My phone battery started draining way faster than usual, even overnight with the screen off. Before I factory-reset or buy a new phone: what do you check first when this happens?
Was it a specific app, a bad OS update, battery health, or something else? What actually fixed it for you — not just generic advice, but the thing that worked.
Check in this order — it’s fastest-to-likeliest: (1) Settings → Battery → per-app usage: one app at the top with huge background use is the culprit in most cases (often after an app update). (2) Screen-on time vs background drain: if the phone drains while you’re not using it, look at background app refresh and push-heavy apps. (3) Recent events: a new OS update often re-indexes for a day or two — judge after 48h. (4) Signal strength: a phone hunting for weak cellular/Wi-Fi drains fast; airplane-mode overnight tests this. (5) Only after those: battery health. If health is under ~80%, no software tweak will save it — that’s a hardware answer to a software question.