All apple devices I’ve used in the past years tell you when the battery is degraded to the point it needs replacement. However, especially iPhones can be in sit

All apple devices I’ve used in the past years tell you when the battery is degraded to the point it needs replacement. However, especially iPhones can be in situations where the battery may still be fine for most usage, but still not be good enough to support the required power draw - for example when it’s cold outside (aka winter). I much prefer my phone to slow down in these situations over shutting down as earlier versions did.