This is the smartwatch I own. True netrunners know that the tech we wear on (or under) our skin is a prime entry vector for ever hungry megacorps to bleed the pulsing data from our digital veins, so having a wearable I have full control over is of paramount importance. I can flash it with new firmware whenever I want, the multiple open source options available are all an open book to any hacker worth their cyberlinguistic salt, and I can know for a fact that it won’t phone home with my location or other data to any corporation behind the scenes. If we are all going to be cyborgs integrating technology onto and eventually into our bodies, better to control that tech ourselves!
About 6-7 days. I haven’t noticed myself consistently charging my watch on the same day (like, if I was charging every Sunday or something), but I just checked GadgetBridge (the companion app for Android) and it has a chart showing my battery go from 96% down to 12% over a 6-day period, when I then plugged in my watch to charge it again. The battery icon changes color when it hits 15% so I usually plug it in at that point rather than letting it drain completely.