Actual Key Fob Data

[Steve181]

As I have said in the past, in my opinion, the Lucid Air Keyfob is stylish but as poor in any other aspect as one can name, especially including battery life.

In an effort to fix mine, I made conversion Model #1 shown in the figures below. It utilizes the original keyfob with an external CR2 battery in a holder (top left in picture), which should have about 3.8 X the life of the original keyfob battery. I used a fake leather $2.95 key case that I got on Amazon. The feed-through button is from a kit of Jean buttons I also got on Amazon. This fits well in my pocket, along with a key and flashlight attached. At least I wont be stuck with a dead battery after 2 months!

In addition to all its other poor features, the push point on the original Lucid keyfob is vague and squishy. The button solves the vagueness part, and the little bit of plastic I taped on helps a little with the squishiness.

My next plan is to build a version in a smaller case (Model #2) using a small CR 2477 battery, which should give about 4.4 X Lucid's original life.

On other points, the more I drive the Air and learn about it, the more I love it. In about 2 months, I have gone from hating any kind of regeneration, to craving it (e.g. when the battery is full and I dont get any.)

BUT, the key fob is an insult to functional design. Lucid should take steps to give us keyfob with buttons, that lasts a year (like on the Gravity?) or any cheap econo-box rental car.

Cheers,

Steve

 

[Buffalo Bob]

For what it's worth... My wife, who never drives the car, keeps her fob in a faraday bag in her purse just in case she wants to get in the car when I'm not around. (She once got stranded outside the AMP1 facility while I was doing a factory tour. Serves her right for passing that up, with Peter running the show like a kid in a candy store!!! ) After close to a year of sitting in that bag, the fob worked fine, so I wonder if there really is all that much drain just while sitting in the bag. Similar for me with my fob, which sat in the bag for months until it was time for my annual service. [Perhaps noteworthy... Our bagged fobs spend little time in any close proximity to the car.]

 

[borski]

This is why I don’t use the fob. Just mobile key with the key card as a backup in my wallet.

I’ve played with this monstrosity before. I have no desire to fob again.

 

[Buffalo Bob]

This is why I don’t use the fob. Just mobile key with the key card as a backup in my wallet.

I’ve played with this monstrosity before. I have no desire to fob again.

Same here. I have never had to use the key card as a back-up either. I don't even have an iPhone, and the car still accepts me!

 

[borski]

Same here. I have never had to use the key card as a back-up either. I don't even have an iPhone, and the car still accepts me!

Yeah, I've never used the keycard other than to test it. My mobile key works fine. Of course if I stopped carrying the keycard that's the day it would fail, so why tempt fate; it just lives in my wallet.

 

[Steve181]

For what it's worth... My wife, who never drives the car, keeps her fob in a faraday bag in her purse just in case she wants to get in the car when I'm not around. (She once got stranded outside the AMP1 facility while I was doing a factory tour. Serves her right for passing that up, with Peter running the show like a kid in a candy store!!! ) After close to a year of sitting in that bag, the fob worked fine, so I wonder if there really is all that much drain just while sitting in the bag. Similar for me with my fob, which sat in the bag for months until it was time for my annual service. [Perhaps noteworthy... Our bagged fobs spend little time in any close proximity to the car.]

B.B.

Others have also reported success with the Fraday shield, but in my tests far away from the car fob, battery drain continues above standby at a high pulsed level. I had assumed that the Fob sends out a (battery draining) burst every second or so to see if the mothership responds. That correlates with my measurements, and the info from the chip specs. If correct, that would say the Faraday bag has no impact. But something else is going on. Thus, a goal for me now is to undertsand exactly how the fob protocol works.

If there are knowledgeable folks reading this here are some questions:

1- Exactly what is the fob protocol? (Its part of BLE I think.)

2 - Can the fob be cloned?

3 - Has anyone ever opened the fob to expose the RF board?

Thanks much! Steve

 

[Buffalo Bob]

B.B.

