axiom-energy

# Energy Optimization

## Overview

Energy issues manifest as battery drain, hot devices, and poor App Store reviews. **Core principle**: Measure before optimizing. Use Power Profiler to identify the dominant subsystem (CPU/GPU/Network/Location/Display), then apply targeted fixes.

**Key insight**: Developers often don't know where to START auditing. This skill provides systematic diagnosis, not guesswork.

**Requirements**: iOS 26+, Xcode 26+, Power Profiler in Instruments

## Example Prompts

Real questions developers ask that this skill answers:

#### 1. "My app is always at the top of Battery Settings. How do I find what's draining power?"
→ The skill covers Power Profiler workflow to identify dominant subsystem and targeted fixes

#### 2. "Users report my app makes their phone hot. Where do I start debugging?"
→ The skill provides decision tree: CPU vs GPU vs Network diagnosis with specific patterns

#### 3. "I have timers and location updates. Are they causing battery drain?"
→ The skill covers timer tolerance, location accuracy trade-offs, and audit checklists

#### 4. "My app drains battery in the background even when users aren't using it."
→ The skill covers background execution patterns, BGTasks, and EMRCA principles

#### 5. "How do I measure if my optimization actually improved battery life?"
→ The skill demonstrates before/after Power Profiler comparison workflow

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## Red Flags — High Energy Likely

If you see ANY of these, suspect energy inefficiency:

- **Battery Settings**: Your app consistently at top of battery consumers
- **Device temperature**: Phone gets warm during normal app use
- **User reviews**: Mentions of "battery drain", "hot phone", "kills my battery"
- **Xcode Energy Gauge**: Shows sustained high or very high impact
- **Background runtime**: App runs longer than expected when not visible
- **Network activity**: Frequent small requests instead of batched operations
- **Location icon**: Appears in status bar when app shouldn't need