Android hides battery health better than iPhones do, but it's readable: some makers show it in settings, dialer codes reveal it on others, and ADB works on everything.
- 1Check settings first: Samsung (Battery → Battery protection/diagnostics), or Settings → About phone → Battery on some brands.
- 2Try the dialer code *#*#4636#*#* → Battery information (works on many models).
- 3Universal ADB route: enable USB debugging, connect to a computer, run 'adb shell dumpsys battery', read charge counter vs. full capacity.
- 4Compare current capacity to the factory mAh with our Battery Health Calculator.
- 5Below 80%? Expect short life and sudden shutdowns, plan a replacement.
Tip: Battery apps that 'measure' health without ADB mostly estimate from charge curves, use them as a hint, not a verdict.