a smokers patch type application. Then you can open your car and start it with a wave of your hand :D

Put it under your skin in the back of the hand and Demolition Man -era has arrived :-)

It's a bit funny that low budget scifi comedy/action manages to show close future that accurately, and big blockbusters fail miserably. I wonder when those three seashells appear in bathrooms...

I would gladly take an implant if I could use that to wave over scanners to ID myself...chip me!

I have been pushing for this for years at my company.

It's funny because I just thought of this and put it on another thread, but we now have finger scans; that's how I log on to my computer. I don't think we need to get drastic and have implants--ooh, that doesn't sound good!

Push on the front of the fob, the trunk opens. Push on the back, the trunk opens. What will open when the fob is in my Jean's pocket and I bend over?

I gladly take implants if they somehow expand my abilities. Cyberpunk-era is not that far either. I just read about guy with both legs amputated under the knee that run 100m under 11 secs with prosthetic legs (South African Oscar Pistorius goes to Olympics to run 400m and 4x400m in their team. After Olympics gets to paraolympics and does 100m, 200m, 400m and 4x400m).

It doesn't take long before synthetic surpasses biologic. Just get "internet" inside your head with access to anyones experience and skills and "resistance is futile, you will be assimilated".

@Timo - real RAM hardwired in and ready to be is not that far away at all.

I wonder how flash updates will be done ...

(I assume it would have to be non-volatile. Otherwise, fragmentation would render it non-functional in no time!)

How do you change the battery in the keyfob?

The underside of the nose of the fob pops off with a fingernail, exposing the CR2032 3V battery, (Same as on the motherboard of most PCs).

so this is actually happening to me now. dropped friends off at the train station and when i got back inside, the display says, "key not inside. car won't start.". have swapped fob batteries but no luck. tesla engineering on the line but no solution yet. kind of a nightmare scenario. sunday so local service not open. car wont move & im in a tow-zone.

It's listed in e manual

@BrianP - If the car will open but not start, make sure you put the key in the cupholder. That's where the RFID receiver is.

I'm copying this post of mine from another thread. It's my campaign to get rid of the fob (or at least give us the option of going fob-less).

The solution for this is to have the functions of the fob built into the mobile app. Require a 4-digit PIN to access the app (or just use the phone security) and and you have a more convenient and more secure fob replacement. Program in all the fob features that people want, like driver profiles, all windows down, go to and display home page, media start, etc.

Surely someone can figure out how to handle the proximity features of the fob via software (GPS?). If TM can unlock your car remotely then they (and us) should be able to do everything else remotely. I have an app that controls my cable box, why can't I have an app that controls my S? It's all talking to a computer through a network.

Keep the fobs home for emergencies (but if you're over 25 how often do you lose your phone?)

@Getting Amped Soon: No need to use GPS to prove proximity to the car. Just use Bluetooth, it already uses cryptographic strong communication. There are garage openers that use the same trick to know when to open.

The manuals,

Extra fob is $249

@Getting Amped Soon
Great ideas. Would love to see them implemented!

You can now access to your car (among other things) with your phone app:

Lock / Unlock / Honk Horn / Flash Lights / Vent Roof.

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