[sho_hn]

What I do is basically:

- Put it in deep sleep

- On top of this, turn off the power domains for the RTC peripheral, RTC memory and the XTAL oscillator manually

- Use exlusively the ext1 external wakeup (ext0 requires the RTC peripherals to be powered on)

From my reading of the spec sheet, this is the best you can do on the chip.

Note that my choice of RTC also factors into the equation, the RV-3028-C7 has a significantly lower current draw than the common DS* RTC chips you see on maker-type boards.

And yeah, I bought a CurrentRanger :)

I'm very lazy about charging devices (I'm one of those people that keep their bicycle mechanical instead of going with the trend of electric shifters, because I absolutely don't want that hassle), so my goal was to maximize the number of months I wouldn't have to touch it.

[boustrophedon]

Thanks for the explanation! I didn't know it was possible to turn off the crystal at all.

Maybe I'll splurge for a CurrentRanger as well. I'm definitely on board with changing batteries as infrequently as possible.