If you own a Samsung Galaxy smartphone and want to inspect real-time battery diagnostics without third-party apps, Samsung includes a built-in USSD diagnostic menu.
What is the
Dialing *#0228# opens the hidden BatteryStatus screen in Samsung's One UI / Android firmware. It provides direct, low-level telemetry from the battery management system (BMS).How to Access the Battery Status Menu
- Open the stock Phone (Dialer) app on your Samsung device.
- Dial *#0228# (no need to press the call button; the menu should open automatically).
- The BatteryStatus screen will appear immediately.
Understanding the Key Metrics
- Voltage: Displays live operational voltage in millivolts ($mV$). A standard Lithium-Ion cell runs around $3,700\text{ mV}$ to $4,350\text{ mV}$ depending on the current charge level.
- Level / ADC: Shows the current battery percentage and the raw analog-to-digital converter reading reported by the fuel gauge IC.
- Current Value: Displays real-time current draw or charge rate in milliamps ($mA$). Positive or negative values depend on whether the phone is charging or discharging.
- Average Value: The smoothed moving average of the current draw, useful for identifying abnormal background battery drain.
- Type: Battery chemistry (typically standard Li-ion).
What Does the "Quick Start" Button Do?
At the bottom of the screen, you will notice a red Quick Start button.- Purpose: It forces the fuel gauge IC to recalibrate its state of charge (SoC) estimation by resetting the learned capacity tables and re-reading the open-circuit voltage.
- What happens when pressed: The screen will turn black for a few seconds and lock. Once unlocked, you may see your battery percentage drop or jump (e.g., from 70% to 58%).
- Warning: Use this only if your battery percentage jumps erratically or shuts down unexpectedly at 15–20%. Do not tap it repeatedly during normal daily use, as it temporarily disrupts the fuel gauge's learned discharge curves.
