Long life battery?

Any ideas of long life battery hack for Ruuvitag? I want to put a tag inside the house structures to keep track of the temperature and would like to have several years of operation time.

We use a custom firmware for this kind of use-cases. You can flash https://github.com/ruuvi/ruuvi.firmware.c/releases/download/v3.31.2-RC1/ruuvitag_b_armgcc_ruuvifw_longlife_v3.31.2-RC1_dfu_app.zip with nRF Connect, it broadcasts once per 10 seconds if I recall correctly.

Because the tag broadcasts rarely, it’s not practical to use it without Ruuvi Gateway or other always-scanning device and it’s very difficult to connect to it afterwards for reading tag logs or for update. You can update the tags as long as you have physical access, but once they’re in walls updating is no longer practical.

We have not tested that version extensively, and it’s not an officially supported release. We provide it anyway for users who want to try it out.