This is my solar powered setup. A somewhat old Pixel 6a that fell from a foot and a half (really!?), a 10w Solar setup that was around 20$ on amazon. And an old compost container I have too many of. Ill be giving it a proper 3d printed case when I get a chance (and a host of other changes) but for now this works! Its worth about 40$ in total (the phone is now worth about 21$ on the open market).
Website: https://solar.chrisco.me/
Website was made with a collection of scripts, apache2 (nginx for some reason did not install, errors), and termux. Ill open source the whole setup in a bit. Theres not much to it to be honest.
Hopefully keeping the battery at 80% will help the lifetime of the battery. I may bump it up at some point if it keeps dieing because lack of sunlight. But we shall see.
More info in the link. I couldn't get Piefed to repost from a GotoSocial link.
Is there a specific reason you strictly need static ipv6?
Android changes its IPv6 address daily. That makes it kinda hard to host anything on it. SLAAC would be fine too if it was a stable address.
Does it do that even if you set it to "use device MAC" for the wi-fi network you're on?
The exact location might depend on brand/OS, but in stock Android it's in Settings > Network & Internet > Internet > gear icon next to active wi-fi network > Privacy.
That hasn't stopped the addresses from changing on any of the devices I've tried it on.