Others have also reported success with the Fraday shield, but in my tests far away from the car fob, battery drain continues above standby at a high pulsed level. I had assumed that the Fob sends out a (battery draining) burst every second or so to see if the mothership responds. That correlates with my measurements, and the info from the chip specs. If correct, that would say the Faraday bag has no impact. But something else is going on. Thus, a goal for me now is to undertsand exactly how the fob protocol works.

If there are knowledgeable folks reading this here are some questions:

1- Exactly what is the fob protocol? (Its part of BLE I think.)

2 - Can the fob be cloned?

3 - Has anyone ever opened the fob to expose the RF board?

Thanks much! Steve

Hi, @Steve181:

I'm not sure what I can do to help with your analysis, and hope that what I reported is not leading you astray. For all I know, our FOB batteries had just enough juice to open the doors the one time I tried, and a second click would have yielded nothing. Is there any way to reliably measure a new battery's SOC, such that one could install it, put the fob away, wait a month or so, and then measure its SOC again?

I also suspect that not all faraday bags and batteries are created equal. Especially when buying online, I'll bet there is a lot of variability in their qualities, which could significantly impact your analysis. (With things like batteries, I'm not even sure you can trust that the manufacturer is who they say they are.)

Last, if the faraday bags is indeed lacking, I understand that close proximity to the vehicle can have a big impact, as the fob and car keep communicating back and forth. Since we live several floors above our car in a concrete and steel building, the fob may reach out, but (faraday bag or not) it won't be hearing back from the car.

It is an odd situation, and frankly makes me wish that automatic door open/close was simply not a fob feature. That way, I don't see the need for any battery-draining communication unless a button is pushed.

Bob

 

[ColonelBadger]

I use a FOB and don't use a faraday bag. Batteries in it are approximately 4 months old and still going fine. Only reason I don't use the Mobile key is the constant opening closing every time I go in the garage with my cell in my pocket (I always keep my phone on me).

 

[Lucken]

This is why I don’t use the fob. Just mobile key with the key card as a backup in my wallet.

I’ve played with this monstrosity before. I have no desire to fob again.

Fob bigot!

 

[Buffalo Bob]

I use a FOB and don't use a faraday bag. Batteries in it are approximately 4 months old and still going fine. Only reason I don't use the Mobile key is the constant opening closing every time I go in the garage with my cell in my pocket (I always keep my phone on me).

Since I exclusively use my mobile key, I just toggle my Bluetooth off when I am puttering about near the car.

 

[DeaneG]

...2 - Can the fob be cloned?

No - if it could be cloned, then every bad guy would be doing it. Instead, they have to use a relay attack.

I don't have any issues at all with the fob. I keep it in a faraday bag when I'm not driving the car, though I'm not sure if that is still necessary. It's been absolutely fine.

 

[Steve181]

I was not able to find the exact protocol, but did find this:

"Advertising and discovery
BLE devices are detected through a procedure based on broadcasting advertising packets. This is done using 3 separate channels (frequencies), in order to reduce interference. The advertising device sends a packet on at least one of these three channels, with a repetition period called the advertising interval. For reducing the chance of multiple consecutive collisions, a random delay of up to 10 milliseconds is added to each advertising interval. The scanner listens to the channel for a duration called the scan window, which is periodically repeated every scan interval."

I also found the table below, and studied the data sheets from 2 manufacturers of BLE chips which show about 5 ma (5000 microamps) of transmitter power draw on the lowest power mode.

My conclusions thusfar:

The key fob ADVERTISES itself to the mother ship (Car) every X seconds, during which the keyfob transmitter draws about 5 ma (5000 microamps) from the CR2032 keyfob battery. According to the table below, the more often it does that (shorter advertising interval , the shorter the battery life, whcih could be in months depending on the advertising rate. I will need an oscilliscope to measure that, unless someone listening already has done that or has the number.

I dont see how the Faraday bag could alter that, UNLESS the keyfob slows its advertising rate if it does not detcet the mothership after a certain time. That would be a very good idea.

My current hope is that I can build a new fob with a larger battery, using the existing electronics, and a real click switch.

LUCID: A great car held back by an inferior keyfob.

