Just a wild guess, but do you normally wait to charge the battery until it's down to 10% or until the tab tells you to charge it? That's the easiest way to give it a short life. (Which sounds like your problem - your battery is dying.) See the second chart in
Battery University - How to Prolong Lithium-based Batteries and figure it out. (Conditioning the battery - a full charge, then use it until it tells you to charge it, repeat 2 more times, then
never letting ig fall below 40% [50% is the sweet spot] will give you a lot more lifetime. [You'll see claims that lithium batteries don't have to be conditioned. That's true - if they're fairly new. If the battery has been sitting on a few shelves since it was made, and it's been 6 months since it was charged, you should, or you'll shorten its life. Since you can't know its history, condition any new battery, and any battery that's been sitting for more than a few months.] And store batteries
disconnected and at about 40% charge.)
You'll see a whole battery course on the left side of the site at the link. Cadex makes battery analysis products, so they know a little about batteries.
(BTW, you waited 15 minutes to make your second post. We don't mind helping, but this isn't a paid job. [If it were, I could afford a new flagship phone every week.] We're just people like you, people who use Android phones, who know the answers to some of the questions being asked. If we take a few hours to get to your question, or to get on line at all because we're playing with the kids or mowing the lawn, you'll just have to be patient. A couple of days without an answer? Sure, bump the post. Fifteen minutes? Fifteen minutes ago I was answering another post [and meaning to get up, after every answer I post, to get some of the coffee I made while it's still fresh - which is where I'm headed now, so the poster of the next question I'm going to look at will have to wait another 2 minutes].)
