Energy Optimization

Power Profiler workflows for identifying and fixing battery drain. Covers CPU, GPU, Network, Location, and Display subsystem diagnosis with anti-pattern fixes.

When to Use This Skill

Use this skill when you're:

• App appears at top of Battery Settings
• Device gets hot during normal use
• Users report battery drain in reviews
• Xcode Energy Gauge shows sustained high impact
• Background runtime exceeds expectations
• Preparing for App Store release

Core principle: Measure before optimizing. Use Power Profiler to identify which subsystem dominates, then apply targeted fixes.

For symptoms: See energy-diag for decision trees with time-cost analysis.

For API reference: See energy-ref for complete code examples from WWDC.

Example Prompts

Questions you can ask Claude that will draw from this skill:

• "My app is draining battery faster than expected."
• "Device gets hot when using my app."
• "How do I use Power Profiler to find energy issues?"
• "My app uses too much energy in the background."
• "What's causing high CPU usage?"

What's Covered

Power Profiler Workflow

• Running baseline measurement (5 min)
• Identifying dominant subsystem
• Before/after verification

CPU Subsystem

• Timer leaks and polling loops
• Eager loading vs lazy loading
• Background task duration
• Repeated parsing

GPU Subsystem

• Animation visibility (hidden views still animate)
• Blur effects over dynamic content
• Complex compositing (shadows, masks)
• Frame rate optimization

Network Subsystem

• Polling vs push notifications
• Request batching
• Discretionary flag for background
• Connection coalescing

Location Subsystem

• Continuous updates vs significant-change
• Accuracy requirements
• Background location modes
• Deferred location updates

Display Subsystem

• Dark mode for OLED battery savings
• Reduce brightness API usage
• EDR (Extended Dynamic Range) impact

Key Pattern

Energy Decision Tree

Quick Power Profiler Workflow

# 1. Open Instruments
open -a Instruments

# 2. Select "Power Profiler" template
# 3. Record for 2-3 minutes of typical app usage
# 4. Identify which lane (CPU/GPU/Network/Location/Display) is high
# 5. Apply fixes for that subsystem
# 6. Record again to verify improvement

Documentation Scope

This page documents the axiom-energy skill—Power Profiler workflows Claude uses when you're diagnosing battery drain in your iOS app.

For symptom-based diagnosis: See energy-diag for decision trees starting from symptoms like "phone gets hot".

For complete API reference: See energy-ref for code examples and WWDC patterns.

Related

• energy-diag — Symptom-based energy troubleshooting
• energy-ref — Complete API reference with WWDC examples

Resources

WWDC: 2025-226, 2025-227, 2022-10083

Docs: /xcode/improving-your-app-s-performance