Cheers

 

[segbrk]

3 - Has anyone ever opened the fob to expose the RF board?

Haven’t figured out how to open it without destroying the housing, but there are photos if you look up the FCC ID.

Usual practice with these things is to reduce the wakeup frequency after not hearing from the car in a while and not moving (measured with an accelerometer or something in the fob). My fob battery is still fine after 7 months of mostly sitting on a shelf far away from my car.

 

[Cosmo Cruz]

Since I exclusively use my mobile key, I just toggle my Bluetooth off when I am puttering about near the car.

I like to listen to podcasts, so I turn the Lucid app off when I am in and around the car.

Generally only turn the app on when I'm fast charging and need to watch the SOC so I know how much time I have for a walk.

I use the fob. I have no battery issues with it. Door handle presents before I can touch it.

 

[Steve181]

Hi, @Steve181:

I'm not sure what I can do to help with your analysis, and hope that what I reported is not leading you astray. For all I know, our FOB batteries had just enough juice to open the doors the one time I tried, and a second click would have yielded nothing. Is there any way to reliably measure a new battery's SOC, such that one could install it, put the fob away, wait a month or so, and then measure its SOC again?

I also suspect that not all faraday bags and batteries are created equal. Especially when buying online, I'll bet there is a lot of variability in their qualities, which could significantly impact your analysis. (With things like batteries, I'm not even sure you can trust that the manufacturer is who they say they are.)

Last, if the faraday bags is indeed lacking, I understand that close proximity to the vehicle can have a big impact, as the fob and car keep communicating back and forth. Since we live several floors above our car in a concrete and steel building, the fob may reach out, but (faraday bag or not) it won't be hearing back from the car.

It is an odd situation, and frankly makes me wish that automatic door open/close was simply not a fob feature. That way, I don't see the need for any battery-draining communication unless a button is pushed.

Bob

Thanks again Bob. The variabity we are hearing about may also be caused by a change in chip vendors. From the table I posted, different chips have different lives. I also wonder if they lower the advertising rate according to not hearing the mothership. That would be a terrific scheme to increase battery life (and justify the Faraday bag.) Fob battery SOC could be roughly measured from its battery voltage. FYI - I try to stick with Energizers from Amazon.

I wish we could hear from LUCID with real info and ideas.

 

[Steve181]

Haven’t figured out how to open it without destroying the housing, but there are photos if you look up the FCC ID.

Usual practice with these things is to reduce the wakeup frequency after not hearing from the car in a while and not moving (measured with an accelerometer or something in the fob). My fob battery is still fine after 7 months of mostly sitting on a shelf far away from my car.

Thanks. Good info!

 

[Steve181]

I decided that I need to keep the keyfob in my pocket every day, just like every other keyfob I ever used, and I don't want to walk around with a Faraday bag. Hence, I am starting to build my much smaller keycase based fob holder. Here is the battery I just ordered - a CR2477. It will have over 4 times the life of the CR2032 I am now using. The size is exactly that of 5 stacked quartres. I'll send pictures of Model 2 when done.

 

[rfc805]

I hadn't had issues with this for the first few months, but - my fob battery has died twice (fully) in the last month.

Ugh.

Hey Lucid - can you make it so we can use a mobile key but not use proximity lock/unlock? I wouldn't mind it if (it worked) and I could just press the door handles but still not use proximity locking which I hate.

 

[segbrk]

Hey Lucid - can you make it so we can use a mobile key but not use proximity lock/unlock? I wouldn't mind it if (it worked) and I could just press the door handles but still not use proximity locking which I hate.

You already can?
Set up mobile key and disable proximity lock/unlock in the car’s settings.

 

[Steve181]

I somehow have my proximity lock/unlock turned off - I think by a switch on the lower screen. I found the instructions in the manual.

I do not have the mobile key on my Samsung Note 9 phone set up, since it is too old to use the Lucid Ap. The only way in/out right now is to HARD push the invisible button on the key fob or push in the door handles. To open the trunk remotely, I have to HARD PUSH the Morse Code letter A on the keyfob and get the timing just right.