iPhone Battery Health Explained: What Percentage Should You Buy?
When shopping for a used iPhone, battery health is the single most important spec to check. A degraded battery means shorter battery life, slower performance, and potentially unexpected shutdowns. Here is everything you need to know.
What is iPhone Battery Health?
iPhone battery health (found in Settings > Battery > Battery Health) shows the maximum capacity of your battery compared to when it was new. A brand new iPhone shows 100%. Over time, chemical aging reduces capacity.
Battery Health Percentage Guide
| Battery Health | What It Means | Recommendation |
|---|---|---|
| 100% | Brand new or recently replaced battery | Excellent |
| 90-99% | Minimal degradation, like-new performance | Great choice |
| 85-89% | Slight degradation, still reliable all-day battery | Good choice |
| 80-84% | Noticeable reduction, may need afternoon charge | Acceptable for budget buyers |
| 75-79% | Significant degradation, battery replacement recommended soon | Only if price is very low |
| Below 75% | Poor battery life, performance throttling likely | Avoid or replace battery |
How Does Battery Health Affect Performance?
Apple includes performance management in iOS. When battery health drops below 80%, your iPhone may throttle processor speed to prevent unexpected shutdowns. This means:
- Slower app launch times
- Lower frame rates in games
- Reduced speaker volume
- Slower background app refresh
A battery replacement restores full performance.
Should You Replace the Battery?
A battery replacement typically costs - in Australia. If you are buying a used iPhone with below 80% battery health, factor this cost into your budget. At USEDIPHONE, we offer Refurbished New battery option on many models - a brand new battery installed before shipping.
Tips to Maintain Battery Health
- Avoid extreme temperatures (below 0C or above 35C)
- Do not always charge to 100% - 80% is ideal for long-term health
- Use certified chargers (all our chargers are certified)
- Update to the latest iOS for battery optimisations
- Enable Optimised Battery Charging in Settings
- Remove thick cases during charging if the phone gets hot
Battery Health at USEDIPHONE
Every used iPhone at USEDIPHONE comes with a clearly labelled battery health rating. You can choose from:
- Below 80% - Budget option
- 85%-95% - Good battery health
- 100% - Maximum capacity
- Refurbished New - Brand new replacement battery
Browse our iPhones and filter by battery health to find your perfect match.