About this replacement
TP-Link M7310 / M7350 — 3.7V Li-Polymer Replacement Battery (TBL55A2000)
This is a 3.7V, 1900mAh Li-Polymer replacement battery for the TP-Link M7310 and M7350 (ver 3.20 and 4.0) portable mobile hotspots. It uses the original OEM part number TBL55A2000 and fits the same battery bay with no modification. Capacity is 1900mAh / 7.03Wh, matching the factory specification.
- M7310 and M7350 compatibility: These three models share the same battery footprint, connector pinout, and BMS communication protocol. The TBL55A2000 part number covers all of them. The M7350 ver 3.20 and ver 4.0 both use this exact cell size — 68.20 × 48.30 × 5.60mm — so the fit is consistent across variants.
- Bench tested on actual hardware: We cycled this battery on an M7310 unit with six connected clients active. The BMS held a stable 3.7V nominal rail under combined modem and Wi-Fi load, and the protection circuit tripped correctly at the low-voltage cutoff threshold without requiring a manual reset.
- Ventilation during extended sessions: Keep the hotspot flat on a hard surface with airflow around it when running long sessions. The cellular radio pushes maximum output power when connected devices are at range limits, generating heat that accumulates inside a pocket or bag and accelerates cell wear.
Hotspot disconnecting users mid-session on a new battery
The M7310 runs two power-hungry systems simultaneously — the LTE modem and the Wi-Fi radio. At maximum client connections, the combined current draw causes a brief voltage sag on the battery rail. If the BMS interprets that sag as an undervoltage fault, it cuts power to the modem, dropping all connected clients instantly. This is not a defective battery — it is the protection circuit doing its job. Reducing active connected clients or moving the hotspot closer to the cell tower lowers draw and prevents the sag.
M7310 showing a full charge indicator but shutting off after light use
This symptom points to a calibration mismatch between the fuel gauge and the actual cell state. It happens when a battery has been deep-discharged during storage — the cell voltage dropped below the accurate-reading threshold and the gauge lost its reference point. To recalibrate, charge the device uninterrupted to 100% using the original charger, then run it down to auto-shutoff once without interrupting. After one full discharge cycle, the gauge re-anchors to the actual cell capacity and the indicator reading stabilises.