Redmi Note 10 5G BN5A Compatible Battery 3.85V 4900mAh

Redmi Note 10 5G / Note 10T Series — 3.85V Li-Polymer Replacement Battery (BN5A)

This is a 3.85V, 4900mAh (18.87Wh) Li-Polymer cell built to the BN5A specification. It fits the Redmi Note 10 5G, Note 10T, Note 10T 5G, and the M2103K19G variant. If your original cell has degraded through repeated charge cycles and the phone no longer holds charge through a full day, this swap restores full cell capacity.

• Note 10 5G and Note 10T compatibility: These models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The BN5A cell fits all listed variants without modification — the connector seats and locks the same way across the M2103K19G board revision.
• Bench tested on actual hardware: We cycled this cell on a Note 10 5G board and confirmed the BMS accepted the cell, fast charge negotiation completed on the second cycle, and the fuel gauge IC tracked state-of-charge without erratic jumps after one full calibration cycle.
• Fuel gauge recalibration on first install: On first use after installation, disable fast charging and run one complete discharge down to shutdown, then charge fully to 100%. This gives the coulomb counter one clean reference cycle against the new cell's discharge curve before high-current charging resumes.

Why the Note 10 5G reports wrong battery percentage after a cell swap

The fuel gauge IC on this phone learns cell capacity by tracking coulombs in and out over time. When you swap to a new cell, the IC still holds the discharge curve it mapped to the worn original — so the percentage it displays is based on stale data. The phone may show 40% remaining and shut down, or jump from 60% to 20% under 5G modem load. One full discharge-to-shutdown followed by an uninterrupted charge to 100% resets the coulomb counter's reference points. After that single cycle, percentage readings stabilise.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC is still calibrated to the old, degraded cell and does not account for the new cell's different voltage cliff profile. Under high-draw events — 5G modem handoff, screen at full brightness, or GPS active — the cell voltage dips briefly below the BMS protection threshold even though the reported percentage looks safe. The BMS reads actual cell voltage, not the OS percentage, and cuts power to protect the cell. Force a full discharge until the phone shuts itself off, then charge to 100% uninterrupted. After one complete cycle the fuel gauge recalibrates and the cutoff point drops back to the correct 3.0V floor.