Leaving iPhone chargers plugged in overnight degrades battery health permanently

The bedtime routine destroying your device

For millions of us across the UK, the final act before switching off the bedside lamp is plugging in our iPhones. It makes perfect sense: you want to wake up to a full charge to tackle the day. However, tech experts are now warning that this universally adopted daily routine is permanently degrading your battery health.

The hidden danger of ‘trickle charging’

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When your iPhone reaches 100%, keeping it connected to the mains triggers a process known as trickle charging. The battery naturally loses a tiny bit of power, and the charger constantly tops it back up to 100%. Over a typical eight-hour sleep, this forces the lithium-ion battery into a high-stress state, generating excess heat and accelerating chemical ageing. Over time, you will notice your phone struggling to hold a charge through the afternoon.

The 80-20 rule: A battery’s best friend

If you want to prolong your iPhone’s lifespan and avoid costly battery replacements, you need to adopt the 80-20 rule. Lithium-ion batteries thrive when their charge level is kept between 20% and 80%. Pushing them to 100% or letting them drop to zero puts the cells under immense strain. Changing your charging habit to shorter bursts during the day, rather than marathon overnight sessions, is a massive time and money saver in the long run.

The hidden iOS setting you need to activate right now

Fortunately, Apple has quietly introduced a brilliant feature to combat our poor charging behaviours. By tweaking one hidden setting, you can automate battery protection without sacrificing convenience.

• Step 1: Open the Settings app on your iPhone.
• Step 2: Scroll down and tap on Battery.
• Step 3: Select Battery Health & Charging.
• Step 4: Toggle on Optimised Battery Charging (or, if you have an iPhone 15 or later, select the 80% Limit option).

This clever iOS hack learns your daily routine and pauses charging past 80% until just before you normally wake up. It is the ultimate set-and-forget daily routine hack that stops trickle-charge damage in its tracks, ensuring your iPhone stays healthier for years to come.