AT&T Unite W-5 Replacement Battery 3.7V 2000mAh

AT&T Unite / UNITE-344B — 3.7V Li-ion Replacement Battery (W-5)

This 3.7V, 2000mAh Li-ion battery replaces the original W-5 cell in the AT&T Unite and UNITE-344B portable mobile hotspot. It slots directly into the battery bay and communicates with the device's onboard charging circuit. Use the capacity figure from product data — 2000mAh / 7.4Wh — as your baseline for comparing against your original.

• Unite and UNITE-344B compatibility: Both models run the same 3.7V single-cell architecture with an identical connector footprint and BMS handshake protocol. One battery covers both variants without any modification.
• Bench tested on actual hardware: We cycled this cell under simultaneous modem and Wi-Fi radio load — the BMS held the charge curve steady and did not trip the over-current protection during multi-device connection bursts.
• Ventilation during extended hotspot sessions: Keep the Unite on a hard, flat surface with the battery panel unobstructed. When connected devices are far from the hotspot, the cellular radio runs at full output power. That heat buildup sits directly against the battery — poor airflow accelerates cell degradation faster than charge cycles alone.

Why the Unite drops connected devices mid-session under heavy load

The Unite runs two power-hungry systems simultaneously — the cellular modem and the Wi-Fi radio. At maximum connected devices, combined draw spikes sharply. If the battery cell has degraded internal resistance, voltage sags below the threshold the modem needs to maintain its uplink, triggering a momentary shutdown of the radio stack. The Wi-Fi network drops for all connected users even though the device appears to stay on. A fresh cell with lower internal resistance keeps voltage stable through those draw spikes.

Unite shows charging indicator but won't power on after sitting unused

A hotspot stored with a low charge will self-discharge over weeks until the cell voltage drops below the minimum boot threshold — typically around 3.0V for this chemistry. The device may flash the charging LED but refuse to boot because the BMS blocks power delivery until the cell recovers to a safe level. Plug in via the original charger and leave it connected for at least 30 minutes before attempting to power on. If the cell has been sitting at or near 0V for an extended period, it may not recover — replace the battery and confirm the new cell reads above 3.2V before first boot.