Xiaomi Redmi 10X Pro BM4T Replacement Battery 3.85V 4500mAh

Xiaomi Redmi 10X Pro Series — 3.85V Li-Polymer Replacement Battery (BM4T)

The BM4T is a 3.85V, 4500mAh Li-Polymer cell for the Xiaomi Redmi 10X Pro, 10X Pro 5G, and M2004J7BC. It replaces a degraded original when the phone no longer holds charge or shuts down unexpectedly. Capacity is 4500mAh (17.33Wh), matching the OEM specification.

• Redmi 10X Pro and 10X Pro 5G compatibility: Both variants use the same BM4T footprint, connector pinout, and BMS handshake protocol. The 5G modem draws higher peak current, so the cell must pass the same high-drain BMS negotiation as the LTE version — this unit does.
• Bench tested on actual hardware: We ran charge and discharge cycles on a Redmi 10X Pro unit. The BMS accepted the cell on first connection, charge IC entered CC/CV mode normally, and the coulomb counter began tracking without error flags.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.

Sudden shutdown at 20–30% on the Redmi 10X Pro after a cell swap

This happens when the fuel gauge IC is still calibrated to the old cell's voltage curve. The new cell reaches a voltage cliff — where voltage drops steeply under modem or display load — at a different state of charge than the IC expects. The phone interprets a voltage dip below ~3.5V as imminent shutdown and cuts power, even though percentage still shows 20–30%. One full discharge to 0% followed by an uninterrupted charge to 100% resets the coulomb counter and resolves this.

USB-PD or Xiaomi fast charge not activating on the first cycle after replacement

On a fresh cell, the BMS may not complete the handshake required for fast charge protocols on the first cycle. The charge IC defaults to standard 5V input until it receives a valid BMS response confirming cell state. This is normal behaviour — not a fault with the battery or the charger. Complete one full standard-rate charge cycle first, then fast charging activates on subsequent sessions.