{"product_id":"cobra-an-8521-replacement-battery-36v-250mah-ni-mh","title":"Cobra AN-8521 Replacement Battery 3.6V 250mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCobra AN-8521 \/ CP-479 Series — 3.6V Ni-MH Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.6V 250mAh Ni-MH replacement battery for the Cobra AN-8521, CP-479, CP-479S, and CP-480 cordless phone handsets. It slots into the handset battery compartment and powers the DECT radio and audio circuits. Voltage and cell count match the original Cobra pack exactly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eAN-8521 and CP-479 series compatibility:\u003c\/strong\u003e\n    These handsets share the same 3.6V three-cell Ni-MH battery bay, connector orientation, and charge acceptance circuit. One pack covers the full model group without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this pack through the Cobra charge circuit and confirmed the base station accepted the battery without throwing a charge error. The BMS handshake completed normally across multiple charge cycles.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-charge conditioning for Ni-MH handsets:\u003c\/strong\u003e\n    After installing, seat the handset in the base and leave it for a full 16 hours before the first call. Ni-MH cells in cordless phones need a slow initial charge to reach rated capacity — skipping this shortens usable talk time from the first cycle.\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 rated after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH cells ship in a partial-discharge state. On the first few cycles, the cell chemistry hasn't fully activated, so measured capacity runs below the 250mAh rating. This is normal and not a fault with the pack. Capacity builds over three to five full charge-discharge cycles until the cells stabilise at rated output. If talk time is still short after five cycles, check that the handset is seated squarely in the base — a misaligned contact drops the charge current.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBase station shows no-charge or error light with new pack\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eCobra base stations check incoming battery voltage before starting the charge cycle. A Ni-MH pack that has self-discharged during storage can arrive below the acceptance threshold — typically under 3.0V — and the base reads this as a fault rather than a flat battery. Remove the handset, wait 30 seconds, and reseat it firmly. If the error persists, use a separate Ni-MH charger to bring the pack above 3.2V, then return it to the base for a normal charge cycle.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339930796122,"sku":"BWCS-CPB479CL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339930828890,"sku":"BWCS-CPB479CL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339930861658,"sku":"BWCS-CPB479CL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CPB479CL_1.webp?v=1778366983","url":"https:\/\/batteryweb.com\/products\/cobra-an-8521-replacement-battery-36v-250mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}