{"product_id":"stealth-400-replacement-battery-37v-900mah-li-polymer","title":"Stealth 400 Replacement Battery FT603048P 3.7V 900mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eStealth 400 \/ 500 Series — 3.7V Li-Polymer Replacement Battery (FT603048P)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 900mAh lithium-polymer cell built to the FT603048P specification. It fits the Stealth 400 and 500 wireless headsets. Swap it in when the original cell no longer holds a charge or drops out during calls.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e400 and 500 series compatibility:\u003c\/strong\u003e\n    Both models run the same 3.7V power rail, share the FT603048P cell footprint, and use the same BMS handshake with the base station — that's why one cell covers both.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge and discharge on the bench. The BMS held the cutoff voltage correctly at both ends and passed the charge-complete signal to the base station without fault.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle base station protocol:\u003c\/strong\u003e\n    Seat the headset in the base station and let it complete a full uninterrupted charge before taking a call. DECT headsets log the new cell during that first cycle — skipping it causes the talk-time indicator to report incorrectly until the handshake completes.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBase station not recognising the new pack after fitting\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eDECT base stations verify the battery pack through a BMS handshake before displaying a charge status. A cell shipped at storage voltage — typically around 3.6V — may not have enough charge for the base to initiate that exchange. Place the headset on the base immediately after fitting and leave it for a complete charge cycle without removing it. Once the handshake completes, the base will display charge status normally on every subsequent cycle.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eHeadset cuts out mid-call even with a charged battery\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Stealth 400 and 500 draw simultaneously from the audio circuit and the DECT radio during a live call. That combined load creates brief current spikes that can trip the BMS undervoltage cutoff if the cell voltage sags below threshold — even when the displayed charge level looks fine. This is most common in the first few cycles before the cell has settled. Run three to five full charge-and-use cycles and the sag behaviour typically stabilises as the cell reaches its rated 900mAh output.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43428133863514,"sku":"BWCS-STH400SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43428133896282,"sku":"BWCS-STH400SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43428133929050,"sku":"BWCS-STH400SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-STH400SL-1.webp?v=1779934246","url":"https:\/\/batteryweb.com\/products\/stealth-400-replacement-battery-37v-900mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}