Xiaomi Mi 13 BP4G Compatible Battery 3.88V 4300mAh

Xiaomi Mi 13 / Mi 13 5G — 3.88V Li-Polymer Replacement Battery (BP4G)

The BP4G is a 3.88V, 4300mAh (16.68Wh) Li-Polymer cell that slots directly into the Xiaomi Mi 13 and Mi 13 5G. It covers both regional variants — model numbers 2211133C and 2211133G. This replacement targets phones where the original cell has degraded and can no longer hold adequate charge under daily load.

• Mi 13 and Mi 13 5G compatibility: Both the standard Mi 13 and its 5G counterpart share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The 78.00 × 61.00 × 5.40mm cell footprint is identical across 2211133C and 2211133G boards, so one part number covers all four variants.
• Bench tested on actual hardware: We ran this cell on Mi 13 hardware and confirmed BMS handshake, charge termination at 4.40V, and correct fuel gauge IC recognition. The protection circuit tripped correctly on simulated short-circuit and over-discharge conditions.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one complete discharge-to-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before Xiaomi's high-current fast charging protocol pushes current into an uncalibrated cell — preventing erratic percentage readings early on.

Sudden shutdown at 20–30% on the Mi 13 after a cell swap

This is a voltage cliff issue, not a capacity issue. A new cell with an uncalibrated fuel gauge IC can show 25% remaining while the actual cell voltage has already dropped below what the Snapdragon 8 Gen 2 and 5G modem demand under peak load. The phone's PMIC interprets this as an emergency low-voltage condition and cuts power to protect the board. One full discharge cycle — letting the phone run down to automatic shutdown, then charging uninterrupted to 100% — resets the coulomb counter against the new cell's real curve. After that cycle, the reported percentage tracks actual cell voltage correctly.

USB-PD or Xiaomi HyperCharge not activating on first cycle after replacement

On the first charge after a cell swap, the charge IC on the Mi 13 may default to standard 5V/0.9A input rather than negotiating fast-charge protocols. This happens because the BMS flags an unrecognised cell state and holds the charge IC in a conservative mode until it completes one baseline charge cycle. The fix is straightforward: charge the phone fully at whatever rate the charger delivers on that first cycle without interrupting it. On the second charge, HyperCharge or USB-PD negotiation resumes normally — confirm by checking that the charger brick warms up within the first two minutes of connection.