Battery health is one of the most-asked-about topics when buying a refurbished iPhone — and for good reason. It affects how long your phone lasts between charges and how it performs over time. The good news: it's simple to understand once you know what the number means. Here's everything to know before you buy a certified refurbished iPhone.

What is iPhone battery health?

Every rechargeable battery wears slightly with use. Apple measures this as Maximum Capacity — a percentage showing how much charge your battery holds now versus when it was new. A brand-new iPhone reads 100%. As it's charged over months and years, that number gradually drops. It's completely normal, and it's the single best indicator of a battery's condition.

What's a good battery health number?

As a rule of thumb, 80% or higher is considered healthy and gives you a full day of normal use. Between roughly 80% and 90% is typical and perfectly good for everyday life. Below 80%, you may notice shorter runtime and could eventually want a battery replacement. For a refurbished iPhone, a healthy capacity plus a warranty is exactly what you're looking for.

How to check your battery health

Go to Settings → Battery → Battery Health & Charging. You'll see your Maximum Capacity percentage. It's the first thing worth checking on any phone — new or refurbished — and takes five seconds.

How to make your battery last longer

• Turn on Optimized Battery Charging (Settings → Battery) to reduce wear from overnight charging.
• Avoid extreme heat — high temperatures are the biggest enemy of battery life.
• Skip constant 0% and 100% — topping up in the middle is gentler on the battery.
• Use a quality charger — a certified cable and block charge safely and protect long-term health.

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Frequently asked questions

What battery health is good for a refurbished iPhone?

80% or higher is the healthy benchmark, giving you a full day of normal use. Every Strictli iPhone battery is tested during certification and backed by our 1-year warranty.

How do I check battery health?

Settings → Battery → Battery Health & Charging shows your Maximum Capacity percentage. Check it any time.

Can I replace an iPhone battery later?

Yes — batteries are serviceable, so even years down the road a replacement can restore full runtime. It's one reason iPhones last so long.

Does a lower battery health mean a bad phone?

Not at all — anything 80%+ is healthy for daily use, and the price reflects it. Pair a great value with our warranty and you're in good shape. Browse certified iPhones.

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