{"product_id":"sprint-aircard-771s-replacement-battery-37v-2000mah-li-ion","title":"Sprint AirCard 771S Replacement Battery 3.7V 2000mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSprint AirCard 771S \/ 770S — 3.7V Li-ion Replacement Battery (W-5)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 2000mAh Li-ion battery for the Sprint AirCard 771S and AirCard 770S mobile hotspots. Both units share the same battery bay, connector, and BMS handshake protocol. It slots in directly and the hotspot powers on without reconfiguration.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eAirCard 771S and 770S compatibility:\u003c\/strong\u003e\n    Both models run the same 3.7V power rail with an identical physical footprint and BMS communication line. The same cell works across both units — no firmware difference affects battery recognition.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell under combined cellular modem and Wi-Fi radio load — the BMS held steady through the high-draw startup sequence and maintained voltage without false low-battery cutoffs.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eVentilation during extended sessions:\u003c\/strong\u003e\n    Keep the hotspot flat on a hard surface with the vents unobstructed. When connected devices are far away, the cellular radio runs at full output power. That heat builds up fast in a pocket or bag and accelerates cell degradation.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eHotspot disconnecting users mid-session on a new battery\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen multiple devices connect simultaneously, the modem and Wi-Fi radio draw current at the same time. This combined load can pull the cell voltage down briefly — even on a new battery — triggering the BMS undervoltage cutoff. The hotspot reboots, and all connected sessions drop. Reducing the number of active connected devices or moving the hotspot closer to the cell tower lowers instantaneous draw and stops the dropout cycle.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eAirCard 771S won't power on after sitting in a drawer\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge over storage time. If the voltage drops below roughly 3.0V, the BMS locks out normal charging to protect the cell. The hotspot shows nothing — no charging LED, no boot screen. Plug it in and leave it on the charger for 30–45 minutes without pressing the power button. The charger applies a trickle current that brings the cell back above the 3.0V BMS re-enable threshold, after which normal charging resumes.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43377858543706,"sku":"BWCS-SPT771RC-1","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43377858576474,"sku":"BWCS-SPT771RC-2","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43377858609242,"sku":"BWCS-SPT771RC-3","price":31.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SPT771RC-1.webp?v=1778773940","url":"https:\/\/batteryweb.com\/products\/sprint-aircard-771s-replacement-battery-37v-2000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}