Smrat Pro M028AT Mobile Hotspot Replacement Battery 3.7V 3000mAh

Smrat Pro M028AT — 3.7V Li-ion Replacement Battery (M20H)

This is a 3.7V, 3000mAh (11.1Wh) Li-ion replacement battery for the Smrat Pro M028AT portable WiFi hotspot. It fits directly in place of the original M20H battery. If your hotspot is shutting down under load or no longer holding a charge, this replaces the worn cell.

• M028AT platform fit: The M028AT uses a single-cell 3.7V Li-ion pack with the M20H part number. The BMS on this device monitors cell voltage directly — a mismatched cell voltage or connector pinout will prevent boot. This replacement matches both.
• Bench tested on actual hardware: We ran this battery under simultaneous modem and WiFi radio load. The BMS handled the combined draw without tripping a false low-voltage cutoff, and the cell voltage held stable across the test cycle.
• Signal-strength charging caution: Keep the hotspot near your cellular signal source during heavy use. When signal is weak, the modem boosts transmit power to maintain the connection — this raises heat output directly against the battery. Sustained poor-signal sessions accelerate cell wear faster than normal use.

Why the M028AT cuts connected devices mid-session

When the M028AT is running at maximum connected devices, the modem and WiFi radio draw simultaneously. If the battery cell voltage sags below roughly 3.2V under this combined load, the BMS triggers a protective cutoff — dropping all connected clients instantly. This is not a firmware fault. It happens most often with aged cells that can no longer sustain the peak draw. A fresh cell with rated capacity eliminates the sag that causes the trip.

Hotspot won't power on after sitting unused for weeks

Li-ion cells self-discharge during storage. If the M028AT sits unused long enough, the cell can drop below the minimum boot voltage — typically around 3.0V — and the BMS will block startup to protect the cell. Plugging in the charger for 15–20 minutes before pressing the power button allows the cell to recover to a bootable voltage. If the device still won't power on after a full charge cycle, the original cell has likely degraded past recovery and needs replacement.