{"product_id":"caire-inc-airsep-freestyle-3-replacement-battery-148v-3600mah-li-ion","title":"Caire Inc AirSep Freestyle 3 Compatible Battery 14.8V 3600mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCaire Inc AirSep Freestyle 3 — 14.8V Li-ion Replacement Battery (BT015-1)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 14.8V, 3600mAh lithium-ion battery replaces OEM part numbers BT015-1 and BT018-1S in the AirSep Freestyle 3 and Freestyle 5 portable oxygen concentrators. It powers the concentrator during mobile use when patients need oxygen therapy away from a stationary oxygen source. Voltage and capacity match the original cell specifications for these units.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFreestyle 3 and Freestyle 5 platform:\u003c\/strong\u003e\n    Both models run the same 14.8V four-cell Li-ion architecture and share a common BMS handshake protocol, which is why BT015-1 and BT018-1S cross-reference across the platform. The connector pinout and BMS communication lines are identical between units.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through the Freestyle 3 charge-discharge sequence and confirmed the BMS completed capacity registration without triggering a fault code. Charge acceptance matched the OEM profile across the full voltage window from 12.0V to 16.8V.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePower-on self-test protocol:\u003c\/strong\u003e\n    After installing this battery, let the device complete its full startup self-test sequence without powering it off. Medical-grade concentrators run a BMS verification step at boot — interrupting it locks in a false battery fault that will not clear until the next complete power cycle from rest.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Freestyle 3 alarms low battery with a freshly charged replacement installed\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Freestyle 3 BMS stores a learned capacity model from the previous cell. When a new cell arrives with a different internal resistance profile, the BMS reads the discharge curve as shallower than expected and flags it as low before the actual state of charge drops. This is a calibration issue, not a fault with the battery itself. One full charge-to-discharge cycle on the new cell resets the learned model and clears the alarm behaviour. Run that cycle before clinical use.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eFreestyle 3 not completing boot sequence after battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eIf the concentrator stalls mid-boot after fitting this battery, the cell voltage at rest is likely sitting below the BMS boot-admission threshold — typically around 12.5V — after storage. The BMS interprets sub-threshold voltage as an unsafe or depleted cell and halts the startup sequence as a protective measure. Connect the unit to mains power first and allow a 15-minute pre-charge before attempting to boot on battery alone. Once resting voltage climbs above 13.0V, the boot sequence completes normally.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381416951898,"sku":"BWCS-SPF300MD-1","price":101.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381416984666,"sku":"BWCS-SPF300MD-2","price":119.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381417017434,"sku":"BWCS-SPF300MD-3","price":133.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SPF300MD-1.webp?v=1778900681","url":"https:\/\/batteryweb.com\/products\/caire-inc-airsep-freestyle-3-replacement-battery-148v-3600mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}