Key Fob Battery Life after Update to latest firmware

[brokebit4096]

Hey Folks - Curious, are you still seeing issues with key fob battery life after the most recent updates? Our Gravity is on 3.4.1 and the key fob is on 2.35.08 and we're only getting about 10 days from a fresh key fob battery.

 

[blagar1000]

Hey Folks - Curious, are you still seeing issues with key fob battery life after the most recent updates? Our Gravity is on 3.4.1 and the key fob is on 2.35.08 and we're only getting about 10 days from a fresh key fob battery.

Did you replace the key fob battery after the update, as suggested by the release notes, or before it?

 

[brokebit4096]

@blagar1000 I did replace the battery as suggested with a fresh one after the update.

Quick update: I just removed the battery, and it's reading 3V, which is nominal. So that makes me think something else is going on. I replaced the battery again just now, and the key is working. So, I'm at a loss. Called service and let them know what's going on. They didn't have any viable suggestions or ideas other than replacing the battery. In the past, when we had issues, and I popped the battery, the voltage was closer to 2.4 or 2.5v.

 

[Gravitas]

Hey Folks - Curious, are you still seeing issues with key fob battery life after the most recent updates? Our Gravity is on 3.4.1 and the key fob is on 2.35.08 and we're only getting about 10 days from a fresh key fob battery.

Same Gravity (3.4.1) and Key Fob (2.35.08) versions and no issues auto opening and closing doors on approach/departure.
Granted, I've never had Key Fob issues since Gravity was delivered on 12/19/2025 with v3.3.20.

In fact, I am still using same battery that came with Key Fob on 12/19/2025.
In the beginning I used to walk around with my Key Card for emergencies.
Left Key Card at home, and now walk around with an extra battery, just in case.

 

[DeaneG]

Many devices I've owned report low battery at 3.0V. I don't know about Gravity.
A new cell should read about 3.3V.

 

[illopp00]

When I did my fob update I measured my battery at 2.9V, it's still mostly responsive and not causing any issues but I can tell it's taking longer to turn the car off when you walk away. I have a bunch of stuff to save for a service visit so trying to get it to last a couple more weeks.

 

[bicycleguy]

Hey Folks - Curious, are you still seeing issues with key fob battery life after the most recent updates? Our Gravity is on 3.4.1 and the key fob is on 2.35.08 and we're only getting about 10 days from a fresh key fob battery.

Please carefully read my post at: resolved! I could have said a lot more about what I have observed but don't want to be wrong and or cause people more worry.

The main issue is that when the fob and the car are communicating continuously the battery can't keep up. The Gravity (3.4.1) and Key Fob (2.35.08) combo updates main accomplishment was to limit that continuous communication and lower its volume. Basically in many situations the car tells the fob to go take a nap and in others the fob does that on its own. If someone is walking with fob in pocket and within ~50ft of the gravity they can still probably drain the battery down in ~10 days.

The other issue I didn't mention is the fob batteries voltage is a somewhat poor indicator of its state of charge. If you measure a battery at 3.00V first thing in the morning walk to say 25 feet from the car and linger for 2 minutes and then measure the battery it probably dropped to 2.96V. If you measure the battery voltage immediately after it fails to open the car you may see something below 2.80V. If you leave that battery out of the fob for 5 minutes and measure it again it may climb to 2.86V and another 5 minutes 2.87V and the next morning 2.95V. A fresh battery won't drop so fast and will rise quicker. Techies will note that a proper battery tester for these batteries would put a load on it while measuring.

I measured the Malak batteries in the visor of the Gravity and they all measured ~3.2V. Put one in the fob for a normal day and it dropped to 2.95V so I wasn't to hopeful, but I have been using that same battery for 8 days since the update and it oscillates around 2.97V. So it's doing ok.

 

[brokebit4096]

Maybve I'm taking this too far:

So, I did some basic power analysis on the keyfob. When it's "awake," and the car is about 40ft away, it seems to ping once a second. When it does that, it draws up to 48mA.

After about one minute, it seems to go to sleep. At which point I see spikes of current draw of about 9mA on average every one to two seconds.

On the spectrum analyzer, you can clearly see a beacon every second when the key is awake, right at 2.4Ghz. So, that is probably some sort of Bluetooth beaconing. I looked up the FCC ID for the fob, and it appears to support ultra-wideband communications at 6.5 GHz, 7.5 GHz, and 8.5 GHz. I should have some time next week to try to analyze that and see if there is any TX on those bands when it's sleeping. The next step is to do the same analysis on my Subaru fob, which seems to last forever.

