{"product_id":"fossil-julianna-hr-ftw6035-replacement-battery-38v-300mah-li-polymer","title":"Fossil Julianna HR FTW6035 Replacement Battery 3.8V 300mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFossil Julianna HR FTW6035 — 3.8V Li-Polymer Replacement Battery (APP00296)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.8V, 300mAh lithium-polymer cell is a direct replacement for the Fossil Julianna HR FTW6035 smartwatch. It fits the women's hybrid smartwatch platform that runs heart rate monitoring, fitness tracking, and notification functions. Dimensions are 28.70 × 23.60 × 3.80mm — verify against the original cell before fitting.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eJulianna HR FTW6035 fitment:\u003c\/strong\u003e\n    The FTW6035 uses a compact Li-Polymer cell constrained by the watch's slim case profile. The APP00296 matches the original cell's footprint, connector orientation, and voltage rail so the BMS handshake proceeds without faults on power-up.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge and discharge on a smartwatch test rig. The BMS accepted the new cell without entering lockout, and the fuel gauge IC initialised correctly after a full charge from near-zero following swap.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge calibration after swap:\u003c\/strong\u003e\n    Place the watch on its magnetic charger immediately after fitting the new cell. Let it charge to 100% before first use. The fuel gauge IC on the FTW6035 cannot set its reference point without a complete charge cycle from near-depletion — skipping this step causes the percentage display to read incorrectly 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 FTW6035 shows 0% immediately after a battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Julianna HR uses a fuel gauge IC that stores a learned charge reference in volatile memory. When the cell is disconnected, that reference is lost. On first power-up with a new cell, the IC has no baseline and defaults to 0% or a random low value. This is not a fault with the replacement cell. Charge the watch to 100% uninterrupted before using it — the IC resets its calibration at the top of the charge curve.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWatch not pairing to phone after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eRemoving power during a battery swap terminates the active BLE session between the watch and the paired phone. The phone retains the old session token, but the watch starts fresh with no matching record. The watch will not reconnect automatically in this state. Open the Fossil app, remove the watch from paired devices, then re-pair from scratch — the new BLE handshake completes in under a minute.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416153489498,"sku":"BWCS-FTW603SH-1","price":38.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416153522266,"sku":"BWCS-FTW603SH-2","price":45.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416153555034,"sku":"BWCS-FTW603SH-3","price":49.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FTW603SH-1.webp?v=1779760505","url":"https:\/\/batteryweb.com\/products\/fossil-julianna-hr-ftw6035-replacement-battery-38v-300mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}