{"product_id":"huawei-watch-3-pro-replacement-battery-385v-660mah-li-polymer","title":"Huawei Watch 3 Pro Compatible Battery HB642735ECW 3.85V 660mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHuawei Watch 3 Pro \/ Watch 3S \/ Watch 3X — 3.85V Li-Polymer Replacement Battery (HB642735ECW)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.85V, 660mAh Li-Polymer cell replaces the OEM battery in the Huawei Watch 3 Pro, Watch 3S, and Watch 3X smartwatches. It fits the original battery bay and connector without modification. Physical dimensions are 32.80 × 25.70 × 6.30mm — measure your existing cell before ordering if you are unsure.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWatch 3 Pro, 3S, and 3X compatibility:\u003c\/strong\u003e\n    All three models share the HB642735ECW cell format, the same connector pinout, and an identical fuel gauge IC interface. The BMS handshake is consistent across the series, so one cell covers all three 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 a Watch 3 Pro unit. The fuel gauge IC accepted the new cell, BMS protection tripped correctly at low-voltage cutoff, and charge termination behaved normally at full capacity.\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 this cell and charge it to 100% before first use. The fuel gauge IC on this platform loses its reference point when the cell is removed — it cannot report accurate state-of-charge until it completes one full charge cycle from near-zero.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy always-on display and continuous HR monitoring drain this cell faster than expected\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Watch 3 Pro draws current from three simultaneous sources when AOD and heart rate monitoring run together: the AMOLED panel, the optical HR sensor, and the GPS receiver during workouts. A new cell at a different impedance than the aged original will show a different discharge curve for the first several cycles. Current draw from the HR sensor is higher on a fresh cell because the sensor auto-adjusts gain against the new impedance profile. This normalises within five to seven charge cycles.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWatch not pairing with phone after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eRemoving the battery clears the active BLE session between the watch and the Huawei Health app. The watch does not automatically re-establish a paired connection after power is restored — it waits for the host device to initiate. On your phone, open Huawei Health, go to the device settings for the watch, tap \"Forget device,\" then re-add it from scratch. This resets the BLE handshake and resolves the pairing failure without a factory reset of the watch itself.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416157880410,"sku":"BWCS-HUP320SH-1","price":38.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416157913178,"sku":"BWCS-HUP320SH-2","price":45.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416157945946,"sku":"BWCS-HUP320SH-3","price":49.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HUP320SH-1.webp?v=1779760505","url":"https:\/\/batteryweb.com\/products\/huawei-watch-3-pro-replacement-battery-385v-660mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}