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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

My Kia fob has a pull out metal key to open the door (and glove box, so you can take it out when leaving the fob w/ a valet) and a key "dock" inside the center console that allows the push button start to work when the battery is dead.

I realize Tesla has solved the valet problem otherwise, maybe the Model S fob could have an unpowered RFID chip in it that can be read by placing it somewhere specific even when there is no battery power to send the door open signals? Something like a Zipcar card.

When I visited the dealership in Chicago I asked that question. They tried to show me how it worked but they were having several issues with the car that day. Suffice it to say they explained that by placing the key in an area by the right front wheel well the door will open. I didn't ask how it worked but I am assuming it is probably an RFID chip.

That is similar to the Lexus which works just fine with a dead battery. You hold the battery over the push to start button and the car will start.

I meant the key fob not the battery.

I am assuming it is probably an RFID chip

RFID chip security is quite weak. If there is way to use that to gain access to Model S then it wouldn't be too hard to make "master key" that would open all Model S cars. It would need to be a bit more than just that. Maybe it was wireless charge point where key gets enough power to initialize proper encrypted data transfer between it and the car.

Could TM access/unlock and start the car for you remotely? Or, could there be an iPhone app that can operate the car via your iPhone in an emergency?

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.

Remember the hideaway key?
Just buy a new battery for your FOB in a year and duct tape the new battery under or somewhere outside the car so when the FOB goes dead you have a replacement battery ready.
I already used a backup battery once in the 13 years I have owned my car and it's just a push button alarm. It also doesn't leave a key and access to your car outside to be discovered.

i hope battery replacement in the fob is easier than the same procedure in a Mercedes fob. You almost need a degree in engineering to do the job. The one time i have had to do it, looked up the net - that did help, but it won't if you have no internet connection and your fob goes dead, even if you have a spare battery. also, the job needs to be tool less, or again, you will be in trouble. It also won't hurt if the procedure is obvious. Your manual locked in the car won't help you...
At least Merc has a skeleton key in the fob which will unlock the car....

Is this covered in the owner's manual? (hint: when will a copy be posted here!!!!!!)

Hopefully Telsa has an easy but secure way of unlocking our car when the key fob battery runs out. I agree instructions should be in the manual. They probably are.

Does anyone know how many keys do we get? I hope at least two. If not, how much will it cost for a second backup key in case first key gets misplaced or damaged? I generally have 3 keys for each car. A key for myself, my wife and a hidden backup emergency one.

Is it impossible to lock this key in your car by accident?

Base Murphy's Law:
"It's impossible to make things foolproof, because fools are so ingenious."

I think that the phone app should be able to do this, perhaps with a setting within the car that allows you to enable or disable the feature.

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.

Jerry, Have you seen the Model S owners manual? Can you share it??

There are some screen shots in the TMC. One of the pages just happened to show that.

Thanks, I plan to check it out but hope its all posted soon somewhere!

Posted in its entirety I meant to say

Me too. I would love to have the manual before delivery. I'd also like a new car features manual.

Me too on the manual. I always try to download the manual of any computer or computer accessory before I buy it.

Use your smartphone app to open the doors.

I hope we can also roll down all the windows and open te sunroof with the app as well

From one of those screen shots of the manual - "press and hold to activate the express window down function" - talking about operation of the fob.

Do they give you access to the key fob before you get into the Test Drive car before you get into it? If so, would anyone kindly test the approximate range to operate the doors and most especially the express window.

I used to own a Nissan Altima and could lock and unlock the doors from about 150ft away and could operate the express window/sunroof from approx. 100ft even through walls. Ironically, my Mercedes Benz CLS does not perform as well. I need to be within 50ft to lock/unlock the doors and less than 5ft away from the driver-side door pointing the fob to the door handle to operate the express window/sunroof.

Re: unlocking from a distance

Try putting the fob under your head, just ahead of the "wind pipe", touching. I've done experiments while walking away from a car and found that without this technique I couldn't lock the car, but with it (several steps later away from the car) I could. Nothing like using your head. For an antenna boost, anyway.

@EdG - How big is the plate in your head? and is it titanium or some other metal? ;-)

Fortunately, they haven't picked it up at the airport yet. Try it, you may find out yours is just as big as mine.

Most people I recommend this to are worried about radiation effects on their health. For some reason, they don't worry about AM/FM radio, neutrinos, etc. They generally do worry about cell phones but still talk on them. I tell them about the false notion, still being passed on, of high voltage lines and the fear of cancer:

When I was in graduate school, I passed by a photo of a girl smiling while her head was in a air gap through which a magnetic field of a gazillion Tesla passed. (I don't remember how big the field was, but at the time I was amazed people could manufacture a field that large. It was a HUGE number.) My conclusion was, and still is, if she wasn't killed instantly, little tiny cell phones and the like can't do diddly to your head.

You look a little funny doing this with your keys, though, so make it quick.

Just in case someone wants to get 2 bits in, the units were probably quoted in gauss or even milligauss. Whatever.. I remember it as being way too big an electromagnet.

Another way to boost the signal is to put it against your temple. I'm guessing your eyesockets work like tiny directional antennas and it boost signal to direction you are facing.

What they didn't show you was that 2 years later she looked like Elizasnezer Scrooge and sounded like Daffy Duck. Some things take time to confer their blessings.

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