{"product_id":"lenovo-thinkpad-x1-yoga-2018-replacement-battery-1536v-3500mah-li-polymer","title":"Lenovo ThinkPad X1 Yoga 2018 Replacement Battery L17C4P71 15.36V","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLenovo ThinkPad X1 Yoga 2018 — 15.36V Li-Polymer Replacement Battery (L17C4P71)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 15.36V, 3500mAh (53.76Wh) Li-Polymer battery for the Lenovo ThinkPad X1 Yoga 2018 2-in-1 convertible laptop. It replaces OEM part numbers L17C4P71, L17M4P71, SB10K97623, SB10K97624, and several others used across the 2018 X1 Yoga lineup. Fits 20LD-series variants including 20LD000KCD, 20LD000SCD, and 20LD000TCD.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e20LD-series compatibility:\u003c\/strong\u003e\n    All 2018 X1 Yoga 20LD variants share the same 15.36V four-cell Li-Polymer pack, connector pinout, and BMS handshake protocol — which is why multiple OEM part numbers cross-reference to a single physical cell configuration.\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 the ThinkPad platform. The BMS negotiated correctly with the EC firmware, reported state-of-charge without error flags, and held stable voltage through simulated CPU and display load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle calibration on X1 Yoga:\u003c\/strong\u003e\n    After fitting, run the laptop down to hibernate cutoff on battery power alone, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning the EC logs after every cell swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the X1 Yoga 2018 BIOS reports poor battery health after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ThinkPad embedded controller reads cycle count, charge history, and health data stored in the old cell's EEPROM. A new cell arrives with a blank or mismatched EEPROM, so the EC immediately flags it as degraded. This is a firmware classification issue, not a fault with the replacement cell. Running one full discharge-to-hibernate followed by an uninterrupted full charge gives the EC enough data to overwrite that flag and re-establish an accurate health baseline.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLaptop shuts down at 20–30% charge shown after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC in the new cell hasn't yet calibrated its voltage-to-capacity curve against your specific usage load. Under combined CPU and display draw, the cell voltage drops faster than the uncalibrated gauge predicts, and the EC triggers a protective shutdown before the displayed percentage reaches zero. This is not a faulty cell — it corrects itself over two to three full charge and discharge cycles. After calibration, the gauge stabilises and shutdowns stop occurring above 10–12% shown.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409720475738,"sku":"BWCS-LVX108NB-1","price":119.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409720508506,"sku":"BWCS-LVX108NB-2","price":137.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409720541274,"sku":"BWCS-LVX108NB-3","price":151.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LVX108NB-1.webp?v=1779580516","url":"https:\/\/batteryweb.com\/products\/lenovo-thinkpad-x1-yoga-2018-replacement-battery-1536v-3500mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}