{"product_id":"huawei-band-7-replacement-battery-387v-180mah-li-polymer","title":"Huawei Band 7 Replacement Battery HB351731EFW 3.87V 180mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHuawei Band 7 \/ Band 6 Series — 3.87V Li-Polymer Replacement Battery (HB351731EFW)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 180mAh (0.7Wh) 3.87V lithium-polymer cell that replaces the OEM HB351731EFW battery in the Huawei Band 7, Band 6, and Band 6 Pro. It restores power to the display, optical heart rate sensor, and activity tracking modules. Physical dimensions are 29.40 × 16.30 × 3.40mm — confirm clearance before ordering if your unit has been previously repaired.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBand 7, Band 6, Band 6 Pro compatibility:\u003c\/strong\u003e\n    All three models share the HB351731EFW cell format, the same 3.87V charging rail, and an identical footprint. The BMS termination voltage and charge curve are consistent across the group, so one cell covers all three.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran the HB351731EFW on the Band 7 platform and confirmed the BMS accepted the cell without a fault flag. Charge termination triggered correctly at 4.35V, and the fuel gauge IC updated its state-of-charge reading after a full charge cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-swap charge requirement:\u003c\/strong\u003e\n    After fitting this cell, place the watch on its magnetic charger immediately and charge to 100% before first use. The fuel gauge IC on this platform loses its calibration reference when the original cell is disconnected. Without a full charge cycle from near-zero, the percentage readout will be unreliable.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSmartwatch showing 0% immediately after battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the fuel gauge IC — a small dedicated chip separate from the main SoC — stores a learned charge table for the old cell. When the cell is swapped, that reference is gone and the IC defaults to 0% or shows a flat, incorrect readout. The fix is straightforward: connect the watch to its charger right after reassembly and let it charge to 100% without interruption. Once the gauge IC completes a full cycle from near-zero, it recalibrates against the new cell's actual capacity. After that first full charge, the percentage display will track correctly.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWatch not pairing with the phone app after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eRemoving the battery cuts power to the Bluetooth controller and clears its active session keys. The Huawei Health app holds the old session in memory and may show the device as connected while the watch itself sees no active pairing. Open the Huawei Health app, go to device settings, tap \"Unpair device,\" then initiate a fresh pairing from the Band's Bluetooth menu. The watch must be fully powered on — not just showing the boot logo — before the pairing handshake will complete.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416151523418,"sku":"BWCS-HNR008SH-1","price":33.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416151556186,"sku":"BWCS-HNR008SH-2","price":39.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416151588954,"sku":"BWCS-HNR008SH-3","price":43.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HNR008SH-1.webp?v=1779760467","url":"https:\/\/batteryweb.com\/products\/huawei-band-7-replacement-battery-387v-180mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}