Spotlight Cam Plus - Understanding Solar charging status

I have my Spotlight Cam Plus connected to a Ring solar panel. Once the charge gets to about 85% on the App, solar charging appears to kick in and bring it back up to 100%. This seems to work fine but is not what the Ring documentation suggest will happen - Ring suggest that Spotlight batteries connected to solar panels are only charged to around 80% to preserve battery life. So what is supposed to happen?? Also the battery icon on the App always shows the battery with charging 'lightning bolt' plus sun icon which again according to ring means the panel is charging my device; it's clearly not charging continously but only when battery drops to around 85%. Surely the battery icon should only show just sun & battery icon but not lightning bolt? Again no big deal but just annoying....