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Don't let a Model X key battery die

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We were on vacation last week. We left one of the Model X keys in the trunk on the driver side as that's a "Safe" area. They key ended up dying anyway (but the car was locked the entire time). This was on a Wednesday.

On Sunday we finally got around to getting the odd spec'd battery. We put it in...nothing. Tried another battery. Nothing. Tried a new battery in the other fob...it worked. So we knew it wasn't a battery issue.

We called the SC and they said bring it in. Turns out if the key fob is dead too long...it can't be saved. They had to replace it. Odd. We will be leaving spare batteries in the glove box going forward.
 
We were on vacation last week. We left one of the Model X keys in the trunk on the driver side as that's a "Safe" area. They key ended up dying anyway (but the car was locked the entire time). This was on a Wednesday.

On Sunday we finally got around to getting the odd spec'd battery. We put it in...nothing. Tried another battery. Nothing. Tried a new battery in the other fob...it worked. So we knew it wasn't a battery issue.

We called the SC and they said bring it in. Turns out if the key fob is dead too long...it can't be saved. They had to replace it. Odd. We will be leaving spare batteries in the glove box going forward.

this sounds crazy, they didn't charge you $400 or so for the new fob did they?
 
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No charge. They said because it uses both RFID and Bluetooth that if it's dead too long then it can't be paired back with the X.

i think that they may have been wrong...?

on my old car (lexus ls460) i bought a credit card key that was supposed to go to a different model (lexus ls600hl), and it used rfid and was able to be picked up by internal and external sensors throughout the car. all my brother did was hook his laptop to the car's OBD II port and spent about 10 minutes programming it, no problem.
 
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From a technical point of view, this makes no sense. What do they do with a new fob? How is that different from a dead one that was 'revived' except purging the current setup? Totally nuts. Sounds to me someone is just missing some doc for resetting the setup for one fob from the car's database.

I would have said escalate to HQ. :D
 
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From a technical point of view, this makes no sense. What do they do with a new fob? How is that different from a dead one that was 'revived' except purging the current setup? Totally nuts. Sounds to me someone is just missing some doc for resetting the setup for one fob from the car's database.

I would have said escalate to HQ. :D
 

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The FOB must not come equipped with non-volatile RAM (PRAM) and loses it's unique ID with total loss of power. That's the only explanation I can think of, which would surprise me if it's the case (poor design decision).
Sounds plasible, But that then leads to the question, how are they programmed originally? You'd expect the Service Centers to have the same equipment. You can't expect every dead fob to merit a replacement once the battery capacitor (keeping charge as you swap a battery) 'expires'. Or maybe you can.

There is nothing in the manual about 'maximum dead time' when changing battery. There is the interesting note about taking all the fobs with you if you need to add another one, and the maximum number of fobs is 8. So, I wonder if they just add a new one to the car, and the 'dead'/lost ones are never deleted. They may be deactivated, but not 'deleted'.

Very interesting.

Moral of this story, know where they are, and watch out when out of warranty! :D
 
So much FUD and so much BS out of nothing. FOB being dead for "too long" has nothing to do with the issue!

Please read the service report:
upload_2017-7-11_10-34-23.png


Anything defective does not work - no matter how long it was dead or powered.

RFID, used in Tesla FOBs, does not require power! Bluetooth devices don't mysteriously die if left without power "for too long". There is nothing else.

Fallacy:
Turns out if the key fob is dead too long...it can't be saved

Tthe correct conclusion: turns out if the key FOB is defective it cannot be saved
 
We were on vacation last week. We left one of the Model X keys in the trunk on the driver side as that's a "Safe" area. They key ended up dying anyway (but the car was locked the entire time).
Sorry to hear about your problem. I was not aware there was a "safe area" in the car to leave a key fob. When I approach my locked S from the rear with the fob on me I can open the trunk. The car detects the fob when I am standing in back of it. I don't see how it can be "safe" to leave a fob in the trunk. I would never do that.

If a Tesla employee told you that leaving a fob anywhere in the car was "safe" then I think they were incorrect.

In 3 1/2 years of S ownership I have made it a practice to replace the fob battery every year (I do not consider the battery type "odd", they are readily available). Also, I get a warning on the driver display screen when the fob battery is getting low.
 
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I think the "odd spec" statement simply refers to the fact that those batteries are not readily available from most places that sell batteries like Walmart, HomeDepot, Lowes, Sears, etc. (at least not here in Canada). Sure, they're easily acquired from online sources like Amazon or battery speciality stores, but they're not as available as the CR-2032.

I too have heard about the "safe" spot but have never really tested it myself. Not sure if it's a myth.
 
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In 3 1/2 years of S ownership I have made it a practice to replace the fob battery every year (I do not consider the battery type "odd", they are readily available). Also, I get a warning on the driver display screen when the fob battery is getting low.

Indeed, even IKEA sells those 2032 batteries nowadays, at its counters. Have become nearly as common as AAA batteries. Used in wristwatches, mobile GPS devices, range finders, etc. Just have a supply at home as you probably do have with AAA batteries, and change whenever the car tells you to do so.
 
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Indeed, even IKEA sells those 2032 batteries nowadays, at its counters. Have become nearly as common as AAA batteries. Used in wristwatches, mobile GPS devices, range finders, etc. Just have a supply at home as you probably do have with AAA batteries, and change whenever the car tells you to do so.
i have an account with batteries + where once you buy a battery you can trade it in each year for a new one...at no cost.