WattFlow

See the real watts flowing in and out of your battery — wired or wireless, in real time.

Features

- Live power readout — voltage × current sampled every second, shown in watts - Wired & wireless — detects AC / USB / Wireless / Dock sources automatically - Animated visuals — current dots flowing along the cable when wired, pulsing waves when wireless, outflow animation when discharging - Peak In / Peak Out — tracks maximum charging and discharging power of the session - Live graph — last 60 seconds of power history, discharge shown below the zero line - Battery stats — voltage, current, temperature, and charge level inside the battery icon - 12 languages — auto-follows system, with a manual override in settings - No ads, no analytics — nothing about you ever leaves this device.

How It Works

Power is computed from Android's public BatteryManager API:

watts = EXTRA_VOLTAGE (mV) × BATTERY_PROPERTY_CURRENT_NOW (µA)

The app normalizes two well-known OEM quirks:

- Some devices report current in mA instead of µA (values are scaled by a plausibility heuristic) - Sign conventions differ per vendor (normalized to: charging = positive)

Accuracy Disclaimer

The displayed value is battery-side power — what actually enters or leaves the battery cell. Wall power is always higher due to:

- Conversion losses (~10–15% wired, ~30–40% wireless) - Power consumed directly by the device (screen, CPU, radios) while charging

There is no public Android API for adapter-side wattage, so this is the most honest number an unrooted device can show.

Reverse Charging

When your phone powers another device (reverse wireless charging, OTG), Android exposes no "reverse charging" flag — the app shows it as battery drain with the correct wattage.

Languages

English, 简体中文, 繁體中文, Español, العربية, Bahasa Indonesia, Português, Français, 日本語, 한국어, Русский, Deutsch

License

MIT