The last two days my phone's battery has been draining at an absurd rate. It should get through the day but it's not even lunchtime and it's at 45% with only moderate usage. I checked the settings to see what's been using the battery life but it says like 3% spotify, 2% chrome, and little bits of other things in the background that do not add up to 20%, much less 55%. There haven't been any system updates in the last few days that could provoke something, and no current updates available. I just turned off location and clicked the optimize battery thing (which tells me that it's optimized and status is "great") to try to save what I can and hopefully make it through the day, but I don't know.
It's a 3 year old phone so I'm not sure if it's just the end of this battery's life or there's something in the software that's screwing it up that I can fix. But it came across suddenly and not gradually. Usually by the end of the work day with moderate phone usage I'm still in the 50s or 60s percent-wise.
Can you take it to a doctor? Factory reset?