the “dark” in the manual is most likely referring to the backlight, not the information on the screen.
No worries, Suunto’s sports watches are designed to always show information (watch face in standby). Different than smart watches like the apple watch (or the Suunto 7), this dows not cause additional battery consumption and is the way it is supposed to be.

Suunto 5.png

This is my battery life. HR 24/7 enabled, sleep tracking enabled, bluetooth notifications disabled, vibration disabled, tones in button off mode. I did use GPS for 10minutes. I had one indoor activity with HR for 20 minutes. Once per day i synchronised with suunto app. Every day a played with watch around 5-10 minutes. Backlight was off 99% of time.

So it looks i was too rush. Battery drop was fast only above 80% of battery. At around 80% i did soft reset. Maybe it helped to stop rapid battery drain.

I am very satisfied with result.

@jon-murua
What is power saving in Spartan Ultra?
And next tests to do : confirm the first one (full power and watch in pocket), and full power watch on backpack. 😊

GPS and OHR worked really well : https://beta.quantified-self.io/user/88tGXoxa0YOtAw07abZo8jK8mN93/event/3cPQA91MbTn2CvY9nukbwvqsE5BRQodXKmw79U2Pe41tGmy

Moved to Spartan area as the main “suggestion” is watch related