{"product_id":"fly-iq4514-replacement-battery-38v-1800mah-li-polymer","title":"Fly IQ4514 Replacement Battery BL3819 3.8V 1800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFly IQ4514 Quad EVO Tech 4 — 3.8V Li-Polymer Replacement Battery (BL3819)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.8V, 1800mAh Li-Polymer replacement battery for the Fly IQ4514 and IQ4514 Quad EVO Tech 4 smartphones. It replaces OEM part number BL3819. Use this when the original cell no longer holds charge or the phone shuts down unexpectedly under load.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eIQ4514 and IQ4514 Quad EVO Tech 4 compatibility:\u003c\/strong\u003e\n    Both variants use the same BL3819 cell format — identical voltage rail, connector pinout, and BMS handshake. One replacement covers both 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 charge and discharge on the IQ4514 platform. The BMS accepted the charge IC handshake on the first cycle and held voltage within spec under simultaneous screen-on and modem load.\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 complete discharge-to-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on 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 IQ4514 after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the fuel gauge IC is still referencing the discharge curve of the old, degraded cell. The new cell has a steeper voltage drop near the lower end of its curve than the worn cell did. When the modem fires during a call or data transfer, voltage sags below the shutdown threshold before the gauge reads zero. The fix is one full discharge cycle with the screen on — let it run until the phone powers off on its own, then charge to 100% uninterrupted. After that cycle, the coulomb counter recalibrates to the new cell and percentage readings stabilise.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone will not power on after the BL3819 sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-Polymer cells self-discharge over time. If the cell dropped below roughly 2.5V per cell during storage, the BMS enters lockout mode and blocks all charge current to prevent thermal runaway on a deeply discharged cell. Connect the phone to a wall charger — not a USB port — and leave it for 20–30 minutes without pressing the power button. The charge IC trickle-charges the cell at a low current rate to bring it back above the BMS recovery threshold, typically around 3.0V, at which point normal charging resumes and the phone boots.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392097222746,"sku":"BWCS-FIQ451SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392097255514,"sku":"BWCS-FIQ451SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392097288282,"sku":"BWCS-FIQ451SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FIQ451SL-1.webp?v=1779143748","url":"https:\/\/batteryweb.com\/products\/fly-iq4514-replacement-battery-38v-1800mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}