{"product_id":"honor-hes-b09-replacement-battery-387v-180mah-li-polymer","title":"Honor HB351731EFW Smartwatch Compatible Battery 3.87V 180mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHonor HES-B09 \/ Watch ES — 3.87V Li-Polymer Replacement Battery (HB351731EFW)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThe HB351731EFW is a 3.87V, 180mAh Li-Polymer cell for the Honor HES-B09 and Watch ES smartwatches. It replaces the original cell when charge retention has dropped noticeably after months of daily wear. Dimensions are 29.40 × 16.30 × 3.40mm — verify these against the existing cell before fitting.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eHES-B09 and Watch ES compatibility:\u003c\/strong\u003e\n    Both watches use the same connector pinout, BMS handshake protocol, and physical footprint, so one cell covers both platforms without modification.\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 the HES-B09 board and confirmed the BMS accepted the cell, balanced charge current correctly at full capacity, and did not throw a protection cutoff under normal sensor load.\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 run a full charge to 100% before wearing it. The fuel gauge IC on the HES-B09 loses its reference point when the cell is disconnected and cannot recalibrate without a complete 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 the HES-B09 shows 0% and refuses to boot after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe HES-B09 uses a coulomb-counting fuel gauge that stores state-of-charge data in volatile memory. When you disconnect the original cell, that reference is wiped. The watch then reads the new cell's open-circuit voltage as an unknown state and defaults to 0%, which can prevent the boot sequence from completing. Placing the watch on charge immediately after reassembly forces the fuel gauge to re-initialise against a known endpoint. Once the charger confirms 100%, the gauge is recalibrated and the watch boots normally.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBLE pairing lost after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eRemoving the battery cuts power to the BLE stack entirely, which clears the active session key between the watch and the paired phone. The phone retains the old pairing record but the watch no longer recognises it. Go into your phone's Bluetooth settings, forget the Honor watch entry, then re-pair through the Hihonor app from scratch. The watch must be fully booted and showing a charge percentage above 10% before the pairing handshake completes reliably.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416151425114,"sku":"BWCS-HNR008SH-1","price":33.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416151457882,"sku":"BWCS-HNR008SH-2","price":39.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416151490650,"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\/honor-hes-b09-replacement-battery-387v-180mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}