Netgear AirCard 790 Replacement Battery W-7 3.7V 2000mAh

Netgear AirCard 790 / 790s Series — 3.7V Li-ion Replacement Battery (W-7)

This is a 3.7V, 2000mAh Li-ion battery for the Netgear AirCard 790 and 790s mobile hotspot. It replaces OEM part numbers W-7, W-7a, W-7b, W-8a, and 5200087. If your hotspot is shutting down unexpectedly, draining fast, or no longer holding a usable charge, this battery addresses that directly.

• AirCard 790 and 790s fit: Both the 790 and 790s share the same battery bay dimensions and connector pinout. The BMS handshake protocol is identical across this family, so the same cell works across all listed variants without firmware conflicts.
• Bench tested on actual hardware: We ran this battery in an AirCard 790s under a simulated multi-device load — five connected clients with active data transfer. The BMS held voltage above 3.5V throughout discharge and triggered the low-voltage cutoff cleanly without a hard crash.
• Session heat management: Keep the hotspot on a hard, flat surface during long sessions. When the cellular radio is working hard in a weak signal area, it draws maximum transmit power. That heat accumulates in the battery compartment and shortens cell life faster than normal discharge cycles.

Why the AirCard 790 drops all connected devices mid-session

The AirCard 790 runs two radios simultaneously — the LTE modem and the WiFi access point — off a single 3.7V cell. When multiple devices are pulling data at once, the combined current draw can cause a momentary voltage sag below the BMS protection threshold. The BMS reads this as an unsafe condition and cuts output, which the device registers as a hard shutdown rather than a graceful power-off. A degraded original battery accelerates this because its internal resistance is higher, making the sag steeper under the same load. A fresh cell with lower internal resistance holds voltage more steadily through those peak-draw spikes.

AirCard 790 won't power on after sitting unused for weeks

Li-ion cells self-discharge at roughly 2–3% per month at room temperature. If the hotspot sat in a drawer with a partially depleted battery, the cell may have dropped below the BMS re-enable threshold — typically around 2.5V to 2.8V — and the protection circuit has locked the output. Plugging into the charger and leaving it for 30–60 minutes allows the charger to push a trickle current that brings the cell back above the BMS reset point. If the device still shows no charge indicator after that window, the original battery has dropped below recoverable voltage and needs replacing.