Battery Health: Capacity Check

Battery Health is a battery capacity tester and battery monitor: it works out how much real capacity your battery still holds, in mAh, by measuring the charge that actually flows in and out while you charge and discharge. Android has no health number worth trusting, so the app watches the charge counter while the level moves and turns it into an estimate in mAh — shown with the uncertainty range it deserves, not a made-up precision. Battery Health is free with ads. Pro (a subscription or a one-time purchase) removes ads and adds the 30-day summary, charger comparison, the PDF certificate and longer session history; you can try Pro for 30 minutes by watching a short video (ads stay on during the trial). Measurements, alarms, the capacity estimate and CSV export stay free. WHAT YOU GET • Estimated capacity with a ± range, next to the design capacity when the phone reports one • Percent of design capacity, and how many sessions it is built from • Charge cycles, when the phone reports them • Live readings — current in mA, power in watts, voltage, temperature, chemistry • Time estimates — roughly how long until full, or how long is left • Session history — every charge and discharge with level range, duration, current and its own capacity estimate • Session detail — power or current and temperature against level, minutes per 10%, where charging slowed down • Charger & cable test — 60 seconds, the watts this phone gets now, next to your best result on this phone • Cross-check — type the health number your phone shows and see if it agrees with the estimate • Steps for your phone brand when it keeps pausing the app • Quick Settings tile and the level number in the status bar • Graphs of level, temperature or current over 24 hours, 3 days or 7 days — drawn only where samples exist • A wear rating in plain words (Excellent to Heavily worn), flagged when the estimate sits between two ratings • A reason for every session that produced no number, and one clear next step • Charge alarm — set a level (80% is kind to a lithium battery) and the phone beeps once when it gets there • Heat warning at the temperature you choose (35 to 50 °C), or off • Share a health report as text, and CSV export of every sample and session HOW THE ESTIMATE WORKS Charge or discharge about 10% in one go and the first estimate appears; each session refines it. Sampling runs quietly every 15 minutes and when you plug or unplug. The number moves a little between sessions (temperature, charging speed, the phone's own counters), which is why the ± range is there: it is an estimate, not a lab measurement. A result far outside the plausible range for your battery is held back. One uninterrupted charge and one discharge give a first number; a slow overnight charge gives the steadiest. AN HONEST NOTE This app measures and records. It cannot repair a worn battery, and no app can — be wary of anything that claims otherwise. A good measurement helps you decide whether a replacement is worth it. ADS AND PRO, PLAINLY • A banner at the bottom of the main screen, and at most every few minutes a full-screen ad when you leave the session history. Never when the app opens. • Pro: monthly, 3-month or yearly (free trial for new subscribers), or pay once for lifetime. Prices shown before you buy; cancel any time in Google Play. • Had the app before 1.5.0? You keep Pro free. PRIVACY Your battery readings never leave this phone, and there is no account; one button in Settings deletes them all. The app does not read your IMEI or serial number and does not ask for location. Ads (Google AdMob, Unity Ads) may use your advertising ID; where the law requires it, you are asked for consent first. Anonymous usage stats and crash reports (Firebase) can be switched off in Settings and never include your readings. Android 7.0 and up. Every measurement works offline; the internet is used only for ads, purchases and the optional anonymous reporting.