{"product_id":"tp-link-neffos-x1-replacement-battery-385v-2150mah-li-polymer","title":"TP-Link Neffos X1 Replacement Battery 3.85V 2150mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eTP-Link Neffos X1 \/ TP902C — 3.85V Li-Polymer Replacement Battery (NBL-38A2250)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.85V, 2150mAh (8.28Wh) Li-Polymer battery for the TP-Link Neffos X1, Neffos X1 Dual SIM, and TP902C smartphones. It replaces OEM part NBL-38A2250 directly. Fits the same connector and cell footprint as the factory-installed unit.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eNeffos X1 and TP902C compatibility:\u003c\/strong\u003e\n    Both the standard and Dual SIM variants of the Neffos X1 share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell fits all three listed models 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 full charge and discharge on a Neffos X1 unit. The BMS accepted the handshake on first connection, charge IC ramped to CC\/CV without fault codes, and the fuel gauge IC tracked state-of-charge accurately after one calibration cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge reset:\u003c\/strong\u003e\n    After fitting this battery, disable fast charging in the phone's settings and run one complete discharge-to-charge cycle at standard current. This lets the fuel gauge IC map its coulomb counter against the new cell's discharge curve before high-current charging loads an uncalibrated cell.\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 Neffos X1 after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA new cell has a slightly different internal resistance profile than the worn cell the fuel gauge IC was calibrated to. Under high-draw moments — modem transmit burst, screen-on at full brightness — the new cell's voltage briefly sags below the BMS cutoff threshold even while the OS still reports 20–30% remaining. The phone reads the coulomb counter, not live voltage, so it doesn't see the cliff coming. One full discharge cycle from 100% down to auto-off, followed by an uninterrupted charge to 100%, resets the coulomb counter baseline and resolves the premature shutdowns.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone won't power on after the replacement battery sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-Polymer cells self-discharge during storage. If this battery shipped or sat at a voltage below approximately 2.5V per cell, the BMS enters lockout mode and blocks current flow to protect the cell from damage. The phone will show no response — no boot screen, no charge indicator. Connect the phone to a wall charger rated at least 5V\/1A and leave it for 15–20 minutes without pressing the power button. The charge IC trickle-charges the cell until BMS lockout clears, typically around 3.0V, after which the phone will show the charging animation and boot normally.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392039190618,"sku":"BWCS-TPX100SL-1","price":29.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392039223386,"sku":"BWCS-TPX100SL-2","price":33.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392039256154,"sku":"BWCS-TPX100SL-3","price":36.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-TPX100SL-1.webp?v=1779143086","url":"https:\/\/batteryweb.com\/products\/tp-link-neffos-x1-replacement-battery-385v-2150mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}