**Battery Action Plan** - Home now opens with a ranked coach that turns heat, charge band, runtime, drain, and charging-session history into next steps. **Battery Field Guide** - Settings now includes a bundled offline guide with 22 visual reference plates covering heat, charging, travel runtime, low-power planning, cable checks, and iOS API limits. **Evidence links** - The new action card links directly to Apple battery guidance and public UIDevice API documentation so the recommendations stay transparent. **Clear severity tags** - Actions are labeled Now, Important, Watch, or Info so the next step is obvious at a glance. **More test coverage** - Added unit tests for hot charging, high charge dwell, empty-history behavior, and calm-history maintenance guidance.

This update sharpens the interface: the iPad layout now uses a centered, comfortable reading width instead of stretching edge to edge, so every screen reads as a clean column. iPhone is unchanged; still fully on-device.

CellArc 2.0 — a pro upgrade that turns your battery time-series into longevity intelligence, still 100% offline. • Live Forecast: real-time time-to-full and time-to-empty from your recent rate, with a slow-top-off caveat above 80%. • Charge Coach: percent of time in the 20–80% sweet spot, daily "kept under 80%" streaks, and a per-charge stress curve. • Drain Rhythm: drain rate by hour of day, your worst hours, and a screen-on vs idle split. • Charge Analyzer: a charging-discipline score (speed, overnight, deep-start, overcharge frequency). • Heat Exposure: an Arrhenius-weighted heat-stress score and a hot-while-charging warning. • An opt-in charge-limit reminder and a one-page PDF battery report. Honest by design: iOS doesn't expose true capacity, so figures are clearly estimates. No account, no network — everything stays on your device.

What's New in CellArc 1.1 (Build 4) Charge Speed Trend — The Charging tab now shows a chart of how long each session took to reach 80%, plotted over your last 40 qualifying sessions with a regression line and a verdict label (Slowing / Stable / Improving). A rising trend is an early signal of capacity loss as the cell's constant-current acceptance rate falls — something no other reading in the app can surface. Model-calibrated Trip Planner — Trip Planner now uses your selected iPhone model's actual watt-hour capacity for all energy math instead of a generic baseline. An iPhone 16 Pro Max trip budget is now correctly larger than an iPhone 12 mini one. Charger Guide — A new offline reference tab with every Apple charger from the 5W legacy cube through MagSafe and 27W USB-C PD: real wattage, speed-to-50% figures, compatibility by model, USB Power Delivery tier explanations, and best-practice guidance. Fully offline, no account.

CellArc 1.1 adds an iPhone Model Library (iPhone 11–17) that calibrates all energy math to your device's actual watt-hour capacity, shows your Apple-rated cycle count alongside CellArc's estimate, exports sessions/rollups/health report as CSV or text, optional smart battery alerts, and a 30-day longevity history sparkline. Fully offline — no account, no tracking.