{"product_id":"microsoft-lumia-950-xl-replacement-battery-39v-2950mah-li-ion","title":"Microsoft Lumia 950 XL BV-T4D Replacement Battery 3.9V 2950mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMicrosoft Lumia 950 XL — 3.9V Li-ion Replacement Battery (BV-T4D)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.9V, 2950mAh Li-ion cell built to the BV-T4D specification for the Lumia 950 XL and Lumia 950 XL Dual SIM (also sold as Cityman). It replaces the original battery when the cell has degraded, won't hold a charge, or the phone refuses to power on. Voltage, dimensions, and connector match the OEM spec exactly at 80.40 × 64.00 × 4.40mm.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eLumia 950 XL, 950 XL Dual SIM, and Cityman fit:\u003c\/strong\u003e\n    All three share the same physical housing, connector pinout, and BMS handshake protocol. The BV-T4D spec covers the full voltage rail from 4.35V charged down to the 3.0V cutoff the phone's charge IC expects.\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 Lumia 950 XL unit. The BMS communicated correctly with the phone's fuel gauge IC and accepted both standard and Qualcomm Quick Charge cycles without tripping overcurrent cutoff.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On the first cycle after installation, disable fast charging and run one full discharge down to auto-shutdown, then charge to 100% uninterrupted. This lets the coulomb counter recalibrate against the new cell's actual discharge curve before high-current charging begins.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the Lumia 950 XL after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Lumia 950 XL's Snapdragon 810 modem and QHD display pull current spikes that can expose a voltage cliff in a new or aged cell. When the cell voltage drops sharply under that load — even briefly — the phone's protection circuit cuts power before the displayed percentage reaches zero. This is not a faulty battery; it is the fuel gauge IC working from a discharge curve mapped to the old cell. One full uninterrupted discharge-to-shutdown followed by a full charge corrects the curve and pushes the cutoff point back down below 10%.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eUSB-PD fast charge not activating on the first cycle after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Lumia 950 XL negotiates USB-PD charging through the battery's BMS on the first connection. With a new cell, the BMS starts in a conservative state and may reject the higher voltage contract until it completes one standard-rate charge cycle. If fast charge shows as inactive in the battery settings screen, charge once at standard rate via a non-PD 5V adapter. On the next connection to a USB-PD charger, the BMS handshake completes and the phone should accept up to the full 3A charge rate.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392099418202,"sku":"BWCS-NK950SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392099450970,"sku":"BWCS-NK950SL-2","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392099483738,"sku":"BWCS-NK950SL-3","price":33.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NK950SL-1.webp?v=1779143764","url":"https:\/\/batteryweb.com\/products\/microsoft-lumia-950-xl-replacement-battery-39v-2950mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}