BatteryRecorder is an Android application for precise battery power recording and battery life prediction. It consists of a main app module with Jetpack Compose UI and a native server daemon that reads battery data directly from sysfs and dumpsys via JNI. The architecture follows a multi-module structure (app, server, shared) with AIDL-based IPC between the app and the privileged background server. The app provides real-time monitoring, historical charts, per-app and per-scenario battery endurance predictions, calibration settings, and export/import capabilities. It is a sophisticated tool aimed at power users and developers, but it relies on device-specific sysfs paths and hidden Android APIs, making it fragile across different devices and Android versions. The codebase demonstrates solid use of modern Android patterns (ViewModel, StateFlow, UseCase, Repository) and custom Compose components, though it lacks automated tests and has mixed-language documentation.