How low is a low battery

[Chuckeee]

When you get a low battery warning on an AirTag, how long do you have until the battery actually dies?

I have gone 6 weeks after get a low battery warning and then changed the battery “just in case”. Was I pushing my luck or does a “low battery” on an AirTag means it is still good for several months?

 

[YukiseKimi]

It can run on still for months but with limited functionalities. I put mine in a storage with my road bike and I had the low battery warning for several months now. I cannot sound the AirTag and it seems to update itself less frequently over time.

 

[arw]

While it cannot answer the main question, there are some interesting findings regarding AirTags in the link below.
It also shows why power consumption varies depending on the situation/mode the AirTag is in.
Key facts:

• Sleep current consumption of 2.3µA gives over 10 years of potential battery life
• Playing sound uses >3000x more power than being asleep, around 8mA
• nRF needs at least ~1.9V battery voltage to boot up

Spoiler: More

• Updates BLE address and public key once a day at 04:00am
• Updates last byte of advertisement data every 15 minutes
• Goes into a lost mode exactly 3 days after being away from its owner’s device
• Makes noise once every 6 hours while in lost mode and movement is detected
• Samples the accelerometer every 10 seconds when waiting for movement
• Samples the accelerometer every 0.5 seconds once motion is detected, for 20 seconds
• Transmits BLE advertisement every 2 seconds when away from its owner’s device
• BLE connection interval of 1 second when near its owner’s device

Apple AirTag Reverse Engineering - Adam Catley

adamcatley.com

 

[erihp]

While it cannot answer the main question, there are some interesting findings regarding AirTags in the link below.
It also shows why power consumption varies depending on the situation/mode the AirTag is in.
Key facts:

• Sleep current consumption of 2.3µA gives over 10 years of potential battery life
• Playing sound uses >3000x more power than being asleep, around 8mA
• nRF needs at least ~1.9V battery voltage to boot up

Spoiler: More

• Updates BLE address and public key once a day at 04:00am
• Updates last byte of advertisement data every 15 minutes
• Goes into a lost mode exactly 3 days after being away from its owner’s device
• Makes noise once every 6 hours while in lost mode and movement is detected
• Samples the accelerometer every 10 seconds when waiting for movement
• Samples the accelerometer every 0.5 seconds once motion is detected, for 20 seconds
• Transmits BLE advertisement every 2 seconds when away from its owner’s device
• BLE connection interval of 1 second when near its owner’s device

Apple AirTag Reverse Engineering - Adam Catley

adamcatley.com

When you get a low battery warning on an AirTag, how long do you have until the battery actually dies?

I have gone 6 weeks after get a low battery warning and then changed the battery “just in case”. Was I pushing my luck or does a “low battery” on an AirTag means it is still good for several months?

just replace it now. cr2032s are what, $.50?

you -really- dont want to see that the speaker or uwb can't be enabled because the battery is too low.

do you want to be able to reliably track and find the thing you just lost and critically need? if its not that important to you, maybe it doesn't even need a tag.