How to Test iPhone Battery Health (2026 Guide)
iPhone battery slower? Phone shutting down at 50%? Here's how to properly test battery health using built-in tools and free apps. Plus when the numbers say 'replace' vs 'wait'.
⚡ Battery Health Tools
These extend your current battery's life, or replace if needed.
Don't damage battery with cheap cables
Cost Breakdown — All Options
| Where | Cost | Wait | Notes |
|---|---|---|---|
| Settings → Battery → Battery Health | Free | Built-in | Most reliable; Apple's official numbers |
| Coconut Battery (Mac app) | Free | Mac required | Detailed cycle count + design capacity |
| 3uTools (Windows/Mac) | Free | Detailed but desktop | Includes wear-level percentage |
| Battery Life app (App Store) | Free | On-device | Quick check; less detailed than built-in |
| Apple Service Diagnostic | Free | At Apple Genius Bar | Authoritative — Apple does the test |
Built-in: Settings → Battery
The fastest, most reliable check:
- Settings → Battery → Battery Health & Charging
- Three numbers matter:
- Maximum Capacity — % of original capacity remaining
- Cycle Count — how many full charge cycles (iPhone 15+ shows this)
- Peak Performance Capability — 'Normal' or 'Service Recommended'
Apple's threshold for replacement under AppleCare+: Maximum Capacity below 80%.
Coconut Battery (Mac) — More Detail
Free Mac app for deeper diagnostics:
- Download Coconut Battery from coconutidentity.de (free)
- Connect iPhone to Mac via cable
- Coconut Battery shows: original design capacity, current full-charge capacity, cycle count, age
- Compare current capacity to design capacity — that's your true battery health %
Useful when Apple's built-in number seems suspicious (e.g., shows 95% but phone dies fast).
3uTools (Windows + Mac) — Most Detailed
Free desktop app, more detailed than Apple's built-in. Shows: battery cycle count, design vs current capacity, wear percentage, manufacture date, charging history. Available at 3u.com.
When to Replace the Battery
Replace if any of:
- Maximum Capacity below 80%
- Cycle Count above 1,000 (iPhone 15+ rated for this) or 500 (iPhone 14 and older)
- 'Service Recommended' message in Battery Health
- Phone shuts down at 30%+ regularly
- Charges to 100% but drains to 50% within 1 hour of light use
Don't replace if just battery percentage looks 'low' — modern iOS is conservative about reporting and a 90% battery is fine for daily use.
Quick Battery Restoration Tips (Before Replacing)
- Update iOS — sometimes iOS includes battery management improvements
- Calibrate the battery — drain to 0%, charge to 100% uninterrupted
- Turn off Background App Refresh for apps you don't use
- Disable Always-On Display (iPhone 14 Pro+)
- Check for runaway apps in Settings → Battery → 24h app usage
These can give you 20–30% more apparent battery life on a degraded battery.
Mail-In Repair Service
Don't have time to wait for Apple? We offer mail-in repair with overnight return shipping.