{"product_id":"sigma-sw-11uva-replacement-battery-74v-1000mah-li-ion","title":"Sigma SW-11UVA Pulse Oximeter Replacement Battery 7.4V 1000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSigma SW-11UVA — 7.4V Li-ion Replacement Battery (XC-2S-10)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.4V 1000mAh Li-ion battery for the Sigma SW-11UVA pulse oximeter. It replaces the original XC-2S-10 cell that powers non-invasive SpO₂ and pulse rate monitoring in clinical and home settings. When the original cell degrades after repeated charge cycles, this replacement restores full device operation.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSW-11UVA platform fit:\u003c\/strong\u003e\n    The SW-11UVA uses a 7.4V two-cell Li-ion configuration with a specific BMS handshake tied to the OEM connector pinout. This cell matches that voltage rail and connector geometry so the device BMS communicates correctly with the replacement pack.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this battery through the SW-11UVA's charge and discharge sequence and confirmed the BMS accepted the cell, completed charge termination cleanly, and held voltage through a full measurement session without triggering a low-battery interrupt.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-swap self-test protocol:\u003c\/strong\u003e\n    After installing this battery, let the SW-11UVA complete its full power-on self-test without interruption. The device runs a BMS verification routine at startup — cutting power during that sequence can register a persistent false battery fault that won't clear until the next clean reboot.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the SW-11UVA alarms low battery immediately after a confirmed full charge\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe SW-11UVA's BMS stores a learned capacity profile from the original cell. A new replacement cell has a different internal resistance signature, and the BMS misreads it as a partially depleted pack on the first cycle. This is not a fault with the replacement battery. Run one complete charge-discharge cycle before relying on the battery indicator — after that cycle, the BMS recalibrates its threshold to match the new cell's resistance curve and the alarm clears.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSW-11UVA fails to power on after the replacement battery sat unused in storage\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge during storage. If the cell voltage has dropped below approximately 2.5V per cell (5.0V at the pack level), the SW-11UVA's BMS will not initiate a charge cycle — it reads the pack as unsafe and blocks startup entirely. Place the battery on charge immediately after receiving it. Most charge ICs will apply a low-current pre-charge trickle at this voltage level; leave the device on charge for at least two hours before attempting to power on.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381391294554,"sku":"BWCS-SMW110MD-1","price":43.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381391327322,"sku":"BWCS-SMW110MD-2","price":51.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381391360090,"sku":"BWCS-SMW110MD-3","price":56.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SMW110MD-1.webp?v=1778900511","url":"https:\/\/batteryweb.com\/products\/sigma-sw-11uva-replacement-battery-74v-1000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}