Nubia MF673 Compatible Battery 3.8V 2200mAh Li-ion

Nubia MF673 — 3.8V Li-ion Replacement Battery

This 3.8V, 2200mAh Li-ion battery replaces the original cell in the Nubia MF673 portable Wi-Fi hotspot. The MF673 shares cellular data with multiple connected clients over Wi-Fi, and the battery powers both the LTE modem and the wireless radio simultaneously. Capacity is taken directly from product specifications at 8.36Wh.

• MF673 platform fit: The MF673 uses a single-cell 3.8V pack with a specific footprint of 60.50 × 42.36 × 8.20mm. The BMS on this unit monitors cell voltage and temperature — any replacement must match cell voltage exactly or the firmware refuses to charge.
• Bench tested on actual hardware: We ran this cell under combined modem and Wi-Fi radio load, simulating four connected clients. The BMS held charge acceptance cleanly and did not trip on the startup current spike from the cellular modem initialising.
• Ventilation during extended sessions: Keep the MF673 on a hard, flat surface with clear airflow on all sides during long sessions. When connected clients are far from the unit, the cellular radio runs at maximum transmit power — that extra heat feeds directly into the battery cell and accelerates wear over time.

Why the MF673 drops connected clients mid-session

When several devices are active at once, the modem and Wi-Fi radio draw current simultaneously. If the cell has degraded internal resistance, voltage sags below the BMS protection threshold briefly — the firmware reads this as a fault and resets the radio stack. That reset looks like a Wi-Fi drop to every connected client. A fresh cell with low internal resistance holds voltage stable through those combined-load spikes and keeps the radio running without interruption.

MF673 won't power on after sitting unused

Li-ion cells self-discharge during storage. If the MF673 sat unused for several weeks, the cell may have dropped below the minimum boot voltage — typically around 3.0V for this cell chemistry — and the BMS locks out the discharge path entirely to protect the cell. Connect the hotspot directly to a wall charger, not a low-output USB port, and leave it for at least 30 minutes before attempting to power on. If the charge LED does not light within five minutes, the original cell has gone below recovery voltage and replacement is the correct next step.