About this replacement
Apple iPhone Xs — 3.8V Li-Polymer Replacement Battery (616-00514)
This is a 3.8V, 2600mAh lithium-polymer replacement battery for the Apple iPhone Xs, covering model numbers A1920, A2097, and related variants. It slots into the same physical bay as the original cell and connects to the same flex cable assembly. Voltage and capacity match the OEM specification exactly.
- iPhone Xs / A1920 / A2097 compatibility: These models share the same 3.8V power rail, identical connector pinout, and the same fuel gauge IC handshake protocol. Any cell going into this bay must match those parameters — this one does.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on an iPhone Xs board. The BMS accepted the cell without fault flags, and the charge IC stepped through trickle, CC, and CV phases correctly with no thermal interruptions.
- Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging for one complete discharge-to-charge cycle. This lets the fuel gauge IC map its coulomb counter to the new cell's actual discharge curve before high-current charging is applied to an uncalibrated cell.
Why the iPhone Xs reports wrong battery percentage after a cell swap
The iPhone Xs uses a coulomb-counter-based fuel gauge IC that builds its percentage model from the previous cell's charge history. After a cell swap, that stored model no longer matches the new cell's actual capacity and impedance curve. Until the IC runs at least one full discharge from 100% to automatic shutoff and back to full charge, the percentage readout will drift or read high. One full unconstrained cycle resets the reference baseline and the reported percentage stabilises.
Sudden shutdown at 20–30% charge on the replacement cell
This happens when the fuel gauge IC is still calibrated to the old cell's voltage curve and misjudges the remaining usable capacity. Under modem load or screen brightness spikes, the new cell's terminal voltage drops faster than the IC expects, triggering an emergency cutoff before the displayed percentage reaches zero. It is not a fault with the cell itself. Run one full discharge cycle without fast charging — once the IC re-maps the voltage cliff of the new cell, shutdowns at 20–30% stop.