{"product_id":"fitbit-one-replacement-battery-37v-60mah-li-polymer","title":"FitBit One 3.7V 60mAh Li-Polymer Compatible Battery LSSP281324AB","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFitBit One — 3.7V Li-Polymer Replacement Battery (LSSP281324AB)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 60mAh Li-Polymer cell for the FitBit One clip-on fitness tracker. It replaces part number LSSP281324AB when the original cell can no longer hold enough charge for normal daily use. The FitBit One is a compact device with tight dimensional tolerances — this cell measures 20.30 x 12.90 x 4.20mm to match the original.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFitBit One fit:\u003c\/strong\u003e\n    The One uses a dedicated clip housing with a fixed battery bay. The LSSP281324AB footprint is specific to this model — the connector orientation and cell dimensions are not shared with other FitBit clip-on variants.\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 One platform. The BMS accepted the new cell without fault flags, and the fuel gauge IC responded correctly once a full charge cycle was completed from near-zero.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-swap charging protocol for the FitBit One:\u003c\/strong\u003e\n    Place the device on its charging cradle immediately after fitting this cell and charge to 100% before use. The fuel gauge IC on the One loses its reference point when the cell is swapped — skipping this step causes the percentage readout to stay at 0% or report inaccurately for days.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the FitBit One sleep tracking drains this cell faster than step counting\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eSleep tracking on the One keeps the accelerometer active through the night in a continuous logging state, rather than the lower-power polling mode used during daytime step counting. On a 60mAh cell, that sustained draw is proportionally significant. If you enable sleep tracking every night, expect shorter intervals between charges compared to step-only use. Turning off sleep tracking when you are not actively monitoring it is the most direct way to extend time between charges on this platform.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eFitBit One showing 0% and not powering on after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a fuel gauge IC calibration loss, not a faulty cell. When the original battery is removed, the IC loses its charge reference entirely and defaults to 0% or refuses to boot. Place the One on its charging cradle straight after fitting the new cell and leave it until the indicator shows a full charge. Do not attempt to power it on mid-charge to check progress. Once it reaches 100%, the IC re-establishes its reference and the device boots normally.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416168923226,"sku":"BWCS-FTN100SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416168955994,"sku":"BWCS-FTN100SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416168988762,"sku":"BWCS-FTN100SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FTN100SL-1.webp?v=1779760548","url":"https:\/\/batteryweb.com\/products\/fitbit-one-replacement-battery-37v-60mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}