Hi,
I just experienced the opposite: battery life was worse than it used to be, but since I changed carrier, it seems to last twice as much.
I already had noticed that battery usage seemed to be linked to the network: the battery lasted longer in 3G than LTE:
Now I had the opportunity to live another experience when I changed carrier (no special reason to change, I just got an offer with better roaming options).
Since I changed the SIM-card, my battery lasts much longer. It is too soon to draw conclusions, but my first cycle did last 3 days (ok, I did not use my phone very much, but still, I received/sent messages, checked the newspaper, surfed a bit and called now and then). I charged this morning and still have 86% left. I hope this will last!
So I am wondering if it has something to do with network coverage, with the SIM-card itself (older SIM-cards sometimes cause trouble according to posts on this forum), or something else. I already noticed when I was abroad that my battery did last longer and I had wondered if the coverage was better.
Nothing to do with a Lineage upgrade, but I just wanted to share my experience.