{"product_id":"lg-watch-urbane-replacement-battery-38v-400mah-li-polymer","title":"LG Watch Urbane BL-S3 Replacement Battery 3.8V 400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLG Watch Urbane \/ W150 — 3.8V Li-Polymer Replacement Battery (BL-S3)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.8V, 400mAh Li-Polymer cell that replaces the original BL-S3 in the LG Watch Urbane (W150). It fits the cavity dimensions of that watch exactly — 30.90 × 27.50 × 6.50mm — and connects to the same flex connector on the main board. Swap it in when the original cell no longer holds charge through a normal day of use.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWatch Urbane \/ W150 fitment:\u003c\/strong\u003e\n    Both model designations use the same chassis, the same flex connector pinout, and the same BMS handshake — one cell covers both. The BL-S3 part number is the identifier that matters; LG used it across the W150 lineup regardless of regional naming.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell on a W150 unit and confirmed the BMS accepted the new cell without fault flags. The fuel gauge IC re-initialised cleanly on the first full charge cycle after swap.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-swap charge protocol for the Urbane:\u003c\/strong\u003e\n    After fitting this cell, place the watch on its magnetic charger immediately and run a full charge to 100% before turning it on. The MAX17048 fuel gauge IC on the W150 loses its state-of-charge reference when power is removed — it cannot recalibrate without a complete charge cycle starting from near-zero. Skip this step and the percentage readout will be inaccurate 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 W150 fuel gauge reads 0% immediately after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe LG Watch Urbane uses a Maxim MAX17048 coulomb-counter IC to track state of charge. When you disconnect the original cell, the IC loses its learned voltage-to-capacity curve entirely. The new cell may sit at 3.75V — physically around 50% charge — but the IC has no reference and defaults to 0% or a random low value. A full charge cycle from the moment of installation resets the IC's endpoints and restores accurate readings. Do not trust the percentage until that first full charge completes.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eAlways-on display and continuous heart rate monitoring cutting charge life to under a day\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe W150's AMOLED panel in always-on mode draws roughly 15–20mA continuously — a significant fraction of a 400mAh cell on its own. Stack continuous heart rate polling on top and the combined draw can exceed 30mA sustained. A new cell at full 400mAh capacity will still drain faster than expected under this load profile. Disable always-on display and set heart rate monitoring to periodic rather than continuous in the LG Watch Manager app — that alone recovers meaningful capacity per charge cycle.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416167317594,"sku":"BWCS-LGW150SH-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416167350362,"sku":"BWCS-LGW150SH-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416167383130,"sku":"BWCS-LGW150SH-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LGW150SH-1.webp?v=1779760565","url":"https:\/\/batteryweb.com\/products\/lg-watch-urbane-replacement-battery-38v-400mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}