{"product_id":"avaya-dect-3749-replacement-battery-37v-1100mah-li-ion","title":"Avaya DECT 3749 Compatible Battery 3.7V 1100mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAvaya DECT 3749 \/ DT413 \/ DT423 — 3.7V Li-ion Replacement Battery (660274\/1B)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1100mAh Li-ion replacement battery for the Avaya DECT 3749, DT413, and DT423 cordless handsets. It replaces OEM part numbers 660274\/1B, 5030472, and 700500842. The cell dimensions match the original pack, so it fits the battery compartment without modification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eDECT 3749, DT413, and DT423 fit:\u003c\/strong\u003e\n    All three handsets share the same battery bay dimensions, connector pinout, and 3.7V supply rail. One replacement battery covers the entire group without any adapter or wiring change.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through charge and discharge cycles on a DECT 3749 unit. The BMS accepted the charge handshake from the base station immediately, with no error indication on the charging LED.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst charge on a Li-ion DECT handset:\u003c\/strong\u003e\n    Place the handset in the base cradle immediately after installing this battery and leave it there until the charge indicator clears. Li-ion cells shipped in storage state need an uninterrupted first charge to calibrate the fuel gauge in the handset firmware — pulling it early can cause the battery indicator to read inaccurately for several cycles.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eTalk time shorter than original after fitting the new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA new Li-ion cell ships partially charged — typically between 30% and 50% — and the handset's internal fuel gauge is not yet calibrated to the new cell's curve. This makes the battery indicator drop faster than the actual charge level warrants. Run two to three full charge and discharge cycles in normal use. After that, the gauge recalibrates and reported talk time stabilises at the rated 1100mAh level.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eDECT 3749 losing pairing after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eRemoving the battery cuts all power to the handset's volatile memory, which can erase the stored DECT pairing data on some firmware versions. The handset powers on normally but fails to register with the base, showing an unregistered or no-service state. To fix this, re-run the handset registration procedure from the base station admin menu — on most Avaya DECT systems this requires holding the registration button on the base for three seconds until the LED flashes. Once re-registered, the handset reconnects and retains the pairing through subsequent battery swaps.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339891998810,"sku":"BWCS-AYD749CL-1","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339892031578,"sku":"BWCS-AYD749CL-2","price":35.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339892064346,"sku":"BWCS-AYD749CL-3","price":38.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-AYD749CL-1.webp?v=1778366906","url":"https:\/\/batteryweb.com\/products\/avaya-dect-3749-replacement-battery-37v-1100mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}