{"product_id":"att-ifwa-40-replacement-battery-37v-3000mah-li-ion","title":"AT\u0026T IFWA-40 Compatible Battery 3.7V 3000mAh BAT-40","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAT\u0026amp;T IFWA-40 — 3.7V Li-ion Replacement Battery (BAT-40)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V 3000mAh Li-ion battery replaces the BAT-40 in the AT\u0026amp;T IFWA-40 Wireless Internet Wi-Fi Hotspot Router and Home Phone Base 4G LTE. It slots directly into the hotspot and restores standalone operation — no wall outlet needed. Capacity is 3000mAh (11.1Wh), matching the original specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eIFWA-40 platform fit:\u003c\/strong\u003e\n    The IFWA-40 runs a combined 4G LTE modem and dual-radio Wi-Fi stack off a single 3.7V cell. The BAT-40 footprint, connector, and BMS handshake match exactly — the device firmware recognises the cell and reports charge level correctly without any workaround.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell under simultaneous modem and Wi-Fi load with multiple client devices connected. The BMS held the discharge curve steady and did not trigger a low-voltage cutoff during sustained throughput sessions.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eCellular signal and battery load:\u003c\/strong\u003e\n    In areas with weak 4G signal, the modem boosts transmit power automatically — this draws significantly more current than normal. Position the IFWA-40 near a window or elevated surface to reduce transmit power demand and reduce heat buildup on the cell.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the IFWA-40 drops connected devices mid-session on a new battery\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe IFWA-40 runs its 4G modem and Wi-Fi radio simultaneously, and peak current draw spikes sharply when multiple clients are active at once. If the battery cell has high internal resistance — even when new — voltage can sag below the BMS cutoff threshold during those spikes, triggering a momentary shutdown. A genuine Li-ion cell with low internal resistance stays above the cutoff under combined load. Check that the battery contacts are clean and seated fully — a loose connection adds resistance and makes voltage sag worse.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eIFWA-40 shows solid red light and won't power on after sitting unused\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA solid red or no-boot condition after storage almost always means the cell dropped below the minimum boot voltage — typically under 3.0V for a 3.7V nominal Li-ion cell. Most Li-ion chargers will not begin a charge cycle on a cell this depleted and simply show no activity. Connect the hotspot to the OEM charger and leave it for 20–30 minutes without attempting to power it on — the charger needs time to trickle-charge the cell back above 3.0V before normal charging begins. If the device still shows no response after 45 minutes on charge, check the charger output voltage with a multimeter — it should read between 4.2V and 5.2V at the connector.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43377812996186,"sku":"BWCS-AFW400SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43377813028954,"sku":"BWCS-AFW400SL-2","price":29.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43377813061722,"sku":"BWCS-AFW400SL-3","price":32.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-AFW400SL-1.webp?v=1778772243","url":"https:\/\/batteryweb.com\/products\/att-ifwa-40-replacement-battery-37v-3000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}