I also noticed it does not take much to "wake" the key. Simply tapping on my desk was enough to wake it.

I let the fob sit for an hour and tracked its power consumption. Based on that, it should last years. (~70 µWh per hours sleeping) So, at some point, when I'm not looking, something is draining the battery.

I've also watched when the car wasn't home, and it doesn't seem to matter. The pattern is the same. This is with the latest firmware on the fob and car.

My battery seems to die within 7 to 10 days.

 

[brokebit4096]

Also, in case anyone is curious, the key fobs are not made by Lucid. They buy them from a German company called Marquardt GmbH.

https://apps.fcc.gov/eas/GetApplicationAttachment.html?id=7888539

 

[hwy17er]

Maybve I'm taking this too far:

View attachment 36829
View attachment 36826

So, I did some basic power analysis on the keyfob. When it's "awake," and the car is about 40ft away, it seems to ping once a second. When it does that, it draws up to 48mA.

View attachment 36827

After about one minute, it seems to go to sleep. At which point I see spikes of current draw of about 9mA on average every one to two seconds.

View attachment 36828

On the spectrum analyzer, you can clearly see a beacon every second when the key is awake, right at 2.4Ghz. So, that is probably some sort of Bluetooth beaconing. I looked up the FCC ID for the fob, and it appears to support ultra-wideband communications at 6.5 GHz, 7.5 GHz, and 8.5 GHz. I should have some time next week to try to analyze that and see if there is any TX on those bands when it's sleeping. The next step is to do the same analysis on my Subaru fob, which seems to last forever.

I also noticed it does not take much to "wake" the key. Simply tapping on my desk was enough to wake it.

I let the fob sit for an hour and tracked its power consumption. Based on that, it should last years. (~70 µWh per hours sleeping) So, at some point, when I'm not looking, something is draining the battery.
View attachment 36830

I've also watched when the car wasn't home, and it doesn't seem to matter. The pattern is the same. This is with the latest firmware on the fob and car.

My battery seems to die within 7 to 10 days.

I concur I've been clicking open/locking my Subaru since 2013 with the same key fob/same battery; never failed once in 13yrs!

yes, yes, I know: it's not as secure as the Gravity fob (but then who would steal an old Outback?...millennials don't want it, it's a stick shift )

 

[RandomDesign]

FWIW I keep mine in a faraday box and haven't had to change my battery since I put a new one in the fob the day I took delivery on 12/19 (knowing the stock battery would likely suck). I also have the auto lock/unlock disabled and just use the buttons for now.

I went for a brand I've used before on Amazon called Retail Digitals because I know they don't use the bitter coatings that interfere with some electronics (like Apple's AirTags and CR2032s with the coating).

 

[BS8899]

Maybve I'm taking this too far:

View attachment 36829
View attachment 36826

So, I did some basic power analysis on the keyfob. When it's "awake," and the car is about 40ft away, it seems to ping once a second. When it does that, it draws up to 48mA.

View attachment 36827

After about one minute, it seems to go to sleep. At which point I see spikes of current draw of about 9mA on average every one to two seconds.

View attachment 36828

On the spectrum analyzer, you can clearly see a beacon every second when the key is awake, right at 2.4Ghz. So, that is probably some sort of Bluetooth beaconing. I looked up the FCC ID for the fob, and it appears to support ultra-wideband communications at 6.5 GHz, 7.5 GHz, and 8.5 GHz. I should have some time next week to try to analyze that and see if there is any TX on those bands when it's sleeping. The next step is to do the same analysis on my Subaru fob, which seems to last forever.

I also noticed it does not take much to "wake" the key. Simply tapping on my desk was enough to wake it.

I let the fob sit for an hour and tracked its power consumption. Based on that, it should last years. (~70 µWh per hours sleeping) So, at some point, when I'm not looking, something is draining the battery.
View attachment 36830

I've also watched when the car wasn't home, and it doesn't seem to matter. The pattern is the same. This is with the latest firmware on the fob and car.

My battery seems to die within 7 to 10 days.

Great work!

But, shouldn't Lucid have already done all these analyses? It is particularly sad and unforgivable given similar experience on the Air FOB. In the Air-case, Lucid placed the blame on the FOB manufacturer and cited a contract they couldn't get out of with the FOB manufacturer. Honestly, that sounded like a crock of SH*T!

Is Lucid management dealing withs customers on the up-and-up?!

To me, the locking/unlocking problems is the #1 safety concern. I will not let my family or friends drive the Lucid alone in fear they might get stranded somewhere in the middle of the night and can't get in the car.

