{"product_id":"asus-zenfone-pegasus-4a-replacement-battery-385v-4050mah-li-polymer","title":"Asus ZenFone Pegasus 4A C11P1610 Compatible Battery 3.85V","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAsus ZenFone Pegasus 4A \/ ZB500TL — 3.85V Li-Polymer Replacement Battery (C11P1610)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.85V, 4050mAh (15.59Wh) Li-Polymer cell for the Asus ZenFone Pegasus 4A and ZB500TL smartphones. It replaces OEM part C11P1610 (1ICP5\/62\/74) and fits the same physical bay with the same connector orientation. Use this when the original cell no longer holds a charge, swells, or causes unexpected shutdowns.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eZenFone Pegasus 4A and ZB500TL compatibility:\u003c\/strong\u003e\n    Both models run the same 3.85V battery rail, share the same connector pinout, and use the same BMS handshake protocol — one cell covers both variants 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 charge and discharge on ZB500TL hardware. The BMS accepted charge from cold, balanced cells correctly under screen-on load, and held voltage above the shutdown threshold throughout the discharge curve.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On first use after installation, disable fast charging and run one full discharge-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before fast charge pushes higher current into an uncalibrated cell — skipping this step causes the percentage readout to drift or jump.\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 ZenFone Pegasus 4A after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA new Li-Polymer cell has a slightly different voltage-to-capacity curve than the degraded cell the fuel gauge IC was calibrated against. When the phone hits a load spike — modem transmit, screen wake, or GPS — the cell voltage drops briefly below the shutdown threshold even though the displayed percentage reads 20–30%. The phone interprets this as a critical undervoltage event and cuts power instantly. One full discharge-charge cycle at standard current gives the coulomb counter enough data to remap the curve and move the shutdown trigger to the correct voltage.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eUSB fast charge not activating on the first cycle after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eAfter a cell swap, the charge IC on the ZB500TL sometimes defaults to trickle or standard 5V charging on the first cycle — it does not immediately negotiate the fast-charge protocol with a new, uncalibrated BMS. This is normal behaviour and not a fault with the replacement cell. Complete one full standard-current cycle first. On the second charge, fast charging should re-engage; if it does not, check that the charger output is at least 5V\/2A and the cable supports data lines.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391995871322,"sku":"BWCS-AUP400SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391995904090,"sku":"BWCS-AUP400SL-2","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391995936858,"sku":"BWCS-AUP400SL-3","price":33.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-AUP400SL-1.webp?v=1779142856","url":"https:\/\/batteryweb.com\/products\/asus-zenfone-pegasus-4a-replacement-battery-385v-4050mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}