Feature request : CGM Sensor Lifespan

[ChickenSkinPoutine]

I currently use a Freestyle Libre 3+ which has a lifespan of 15 days. The 'countdown' always seems to be off by a day. I suspect this is due to the Libre 3 (not plus) have a 14 day expectancy.

May I suggest three possible solutions for this?

1. Allow the user to select which sensor they are using - with pre-defined lifespans.
2. Read the time remaining from Libre directly somehow, the phone app always displays the correct time remaining.
3. Allow the user to manually select and end date-time. Kind of a pain if you ask me.

Thanks,

Andy

[dodog]

Hi Andy, thank you for your suggestion. Unfortunately in my country, only Libre 2 sensor is available. No Libre 2 plus, or Libre 3 or Libre 3 plus. So I cannot test it.

If you have a Libre 3 plus sensor you can help me to make the integration work properly for Libre 3 plus sensors.
I created a temporary version: libre3plus which should get the information straight from Librelink API.

You can download it and replace the current one in your HA directory /custom_components/librelink/

Or you can use the Home Assistant UI, to update to libre3plus temp version like this:
Settings > Developer tools > Actions
search for action "Install update"
Targets: select target "Update Librelink"
Version: libre3plus
Click "Perform action"
Then just restart. (Do not update to 1.3.2 back)

To get the crucial information:
Open again Home Assistant Developer Tools -> States.
Find the Application Timestamp entity for your Libre device (sensor.name_surname_application_timestamp)
Send me its attributes:
Sensor product type:
Sensor lifespan days:
Sensor plus model:

The API should get this info. Then I will implement it to the librelink integration.

To return the previous version just update back to 1.3.2

[ChickenSkinPoutine]

Jozef,

As requested...

Activation date: "2026-08-02T00:31:52+00:00"
Sensor product type: 4
Sensor lifespan days: 14
Sensor plus model: false

My phone app displays 15 days remaining.
I confirmed that it is a 3 Plus model, but the phone app does not specify.
PS: Just put this new sensor on a few hours ago.

Let me know if you need anything else - always glad to help.

Andy

[dodog]

ok, thank you. I think the product type 4 will be the Libre 3 plus. My sensor is Libre 2, and shows product type 3.

Can you revert back to Librelink 1.3.2, restart, install again the same way as before the libre3plus version, restart.
Check if it now shows the correct days remaining.

[dodog]

@ChickenSkinPoutine, did you have time to try it out?

[ChickenSkinPoutine]

Sorry for the delay, you know, life...

All times here are my local times (Eastern Daylight Time GMT-4). I'm not sure exactly when the app rolls over to the next day, hence the time stamps - probably not important. The following info was gathered between 9:30pm and 10:00pm.

Applied this sensor at approx. 8:30pm on 01 Aug, became active about an hour later at 9:30pm.
By my math that means it should expire at approx. the same time on 16 Aug.
Phone app states "Sensor Ends In: 9 Days" which puts it on 16 Aug, so correct.

Allowed LibreLink Integration to "upgrade" to v1.3.2, restarted Home Assistant.
Performed manual "upgrade" to libre3plus as instructed in your first message, restarted Home Assistant.
Retrieved from States:

• Activation date: '2026-08-02T00:31:52+00:00'
• Sensor product type: 4
• Sensor lifespan days: 15
• Sensor plus model: true

Just for added confirmation, this is a clip of the Expiration Timestamp after clicking a button I created for "Sensor Expires".

Everything looks good. I will update if anything goes awry as we get close to the actual expiration date.
I do find that "Sensor Expires In 2 Weeks" a little vague. Can it be changed to "In 9 Days"?

Thanks,

Andy

[dodog]

Thank you very much for the feedback. I'm glad it's working.

Ideally, it would be the best to obtain the product type also for the Libre 2plus and the Libre 3. According to their website, the Libre 2plus also has a 15-day lifespan, and the Libre 3 has a 14-day lifespan. The official documentation doesn’t provide the sensor product type anywhere, so we’re just reverse-engineering this.

Where exactly does the message “Sensor Expires In 2 Weeks” appear?

[ChickenSkinPoutine]

In the entities for the device...

[dodog]

Oh, I don't think there's anything I can do about that. I think it's an internal Home Assistant feature that displays dates this way.

For this and other reasons, I recently created my own card. It's very simple and is used only to display the measurement, delta and expiration. I also added a few other options in case anyone needs more.
You can try it:
https://github.com/dodog/librelink-extended-card