Why Is My iPhone Battery Draining So Quickly?

If your iPhone used to last a full day and now struggles to get past lunchtime, the cause is usually one of three things: a genuinely worn-out battery, a rogue app draining power in the background, or a software fault following an update.

Check Settings → Battery → Battery Health first. Anything below around 80% maximum capacity is a strong sign the battery itself has degraded — this happens naturally with age and charge cycles, not from anything you've done wrong.

If battery health looks fine but drain is still fast, check Settings → Battery for a breakdown of which apps are using the most power. Background App Refresh, poor signal (the phone works harder to find a connection), and location services left on for apps that don't need them are common culprits.

A drain that started right after an iOS update is often temporary — the phone reindexes files and re-optimises apps in the background for a day or two after updating. If it's still happening a week later, that's less likely to be the explanation.

If you've ruled out software causes and battery health confirms degradation, replacement is usually the fix — it's a routine repair and doesn't require replacing the whole phone.