Updated on 13 November 2026
Your iPhone charges to 100% as usual, but is the battery still in good shape? You can't tell from the battery percentage, only from the battery health: how much capacity the battery has left compared with new. Here is where to find it, what the numbers mean and when replacement is actually needed.
The short answer
- Where: Settings > Battery > Battery Health. Look at Maximum Capacity.
- 80% or higher: fine. In daily use you'll notice little difference from a new battery.
- Below 80%: Apple considers the battery consumed. Replacing it makes sense if your iPhone no longer lasts the day or slows down.
Battery health or battery percentage?
- Battery percentage is how full the battery is right now. You simply charge it to 100%.
- Battery health is the maximum capacity compared with when the battery was new. An iPhone at 85% health shows 100% when full, but lasts about 15% shorter than new.
What do the numbers mean?
- 95–100%: (almost) new.
- 85–94%: normal after one to two years of use.
- 80–84%: still very usable; with heavy use you notice it at the end of the day.
- Below 80%: consumed. iOS may show Service and limit peak performance to prevent unexpected shutdowns.
How fast a battery wears depends on the model. According to Apple, the battery in the iPhone 15 and later keeps about 80% capacity after roughly 1,000 full charge cycles; older models after about 500 cycles. On an iPhone 15 or later you'll find the cycle count under Settings > General > About.
When is replacement needed?
- Battery health drops below 80% and you no longer get through the day.
- Your iPhone shuts down with charge left, or becomes noticeably slower.
- iOS shows Service in Battery Health.
None of these apply? Then nothing needs to happen. Replacing a healthy battery is a waste: it costs money and creates unnecessary e-waste.
Make your battery last longer
- Turn on Optimised Battery Charging (or, on iPhone 15 and later, the 80% limit) in Settings > Battery > Charging.
- Avoid heat: don't charge in the sun or under a pillow, and remove a thick case if the phone gets warm while charging.
- Don't let the battery run completely flat too often.
- Keep iOS up to date; updates often improve battery management.
Battery of a refurbished iPhone from iUsed
Every refurbished iPhone from iUsed has a battery health of at least 80% on delivery. If it drops below 70% within 2 years of normal use, that is covered by the 3-year warranty; report it via the repair form. Devices in the condition Refurbished by manufacturer were refurbished by Apple itself and usually have a new battery.
Frequently asked questions
Is 85% battery health good?
Yes. Your iPhone lasts a little shorter than new, which most people hardly notice in daily use.
Should I charge my iPhone to 100%?
That's fine. With Optimised Battery Charging your iPhone waits overnight with the last percent, so the battery wears less.
Can battery health go back up?
Not really. After an update iOS may recalibrate the value, but a worn battery does not improve.