{"product_id":"infinix-zero-5-replacement-battery-38v-2700mah-li-polymer","title":"Infinix Zero 5 BL-43AX Replacement Battery 3.8V 2700mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eInfinix Zero 5 \/ X603 — 3.8V Li-Polymer Replacement Battery (BL-43AX)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.8V, 2700mAh Li-Polymer replacement cell for the Infinix Zero 5 (X603). It slots into the same position as the original BL-43AX and connects to the same flex ribbon contacts on the motherboard. Use it when the original cell no longer holds charge through a normal day of calls, browsing, and screen-on time.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eZero 5 and X603 compatibility:\u003c\/strong\u003e\n    Both model designations reference the same hardware platform. The BL-43AX connector, cell footprint (86.40 × 69.64 × 3.42mm), and BMS handshake spec are identical across both variants — no adapter or modification needed.\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 Zero 5 platform. The BMS accepted the cell without fault codes, the charge IC ramped current correctly, and the fuel gauge began tracking state-of-charge after one full cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After fitting this cell, disable fast charging for the first complete discharge-to-charge cycle. The fuel gauge IC on the Zero 5 is calibrated to the discharge curve of the original cell. One slow cycle lets the coulomb counter re-anchor its zero and full points against the new cell 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\"\u003eWhy the Zero 5 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Zero 5 uses a fuel gauge IC that builds its state-of-charge model from repeated discharge data on the original cell. When you fit a new cell, the IC still references the old discharge curve. This mismatch causes the percentage readout to jump, freeze, or report full charge at a lower actual capacity. One full slow discharge followed by a full slow charge forces the coulomb counter to relearn the new cell's voltage-to-capacity relationship. After that cycle, percentage reporting stabilises.\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 modem radio, display, or both pull current that the cell cannot sustain at its present state of charge — voltage drops below the BMS cutoff threshold even though the UI shows charge remaining. On a new, uncalibrated cell, the fuel gauge IC underestimates how quickly voltage falls under load. The fix is the same recalibration cycle: one full discharge to automatic shutdown, then a full charge without interruption. If shutdowns continue past two cycles, check that the battery flex connector is fully seated — a partial contact raises internal resistance and worsens voltage sag under load.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391942328410,"sku":"BWCS-FNX603SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391942361178,"sku":"BWCS-FNX603SL-2","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391942393946,"sku":"BWCS-FNX603SL-3","price":33.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FNX603SL-1.webp?v=1779142677","url":"https:\/\/batteryweb.com\/products\/infinix-zero-5-replacement-battery-38v-2700mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}