Know your battery's real health.
Power Battery shows what Android keeps hidden: an estimate of your battery's health and capacity, charge cycles and live charging speed in watts — plus Volt, an AI advisor (beta) that explains your data in plain language. Honest monitoring: no fake “boosting”, no killing apps.
▶ Get it on Google Play
What Power Battery shows you
- Battery health estimateEstimated full-charge capacity (mAh) against the design capacity your phone declares. If your phone declares none, the app shows “—” instead of guessing.
- Charging speed in wattsLive current (mA) and power (W) while charging or discharging, plus a charger speed test.
- Charge cyclesRead directly from the phone on Android 14+ where it is reported; otherwise estimated from your history and labelled as an estimate.
- Wear predictionAn estimate of the days until a replacement is worth considering, with your wear trend over time.
- Ask Volt (beta)Plain-language AI answers built from your own battery data. AI can be imprecise, so every answer carries a notice.
- ProCare insights, the charge-limit alarm, history & graphs, the weekly AI report, unlimited Volt chats, themes and CSV/JSON export.
Battery health questions, answered
How do I check battery health on Android?
Most Android phones have no battery health screen, and Android gives apps no public “state of health” value. Power Battery estimates it instead: it watches your phone's charge counter as the battery level changes to estimate the full-charge capacity in mAh, then compares that with the design capacity your phone declares. The result is an estimate and is labelled as one; on phones that declare no design capacity, the app shows “—” rather than a made-up percentage. A few recent phones also show battery health in their own Settings.
What do mAh and design capacity mean?
mAh (milliamp-hours) measures how much charge a battery holds. Design capacity is what the battery held when new — for example 5,000 mAh. As lithium-ion cells age they hold less, so a battery that now holds about 4,300 mAh is at roughly 86% health. Health is about the size of the “tank”, not the charge percentage in your status bar.
Why doesn't Android show battery health, and what does Power Battery do instead?
Android exposes a charge counter, current, voltage, temperature and, on Android 14+, a cycle count on many phones — but no public battery-health value, and the system battery files are closed to apps. Power Battery works only with what Android allows: it derives capacity from the change in the charge counter across a change in battery level, and uses the design capacity your phone reports. It never claims more precision than the phone provides.
How can I see my battery's charge cycles?
On Android 14 and later, many phones report their charge-cycle count; Power Battery reads it directly and marks it as reported by your device. On older phones, or phones that don't report it, the app estimates cycles from your charging history and labels the number as an estimate. One cycle is 100% of charge in total — two charges from 50% to 100% make one cycle.
Is Power Battery safe, and what data is sent to the AI?
Battery readings are stored on your phone. Only when you ask Volt a question, or turn on the weekly AI report (Pro), is a summary of your battery numbers — no contacts, accounts or personal identifiers — sent with your question to Google's Gemini API to write the answer. It is not sold. Volt is in beta and can be imprecise, so each answer carries a notice and a one-tap report option. The app asks for Bluetooth (to read connected devices' battery level) and notifications (for alarms and alerts), and never force-closes other apps.
Is Power Battery free?
Yes. The core app is free on Google Play: live battery stats, the health and capacity estimate, charge cycles, charging speed in watts, the speed test, wear prediction, connected-device battery levels, widgets and a limited number of Volt chats. An optional Pro subscription adds unlimited Volt chats, care insights, the charge-limit alarm, history & graphs, the weekly AI report, Light/Dark/Material You themes, CSV/JSON export and priority support.
All battery health questions, answered → · Battery health guide · Charger speed test