Netgear Aircard 782s Replacement Battery W-5 3.7V 2000mAh

Netgear Aircard 782s / Unite AC770S — 3.7V Li-ion Replacement Battery (W-5)

This is a 3.7V, 2000mAh Li-ion battery with OEM part number W-5, replacing the original power cell in the Netgear Aircard 782s, Unite AC770S, and UNITE-344B mobile hotspots. These devices broadcast a wireless signal to multiple clients while simultaneously running a cellular modem — a combined load that taxes the battery harder than a typical single-function device. Dimensions are 77.20 x 54.00 x 6.20mm for a direct physical fit.

• Aircard 782s, Unite AC770S, and UNITE-344B compatibility: All three models share the same W-5 battery form factor, voltage rail, and connector pinout. The BMS handshake protocol is identical across the group, so one cell covers all three without firmware or calibration differences.
• Bench tested on actual hardware: We ran this cell under simultaneous cellular modem and multi-client WiFi load. The BMS held a stable discharge curve without triggering thermal cutoff or low-voltage protection trips during sustained sessions.
• Ventilation during extended hotspot sessions: When connected devices are far from the hotspot, the cellular radio pushes to maximum output power. Keep the unit flat on an open surface — not in a bag or pocket — during long sessions to prevent heat buildup that degrades cell capacity over time.

Why the Aircard 782s drops all connected clients mid-session on a new battery

The Aircard 782s runs two high-draw systems at once: the cellular modem and the WiFi radio. When client count hits the device maximum and the cellular signal is weak, instantaneous current draw spikes sharply. If the battery's internal resistance is elevated — either from age or a partially degraded new cell — voltage sags below the BMS protection floor, and the unit cuts power to recover. This appears as a full disconnection rather than a slow fade. Charge the replacement cell fully before the first heavy-load session so the BMS has an accurate state-of-charge baseline to work from.

Aircard 782s won't power on after sitting unused for several weeks

Li-ion cells self-discharge at roughly 2–3% per month under normal storage conditions, but a hotspot left in standby with WiFi broadcasting can drain the pack to near-zero within days. Once cell voltage drops below approximately 2.5V, the BMS enters deep-discharge lockout and the device will not respond to the power button. Connect the unit to the original Netgear charger and leave it for at least 15–20 minutes before pressing power — most BMS circuits require a trickle charge recovery period before they release the lockout and allow a normal boot.