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I just put my 2014 Challenger and 2017 Grand Cherokee key fobs in a metal cookie tin in my kitchen, not far from the inside garage door. Never had a problem. In fact, you can carry the whole tin up to the car and grab the door handle and nothing happehs. Take the lid off the tin and everything works. Also, FWIW I don't lock either vehicle while in my garage.
I lock mine in my grandmas garage....trust no one!

-Dogg
 

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I just put my 2014 Challenger and 2017 Grand Cherokee key fobs in a metal cookie tin in my kitchen, not far from the inside garage door. Never had a problem. In fact, you can carry the whole tin up to the car and grab the door handle and nothing happehs. Take the lid off the tin and everything works. Also, FWIW I don't lock either vehicle while in my garage.
Really is best to lock the car. This signals to the car's electronics the car is not going to be used for a while and the electronics can enter its lowest power mode sooner.

When I was working with car test equipment and was concerned about battery drain of the equipment when the car was off if a car was left unlocked the engine controller and other hardware was in full power mode and drawing some few amps of power. Yes, eventually the electronics does enter low power mode but in the meantime there's a pretty big draw on the battery.
 

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we're talking about the fob in proximity of the vehicle (passive entry) - not pressing any of the buttons on the fob. If the fob is within proximity of the vehicle the fob and the vehicle are in communication - this drains the battery in the fob vs. when its out of range.

for example some people might store their vehicle away and leave the fob inside (example in a secured garage) and they'll find the batteries in the fob tend to wear out quickly

Not transmitting a command from the fob by activating the buttons is what the OP was asking about
Yes, I recall now experimenting with the remote start feature of my Hellcat and I found I could activate this from some distance.

But as I mentioned in a previous post with the car locked if I do not press remote start or door unlock or trunk unlock button I get no reaction from the car until I touch the door handle.

If the car is not locked just walking around the car can have it "wake up" as the car and the key communicate.
 

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Really is best to lock the car. This signals to the car's electronics the car is not going to be used for a while and the electronics can enter its lowest power mode sooner.

When I was working with car test equipment and was concerned about battery drain of the equipment when the car was off if a car was left unlocked the engine controller and other hardware was in full power mode and drawing some few amps of power. Yes, eventually the electronics does enter low power mode but in the meantime there's a pretty big draw on the battery.
Thanks Rockster.... I always thought by locking the car it used more battery power because it had to keep the alrarm system active. I have nothing to base that on except it sounds like it could be true. I appreciate your response.... and will probably start locking the car even in the garage.
 

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I wonder if the fob boards have some residual flux or some other contaminant that is causing a current drain? I have read lots of post with guys having fob issues with pre-2015 challengers which makes me also wonder if the system is buggy to begin with? I think in 2010 or 2011? there was a recall or TSB for the WIN module replace. I would start with checking and cleaning the boards first and then make sure the replacement batteries are fresh. If the faraday bag isn't helping then it has to be something related to the fob board.

On a side note I also have a 2013 cherokee and it sits a little further away from the keys when parked in the garage and I only had to replace their batteries twice (the JGC gets used far more than the 2015 challenger).
 

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My batteries lasted 3 years and the car never gave me any warnings. I've had 2 instances of the FOB refusing to send lock/unlock, remote start, or open trunk signals, but I could drive the car with the keys in my pocket and without issue.

Since the dealer refused to diagnose this at all and just told me to replace the batteries, I have no clue if it's the FOB failing or something within the car going haywire.

If it matters, I was keeping my car locked every night, has not happened since I moved and I no longer keep the car locked.
 

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I have the “Passive Entry” system disabled via the Uconnect screen. Touching the door handle will not send a coded signal to the fob to activate it. I have to push a fob button to unlock the door but no big deal since I need a free hand to open the door anyway. I did this to prevent the car being stolen by thieves using the relay attack method.
 

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I have the “Passive Entry” system disabled via the Uconnect screen. Touching the door handle will not send a coded signal to the fob to activate it. I have to push a fob button to unlock the door but no big deal since I need a free hand to open the door anyway. I did this to prevent the car being stolen by thieves using the relay attack method.
There's an option for that?

What year is your car?
 

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Thanks Rockster.... I always thought by locking the car it used more battery power because it had to keep the alrarm system active. I have nothing to base that on except it sounds like it could be true. I appreciate your response.... and will probably start locking the car even in the garage.
Have not checked this with my Hellcat but with another car locking the car drops the power level way down and right now.

From whole amps to milli amps. The security system uses some power but it is not on all the time. It is switched on and then off every so often -- every second or so -- and it is on for just a real short time which reduces the power it consumes. And with this one car after 5 days of no use the security system would shut down some of its features to cut power usage battery drain even further.

Now I admit I never bothered to check the power usage after some time with the car not locked to see what the difference was in power consumption after the car had (finally) gone into low power mode. My interest was to ensure a car device I was working on entered low power mode and did not do anything to cause the car's engine controller to "wake up" and draw down the battery.

Even when I had a garage I always locked the car. And except in cases where I was away with the other car it never sat 5 days with no use. Generally if I have 2 cars I try to alternate between them.
 

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There's an option for that?

What year is your car?
I have a 2018 SP Charger, but think about getting a Challenger.
In my owners manual it's listed under Multimedia > Uconnect Settings.
The Setting Name is "Passive Entry — If Equipped".

From what I read, Teslas had a high theft rate because crooks were using the relay attack method to steal the cars. So Tesla did a software upgrade that gave owners the option to disable the passive keyless entry system.

Here's a demo showing how quickly someone can steal a car.

 

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I have a 2018 SP Charger, but think about getting a Challenger.
In my owners manual it's listed under Multimedia > Uconnect Settings.
The Setting Name is "Passive Entry — If Equipped".
I have a 2017 RT Plus and its in the settings menu with just a check on or remove check off.

-Dogg
 

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2016 it's Settings> Door and Locks

A Guy
 

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So, I actually just went and measured. Fobs are 17 feet from the car, and I've replaced my batteries twice in nearly 7 years. Not too bad, really.
 

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I replace the FOB battery yearly as "normal" maintenance.
 

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Here is some more info on the distance in which the FOB actively communicates with the car.

"The Passive Entry (PE) antenna units (there are a total of 5 antennas) allow the transmitter within the Radio Frequency Hub (also known as the RF Hub) to communicate via Low Frequency (LF) radio transmission with a FOB with Integrated Key (FOBIK) that is located inside the vehicle or, at most, about 2 meters (6.5 feet) horizontally in all directions around the outside of the vehicle. The RF Hub uses communication through the antenna units to wake up and challenge a FOBIK that is within range in order to authenticate whether that FOBIK is valid (programmed) to the vehicle. The RF Hub communication with the FOBIK is on 20 kilohertz using Frequency-Shift Keying (FSK) modulation."
 
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