{"product_id":"neffos-y5-replacement-battery-385v-2050mah-li-polymer","title":"Neffos Y5 NBL-39A2130 Replacement Battery 3.85V 2050mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eNeffos Y5 \/ TP802A Series — 3.85V Li-Polymer Replacement Battery (NBL-39A2130)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.85V, 2050mAh Li-Polymer battery for the Neffos Y5, TP802A-3, and TP802A smartphones. It replaces OEM part NBL-39A2130 when the original cell degrades or fails to hold a charge. Voltage and capacity match factory spec exactly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eY5 \/ TP802A platform fit:\u003c\/strong\u003e\n    The TP802A-3 and TP802A share the same 3.85V battery rail, connector pinout, and BMS handshake as the standard Y5. One replacement cell covers all three variants without wiring or adapter changes.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through a full discharge and charge on the Y5 platform. The BMS accepted the new cell on first contact, charge IC ramped to full current within seconds, and the protection circuit tripped correctly at the low-voltage cutoff threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge recalibration:\u003c\/strong\u003e\n    After fitting this cell, disable fast charging and run one complete discharge-to-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Y5 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Y5's fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual cell chemistry. The gauge reads state-of-charge against the old curve and outputs incorrect percentages. One full discharge below 5% followed by a complete charge to 100% forces the coulomb counter to reset and relearn against the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% remaining on the replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the modem or screen draws a current spike the cell cannot sustain without voltage dropping below the BMS cutoff threshold — even though the gauge still shows capacity remaining. The BMS trips to protect the cell, cutting power instantly. The fuel gauge IC hasn't yet learned the new cell's voltage-sag profile under load. Run two full discharge-charge cycles and confirm the phone is on firmware version that supports the NBL-39A2130 cell spec; charge to 100% and check open-circuit voltage reads at or above 4.35V before fitting back into service.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391989055578,"sku":"BWCS-TPY510SL-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391989088346,"sku":"BWCS-TPY510SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391989121114,"sku":"BWCS-TPY510SL-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-TPY510SL-1.webp?v=1779142786","url":"https:\/\/batteryweb.com\/products\/neffos-y5-replacement-battery-385v-2050mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}