Xiaomi MI Ruby 15.6 Replacement Battery N15B01W 15.4V

Xiaomi MI Ruby 15.6 — 15.4V Li-Polymer Replacement Battery (N15B01W)

This is a Li-Polymer replacement battery for the Xiaomi MI Ruby 15.6 laptop. It carries a 15.4V nominal voltage and 2500mAh (38.5Wh) capacity, matching the original N15B01W specification. It fits the MI Ruby 15.6 directly, restoring untethered use when the original cell has degraded or failed.

• MI Ruby 15.6 fitment: The N15B01W uses a specific connector pinout and BMS handshake matched to the MI Ruby 15.6 motherboard. The voltage rail and protection circuit parameters are set to what the system expects — not a generic 15.4V pack.
• Bench tested on actual hardware: We cycled this cell on the MI Ruby 15.6 platform, confirming BMS communication, charge acceptance, and discharge cutoff at the correct low-voltage threshold. The protection circuit tripped cleanly at full depletion with no over-discharge event recorded.
• First-cycle reset procedure: After installation, run the laptop on battery until it hibernates at cutoff, then charge uninterrupted to 100% without interruption. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears after every cell swap.

Why the MI Ruby 15.6 shuts down at 20–30% remaining after a battery swap

This happens because the BIOS fuel gauge IC still holds calibration data from the old, degraded cell. When the new cell hits what the system thinks is near-empty, it forces an immediate shutdown — even though the cell has capacity left. The voltage under full CPU and display load drops steeply at that state-of-charge point, which the uncalibrated gauge misreads as a critical threshold. Run two full discharge-to-hibernate and uninterrupted charge-to-100% cycles to allow the fuel gauge IC to recalibrate against the new cell's actual voltage curve.

BIOS reporting new N15B01W battery health as poor or unknown immediately after install

The MI Ruby 15.6 BIOS reads health data stored in the battery's EEPROM and compares it against charge history from the previous cell. A fresh cell has no accumulated cycle data, so the system flags it as unknown or degraded — this is a data mismatch, not a fault with the replacement cell. The fix is a full battery learn cycle: discharge fully to hibernate cutoff, then charge to 100% without interruption. After one to two complete cycles, the BIOS rewrites its health reference and the warning clears. If it persists beyond three cycles, check BIOS version — some MI Ruby 15.6 firmware builds require an update to handle cell resets correctly.