Switch to different harware while keeping the history

[daniel_d]

Hello there,

I’m having a few Xiaomi LYWSD03MMC spread around the house. Some are running of CR2032, some off Li-Ion external battery packs. Some are running PVVX BTHome, a couple the Zigbee firmware.

I have a few SNZB-02DR2 that I prefer to the LYWSD03MMC (bigger screen, better battery, similar precision).

What would be the correct procedure to replace the thermometers (keep the same name of the device) while keeping the old historical data? What I would like is that, if I look at the history of sensor.bedroom_air_temperature after the switch, to automatically see the values gathered by both the old thermometer (until the switch) and the new thermometer (after the switch). Is this even possible?

Thanks!

PS: On another note, do you have any advice against this switch?

[Sir_Goodenough ((SG) WhatAreWeFixing.Today)]

Keep the entity_id exactly the same. The history will continue.
If you did all your automations with device_id’s you are OOL.

Put this string into a search engine for more help:

site:home-assistant.io replace hardware, keep database

Why and how to avoid device_ids in automations and scripts

Background When you start writing automations, a device trigger seems the obvious choice. Everybody knows what a device is and it comes at the top of the UI dropdown list. [Screenshot from 2025-11-20 18-37-55] It works… but it is not a the best way to start because it is storing up problems for the future. Far better to use an entity, with state or numeric_state. This topic is part of the community-driven cookbook where you can find other topics you might be interested in or might like to …

[daniel_d]

So when a device is removed the history of it’s entity ID’s will not be erased, right? Because that is my main concern.
Thank you for pointing out the automations topic. I am aware of it and already following that advice.