{"product_id":"qiku-360-n4s-replacement-battery-385v-4900mah-li-polymer","title":"Qiku 360 N4S QK-394 Replacement Battery 3.85V 4900mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eQiku 360 N4S — 3.85V Li-Polymer Replacement Battery (QK-394)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.85V, 4900mAh Li-Polymer replacement battery for the Qiku 360 N4S smartphone (model 1505-A01). It matches the OEM part number QK-394 and fits the original battery cavity without modification. Rated at 18.87Wh, it restores full power operation to the handset.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e360 N4S \/ 1505-A01 fitment:\u003c\/strong\u003e\n    Both model designations share the same battery bay dimensions (84.90 × 66.80 × 4.90mm), the same 3.85V nominal voltage rail, and the same BMS connector pinout — so one cell covers all variants without adapter or modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge, standby load, and screen-on draw. The BMS accepted the charge handshake correctly, cutoff at full cell voltage, and held steady voltage under sustained modem load without false low-battery trips.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first install:\u003c\/strong\u003e\n    After fitting this cell, disable fast charging and run one full discharge-charge cycle at standard current. This gives the fuel gauge IC time to map the new cell's discharge curve before fast charge pushes higher 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 360 N4S reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe 360 N4S uses a coulomb-counting fuel gauge IC that builds its charge model around the original cell's internal resistance and discharge curve. Swap in a new cell and that model is stale — the IC reads voltage offsets from the old curve and outputs inaccurate percentages. The gauge corrects itself by tracking a full discharge from 100% down to automatic shutoff and then a complete charge back to 100%. One full cycle is usually enough to anchor the new discharge curve in the IC's memory.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC has not yet recalibrated to the new cell — it miscalculates remaining capacity and the phone hits the hardware voltage floor before the displayed percentage reaches zero. Screen-on load and active modem use draw peak current, which causes a sharp voltage sag on a fresh cell the IC hasn't characterised yet. Run the device down to automatic shutoff without interrupting the discharge, then charge uninterrupted to 100%. After that cycle, the gauge anchors correctly and the premature shutdowns stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392078905434,"sku":"BWCS-KKL410SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392078938202,"sku":"BWCS-KKL410SL-2","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392078970970,"sku":"BWCS-KKL410SL-3","price":33.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KKL410SL-1.webp?v=1779143621","url":"https:\/\/batteryweb.com\/products\/qiku-360-n4s-replacement-battery-385v-4900mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}