About this replacement
Skyroam Gmate Series — 3.7V Li-ion Replacement Battery (BL-4BS)
This is a 3.7V, 700mAh Li-ion replacement battery for the Skyroam Gmate and Gmate Plus mobile hotspot. Part number BL-4BS. It fits directly into both models and restores power to the hotspot when the original cell has degraded or failed.
- Gmate and Gmate Plus compatibility: Both models use the same BL-4BS cell, voltage rail, and connector pinout. The BMS handshake is identical across both variants, so this single cell covers the full Gmate line without modification.
- Bench tested on actual hardware: We ran this cell under combined WiFi broadcast and LTE modem load — the conditions that draw the most current. The BMS held stable voltage throughout and did not trip on the startup surge when the cellular radio initialised.
- Ventilation during extended sessions: Keep the hotspot on a hard, flat surface during long sessions. When connected devices are far from the hotspot, the cellular radio runs at maximum transmit power. That heat accumulates inside the casing and stresses the cell directly — a clear surface lets it dissipate.
Hotspot disconnecting users mid-session on a new battery
The Gmate runs two radios simultaneously — the LTE modem and the WiFi access point. When multiple devices are connected and the cellular signal is weak, both radios operate at peak draw at the same time. This creates a combined current spike that can pull the cell voltage below the BMS cutoff threshold momentarily. The result is a brief power interruption that drops all connected clients. Reducing the number of active devices or moving closer to a cellular tower lowers the combined draw and stabilises the voltage.
Hotspot won't power on after sitting unused for several weeks
Li-ion cells self-discharge during storage. If the Gmate sat unused long enough, the cell voltage can drop below the minimum boot threshold — typically around 3.0V — and the device will show no response when you press the power button. Connect the hotspot to a charger and leave it for at least 30 minutes before attempting to power it on. If the charge LED does not activate, the cell may have dropped below the BMS recovery floor; in that case, disconnect and reconnect the charger to trigger a re-initialisation cycle.