Battery & Power
PERFORMANCE › Runtime
How Doze, standby buckets, and WorkManager constraints govern deferred background work to save battery.
Battery and power management is a staple of senior Android interviews because it separates engineers who fire-and-forget background work from those who design for the OS's aggressive power-saving model. Interviewers probe whether you understand how Doze and App Standby Buckets defer jobs, alarms, and network access, and how to schedule work correctly with WorkManager and constraints. Expect questions on exemptions, FCM priority, and how to diagnose battery drain with tools like Battery Historian and adb.
What this covers
- Doze mode mechanics: stationary/unplugged/screen-off triggers, deferred work, and shrinking maintenance windows
- App Standby Buckets (Active, Working set, Frequent, Rare, Restricted, Never) and the quotas each imposes
- Scheduling deferrable work with WorkManager and its Constraints (network, charging, idle, battery-not-low)
- Surviving Doze for time-critical work: setAndAllowWhileIdle, FCM high-priority, foreground services, exemptions
- Battery Saver, background execution limits, and why polling and wake locks drain battery
- Diagnosing drain with Battery Historian, JobScheduler/AlarmManager batching, and adb deviceidle commands
Study this topic
- Battery & Power explained: the guided lesson
- 14 practice quiz questions
- 9 revision flashcards
- Battery & Power interview questions and answers