iPhone Battery Health at 85%: Buy or Skip?
What iPhone battery health at 85% really means, how long it will last, and when to swap the battery instead of buying a new handset.
!iPhone showing battery health in Settings
Open Settings → Battery → Battery Health and you will see a "Maximum Capacity" percentage. On the second-hand market, 85% is the number buyers debate the most. Here is what it actually means for daily use.
What Apple's 85% figure really measures
Maximum capacity compares your battery today against the day the phone left the factory. 85% means the pack now stores 85% of its original charge — it does not mean the phone works at 85% speed.
Real-world screen-on time
On an iPhone 13 or newer at 85% health you can still expect:
- 6–7 hours of mixed use (messaging, maps, photos)
- A comfortable full working day off the charger
- No forced performance throttling from iOS
iOS only starts dialling back peak performance below roughly 80%, so 85% leaves a healthy buffer.
When to swap the battery, not the phone
A fresh Apple battery in the UK costs £65–£105 depending on the model. Book a swap when:
- Health drops under 80%.
- The phone shuts down unexpectedly in cold weather.
- You keep hitting the red at lunchtime.
That is far cheaper than replacing a £700 handset that is otherwise perfect.
Furbish Market's battery rule
Every iPhone we list ships at 85% health or higher, and the exact figure is printed on your invoice. If a unit tests lower, we replace the battery before it goes on sale — no exceptions.
Verdict
85% is a completely safe number to buy at. Skip listings that hide the figure, and remember: a £75 battery service can add two more years to a phone you already love.
