{"product_id":"sennheiser-momentum-tw2-charging-case-replacement-battery-37v-700mah-li-ion","title":"Sennheiser Momentum TW2 Charging Case Battery 3.7V 700mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSennheiser Momentum TW2 Charging Case — 3.7V Li-ion Replacement Battery (14500CY-900)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V 700mAh Li-ion cell replaces the internal battery in the Sennheiser Momentum TW2 charging case. The case battery is what stores charge between wall outlet sessions and delivers it to the earbuds — when it degrades, the earbuds stop getting topped up mid-day. This replacement restores that between-charge buffer.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMomentum TW2 case fit:\u003c\/strong\u003e\n    The TW2 case uses a single cylindrical Li-ion cell rated at 3.7V to run its internal charge management circuit. The 14500CY-900 format matches the cell footprint, contact orientation, and voltage rail the case's charging IC expects.\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 the TW2 case platform. The onboard BMS accepted the new cell without error, completed a full charge cycle from depleted, and passed charge through to connected earbuds at the correct output voltage.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle case conditioning:\u003c\/strong\u003e\n    After fitting this cell, charge the case fully from empty before loading the earbuds. The TW2 case charge controller recalibrates its capacity estimate on the first full cycle — skipping this step causes the LED indicator to report inaccurate charge state for the first several uses.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the TW2 case LED shows full but earbuds go flat after one top-up\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe TW2 case measures its battery state by tracking voltage, not a coulomb counter. A new cell installed at storage voltage — typically around 3.6V — sits close enough to nominal that the case reports full. But the usable capacity window only unlocks after a complete charge-discharge cycle drives the cell through its full voltage range. Until that first full cycle runs, the case pulls charge from a narrow voltage band and exhausts it faster than the indicator suggests.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCase charging stops early and the amber light pulses without reaching solid white\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis symptom usually means the charge IC timed out before the cell reached termination voltage. It happens when a degraded or deeply discharged cell takes longer than the case's charge timer allows. With a fresh replacement cell starting from storage voltage, plug the case into the charger and leave it connected for a minimum of two hours without interruption. If the pulsing persists past that point, check the USB cable and source — the TW2 case requires a stable 5V input; underpowered sources cause the charge controller to abort early. Confirm input voltage is at 5.0V before suspecting the cell.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43428096802906,"sku":"BWCS-SHW200SL-1","price":33.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43428096835674,"sku":"BWCS-SHW200SL-2","price":39.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43428096868442,"sku":"BWCS-SHW200SL-3","price":43.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SHW200SL-1.webp?v=1779934086","url":"https:\/\/batteryweb.com\/products\/sennheiser-momentum-tw2-charging-case-replacement-battery-37v-700mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}