BL-G021A Fly IQ446 Compatible Battery 3.7V 2300mAh

Fly IQ446 / Elegance 2 — 3.7V Li-Polymer Replacement Battery (BL-G021A)

This is a 3.7V, 2300mAh lithium-polymer cell replacing the OEM BL-G021A battery in the Fly IQ446 and Elegance 2 smartphones. It fits the internal bay directly and connects via the original flex connector. Capacity is 8.51Wh — matching the stock specification.

• IQ446 and Elegance 2 compatibility: Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The BL-G021A reference covers both variants — no hardware modification needed.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge passes on an IQ446 unit. The BMS accepted the cell without fault flags, and the charge IC stepped through CC/CV phases normally with no thermal interruption.
• Fuel gauge recalibration on first use: On first use after installation, disable any fast-charge mode and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated state.

Sudden shutdown at 20–30% on the Fly IQ446 after a cell swap

This is a voltage cliff issue, not a capacity fault. A fresh Li-Polymer cell has a steeper voltage drop at lower states of charge than a worn cell. The phone's modem and display draw a combined spike that pushes the cell voltage below the BMS cutoff threshold — typically 3.0V — before the fuel gauge reaches zero. It looks like the battery drained instantly, but the cell simply cannot sustain voltage under that momentary load. One full discharge-charge cycle recalibrates the coulomb counter and shifts the OS shutdown curve to match the new cell's actual voltage profile.

Phone won't power on after the replacement battery sat in storage

Li-Polymer cells self-discharge in storage. If the replacement cell dropped below approximately 2.5V per cell during storage, the BMS enters a lockout state and blocks normal charging to prevent damage. The phone appears completely dead — no boot, no charge indicator. Connect the phone to a low-current USB source (500mA wall adapter, not a fast charger) and leave it for 20–30 minutes. Once the BMS detects sufficient voltage recovery, it re-initialises and normal charging resumes — confirm with a stable charge indicator on screen.