Nothing ages an iPhone faster than a worn battery. The good news: battery chemistry is predictable, and a few habits will keep your battery health above 90% far longer than average.

Heat is the real enemy

Lithium batteries degrade fastest when hot. Avoid charging in direct sunlight, take the case off during fast charging if it gets warm, and never leave the phone on a car dashboard.

Use the built-in charging tools

Optimized Battery Charging learns your routine and pauses at 80% overnight, finishing just before you wake. On recent iPhones you can also set a hard 80% charge limit — the single most effective setting for long-term health if your daily use allows it.

Finally, don’t obsess over the percentage. Batteries are consumables; even well-treated ones wear. But with these habits, yours will wear years slower.