{"product_id":"att-aircard-779s-replacement-battery-37v-2400mah-li-ion","title":"AT\u0026T AirCard 779S Replacement Battery 3.7V 2400mAh W-8","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAT\u0026amp;T AirCard 779S — 3.7V Li-ion Replacement Battery (W-8)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 2400mAh Li-ion battery that replaces part number W-8, 308-10004-01, and W-7b in the AT\u0026amp;T AirCard 779S mobile hotspot. It fits the AirCard 779S, AirCard 779S 4G, AC779S, and NTGR779ABB. When the original cell degrades, connection stability drops before the runtime does — this swap restores full power delivery.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eAirCard 779S platform fit:\u003c\/strong\u003e\n    These model variants share the same battery bay dimensions, W-8 connector pinout, and BMS communication protocol. One battery covers the whole lineup without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell under simultaneous cellular modem and multi-client WiFi load. The BMS held voltage above the hotspot's minimum operating threshold through full discharge cycles without triggering a spurious shutdown.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eCellular session care:\u003c\/strong\u003e\n    Keep the hotspot in an open, ventilated spot during long sessions. When connected devices are far from the hotspot, the cellular radio ramps to maximum transmit power — that sustained output raises internal temperature and accelerates cell wear.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the AirCard 779S drops connections mid-session under full client load\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe 779S runs a cellular modem and a WiFi radio simultaneously. At maximum connected clients, combined current draw can spike beyond what a degraded cell can sustain without voltage sagging. The BMS detects the sag and cuts output to protect the cell — users see a sudden disconnection rather than a warning. A fresh cell with full capacity handles the combined draw without the voltage floor being tripped.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eHotspot shows a charge indicator but won't boot after sitting unused\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge over storage. If the AirCard 779S sits unused for several weeks, the battery can drop below the minimum boot voltage — typically around 3.0V — even though the charge LED may still flicker. The device needs sustained current from a charger, not a single press of the power button. Connect to a known-good USB-C source and leave it for 20–30 minutes before attempting to power on.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43377839767642,"sku":"BWCS-ATP779RX-1","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43377839800410,"sku":"BWCS-ATP779RX-2","price":35.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43377839833178,"sku":"BWCS-ATP779RX-3","price":39.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ATP779RX-1.webp?v=1778773879","url":"https:\/\/batteryweb.com\/products\/att-aircard-779s-replacement-battery-37v-2400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}