Am I exaggerating? Nope, that happened to me one month I got my Lucid air, in December 2022.

 

[bicycleguy]

Maybve I'm taking this too far:

Ya !! finally someone I can commiserate on this fob stuff. Here's my setup:

3D printed a little battery substitute to make measurements easier. I'm using a size 123 lithium so less battery issues. The Current ranger device converts nA, uA or mA to mV for measuring with a normal voltmeter or the oscilloscope. I'll post some more but I have to go do Valentines Day (tasks )

 

[brokebit4096]

FWIW I keep mine in a faraday box and haven't had to change my battery since I put a new one in the fob the day I took delivery on 12/19 (knowing the stock battery would likely suck). I also have the auto lock/unlock disabled and just use the buttons for now.

I went for a brand I've used before on Amazon called Retail Digitals because I know they don't use the bitter coatings that interfere with some electronics (like Apple's AirTags and CR2032s with the coating).

We think alike. I just bought a faraday box and I'm keeping our second fob in there. Started that experiment a few days ago, so we'll see. TBH, it's 2026 and this is a $100k+ car. This should work. Plenty of other cars have proximity unlock/lock and no issues.

 

[brokebit4096]

Great work!

But, shouldn't Lucid have already done all these analyses? It is particularly sad and unforgivable given similar experience on the Air FOB. In the Air-case, Lucid placed the blame on the FOB manufacturer and cited a contract they couldn't get out of with the FOB manufacturer. Honestly, that sounded like a crock of SH*T!

Is Lucid management dealing withs customers on the up-and-up?!

To me, the locking/unlocking problems is the #1 safety concern. I will not let my family or friends drive the Lucid alone in fear they might get stranded somewhere in the middle of the night and can't get in the car.

Am I exaggerating? Nope, that happened to me one month I got my Lucid air, in December 2022.

Agreed. My wife got stranded the other night, and I had to go pick her up. For now, she is keeping one of the RFID cards in her purse as plan B. I suspect Lucid is in a bind with the mfg of these fobs and can't easily switch out. Hopefully, they can get the phone key stuff working on the gravity. I used to have a Tesla, and the phone key was great. I never thought about locking / unlocking.

 

[brokebit4096]

Ya !! finally someone I can commiserate on this fob stuff. Here's my setup:
View attachment 36832
3D printed a little battery substitute to make measurements easier. I'm using a size 123 lithium so less battery issues. The Current ranger device converts nA, uA or mA to mV for measuring with a normal voltmeter or the oscilloscope. I'll post some more but I have to go do Valentines Day (tasks )

Nice setup and good approach. I'm really curious what is happening on the ultra-wide-band freq and I think we need to find a way to log the data over long periods of time. My current theory is that where we keep our keys is in a gray area... not too far away from car but not too close. Would love to see the firmware. I might try to log power consumption while it's in a Faraday box too.

 

[bicycleguy]

Here's my bandaid solution to the faraday box:
BAND-AID Brand Anniversary Tin edition

By the way since 3.4.1 and 2.35.08 I don't need it any more. As long as I don't jostle the fob the consumption is the same as faraday box even with auto lock/unlock enabled. My latest testing was to determine how much movement caused the fob to wake up.

Any time you do one of the following the fob will wake up for at least ~60 seconds. (what that means later, woke is not all that bad !)
1. Try to pick it up as carefully as possible.
2. Put the fob in your pocket and try to walk.
3. With the fob sleeping in your pocket because you stood there motionless for sixty seconds, try to start walking.
4. With the fob on the table pound once like Cozmo in Moon Struck.
5. Remove and reinstall the battery, even if done without jostling.
6. Almost forgot, press any key of course!

 

[wowbagger]

Hey Folks - Curious, are you still seeing issues with key fob battery life after the most recent updates? Our Gravity is on 3.4.1 and the key fob is on 2.35.08 and we're only getting about 10 days from a fresh key fob battery.

I keep my key relatively close to my car but put it in a Faraday box to prevent issues. Works very well and keeps all of it safe.

 

[socktucker]

We think alike. I just bought a faraday box and I'm keeping our second fob in there. Started that experiment a few days ago, so we'll see. TBH, it's 2026 and this is a $100k+ car. This should work. Plenty of other cars have proximity unlock/lock and no issues.

Compromise Anything

But for real, what a sorry state of affairs these guys are in.

 

[Saksak]

I’m still on my original battery at 7 weeks and counting. Five weeks on 3.3.20 and two weeks on 3.4.1.

I’ve kept the key fob in my pants pocket continuously, including on daily walks with my dog.