# Keycard Maximum Temperature?



## aadams1278 (Jul 8, 2018)

I’m getting a Model Y and later a Cybertruck for towing. One of the uses will be Jet skiing. I have a stand up Jet ski which has no real usable storage space on it for keys. Towing with my current ICE car, I typically lock my wallet and phone inside the vehicle, and put my keys inside the black plastic storage box on the front of the trailer. This box is locked with a combination lock.

The question is, when I transfer over to towing with a Tesla and start locking the keycard in that black plastic storage box, will the very high temperatures inside damage the card? I have no idea exactly how hot it gets inside there, but it’s a black box in direct sunlight for several hours in the middle of summer (90+ degrees). I would expect temperatures of 120+ are reasonably expected.

Does anyone know the resilience of these keycards to temperature? I would prefer not to carry the keycard with me on the water, and the current system I have seems to work well for me.


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## JasonF (Oct 26, 2018)

aadams1278 said:


> Does anyone know the resilience of these keycards to temperature? I would prefer not to carry the keycard with me on the water, and the current system I have seems to work well for me.


Put the keycard in a small plastic ziplock bag, seal it, and wear it somewhere it won't fall out into the water. The keycards are much more resistant to water than to heat.


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## lance.bailey (Apr 1, 2019)

can you get a small insulated bag for the card? like a bubble mailer? or steal some tinfoil from a friend's hat to reflect heat? would that keep the cool side cool?

if you lock your phone in the vehicle, does that not stop the car from locking? Normally my 3 locks up when I leave it in the garage, but if the phone is on the chargepad, the car does not lock itself and I can easily open the car without my keycard. You may want to test the accessability of the car if you leave the phone in it.


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## aadams1278 (Jul 8, 2018)

lance.bailey said:


> can you get a small insulated bag for the card? like a bubble mailer? or steal some tinfoil from a friend's hat to reflect heat? would that keep the cool side cool?
> 
> if you lock your phone in the vehicle, does that not stop the car from locking? Normally my 3 locks up when I leave it in the garage, but if the phone is on the chargepad, the car does not lock itself and I can easily open the car without my keycard. You may want to test the accessability of the car if you leave the phone in it.


I debated explaining that in my first post. I anticipate turning off Bluetooth while leaving the phone in the car so the phone "key" is disabled. But insulating the keycard is an idea.


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## jmaddr (Apr 10, 2019)

If you don’t mind wearing a ring, look at the key rings they have where the put the RF chip from a Tesla card into a ring. I do my ocean swims with one.


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## lance.bailey (Apr 1, 2019)

yeah, i just tested this.

opened car (iphone in pocket), left phone on charge pad, locked car with key card.
walked away
walked back and opened the car without any issue, without needing the key card. 

darn smart cars.

maybe if you power down the phone completely - I would not trust just turning off bluetooth.


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## lance.bailey (Apr 1, 2019)

jmaddr said:


> If you don't mind wearing a ring, look at the key rings they have where the put the RF chip from a Tesla card into a ring. I do my ocean swims with one.


very cool.

what about smart watches? can you pair to a smart watch? are they water friendly?


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## garsh (Apr 4, 2016)

aadams1278 said:


> Does anyone know the resilience of these keycards to temperature?


Should be similar to a credit card. Have you ever stored a credit card in there?


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## TomT (Apr 1, 2019)

The upper limit for such RFID tags is typically 85C.


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## lance.bailey (Apr 1, 2019)

should be good if the estimate is 120F for the combo-locked box @aadams1278 guesstimated. (85C is 185F)


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## Long Ranger (Jun 1, 2018)

aadams1278 said:


> Towing with my current ICE car, I typically lock my wallet and phone inside the vehicle, and put my keys inside the black plastic storage box on the front of the trailer.


Have you had any problems with your current car keys in there? I'm guessing your current key has at least an immobilizer chip inside and possibly more complex remote lock/unlock electronics.

I'd be more concerned with leaving a phone in a hot car, but with the Tesla you have the cabin overhead protection option to address that.


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## aadams1278 (Jul 8, 2018)

Long Ranger said:


> Have you had any problems with your current car keys in there? I'm guessing your current key has at least an immobilizer chip inside and possibly more complex remote lock/unlock electronics.
> 
> I'd be more concerned with leaving a phone in a hot car, but with the Tesla you have the cabin overhead protection option to address that.


This is a good point. I don't believe the temperatures inside the center console are as hot as it would be in this small storage box in full sun, but the keyless entry on my key ring is in there.

Overall it seems like this probably won't be an issue, but I will probably try to find some small insulating bag of some kind to keep it in to give me that extra bit of confidence.


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## Ed Woodrick (May 26, 2018)

As others finally said, don't worry about it. 

Pretty much anything automotive is going to withstand any natural temperatures.


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