Mifcom EG5 NH55RCQ Replacement Battery 14.4V 2200mAh

Mifcom EG5 i7-GTX 1660 Ti(NH55RCQ) — 14.4V Li-ion Replacement Battery (6-87-NH50S-41C00)

This is a 14.4V Li-ion battery rated at 2200mAh (31.68Wh), built to replace the original cell in the Mifcom EG5 i7-GTX 1660 Ti (NH55RCQ) gaming laptop. It matches OEM part numbers 6-87-NH50S-41C00 and NH50BAT-4. Install this when the original battery no longer holds a charge or the system refuses to run unplugged.

• NH55RCQ platform fit: The NH55RCQ chassis uses a 4-cell Li-ion configuration on a 14.4V rail with a specific BMS handshake tied to part number 6-87-NH50S-41C00. Both OEM part numbers cross-reference the same connector pinout and cell count, so the BMS accepts this unit without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the NH55RCQ platform. The BMS initialised correctly, charge current ramped as expected, and the protection circuit triggered at appropriate low-voltage thresholds without false cutoff.
• Post-swap recalibration on the NH55RCQ: After fitting a new cell, run one full discharge down to the hibernate cutoff, then charge uninterrupted to 100%. The NH55RCQ's BIOS uses this cycle to reset its battery learn cycle — skipping it leaves the fuel gauge IC uncalibrated and the BIOS reporting inaccurate health data.

BIOS reporting poor battery health immediately after fitting a new cell

The NH55RCQ BIOS reads health data from EEPROM registers stored in the original cell's fuel gauge IC. When a replacement cell goes in, those registers are either blank or carry stale data from the old battery. The BIOS interprets this as degraded capacity and flags a health warning. Run one full discharge-to-hibernate then a full uninterrupted charge to 100% — this triggers the battery learn cycle and rewrites the EEPROM health values against the new cell's actual chemistry.

Laptop shuts down with 20–30% charge shown on screen

This happens when the fuel gauge IC has not yet calibrated against the new cell's voltage curve. Under combined CPU and display load on the GTX 1660 Ti platform, current draw spikes sharply and the uncalibrated gauge misreads remaining capacity — the real cell voltage has already hit the low-voltage cliff before the reported percentage reaches zero. It is not a cell fault. Complete two to three full discharge-to-charge cycles without interrupting charge. After calibration, the gauge tracks the voltage curve accurately and shutdowns at low charge should stop.