{"product_id":"bose-qc3-replacement-battery-37v-200mah-li-ion","title":"Bose QC3 40229 Replacement Battery 3.7V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBose QuietComfort 3 — 3.7V Li-ion Replacement Battery (40229)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 200mAh Li-ion cell for the Bose QuietComfort 3 headphones. It powers both the active noise cancellation circuit and the audio amplifier inside the QC3 earcup. Fit models include QC3 units referenced under OEM numbers 40229 and 40228.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eQC3 compatibility — OEM cross-reference:\u003c\/strong\u003e\n    The 40229 and 40228 listings share the same cell footprint, voltage rail, and connector orientation. The BMS in the QC3 housing does not require a proprietary handshake, so the cell seats and charges from the original Bose cable without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through charge-discharge cycles on a QC3 unit, monitoring the BMS cutoff at both ends. The cell accepted a full charge without thermal event, and the low-voltage cutoff triggered correctly before cell damage could occur.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-charge protocol for the QC3:\u003c\/strong\u003e\n    The QC3 ships replacement cells at storage voltage, around 3.6V. Plug the headset into the Bose charging cable and let it complete one uninterrupted charge cycle before use — this allows the onboard circuit to register the new cell's actual capacity baseline.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the QC3 cuts out mid-listen after a battery swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe QC3 draws current from two separate loads simultaneously — the audio amplifier and the active noise cancellation circuit. Under combined draw, a new cell at storage voltage can sag below the BMS cutoff threshold, triggering a shutdown that looks like a dead battery. This is not a faulty cell. One full charge cycle from the Bose cable resolves it. After that first cycle, the cell stabilises under combined load and cutouts stop.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eQC3 showing full charge on the indicator but cutting off after a few tracks\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the cell arrives at storage voltage (roughly 3.6V) and the QC3's charge indicator reads that as \"full\" before a proper charge cycle has run. The indicator is calibrated to the cell's state of charge, not its actual capacity. The fix is straightforward — connect to the Bose charging cable and let the LED cycle through to a confirmed full charge, which typically brings the cell to 4.2V. After that first complete cycle, the indicator and actual capacity align.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43428158931034,"sku":"BWCS-BQC3SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43428158963802,"sku":"BWCS-BQC3SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43428158996570,"sku":"BWCS-BQC3SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BQC3SL_1.webp?v=1779934277","url":"https:\/\/batteryweb.com\/products\/bose-qc3-replacement-battery-37v-200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}