About this replacement
Apple iPhone XR — 3.8V Li-Polymer Replacement Battery (616-00471)
This 3.8V, 3500mAh Li-Polymer battery replaces the original cell in the Apple iPhone XR, covering models A2105, A2106, A2108, and two additional regional variants. It matches the OEM dimensions at 101.00 × 44.65 × 4.25mm, fitting the factory tray without modification. Voltage and capacity match Apple's specification for this model line exactly.
- iPhone XR and A21xx variants: All five model numbers in this family share the same battery bay geometry, flex connector pinout, and BMS handshake protocol. One cell covers the full regional lineup without adapter or modification.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on an iPhone XR unit, confirming the BMS accepted the cell, charge termination triggered correctly at 4.35V, and the fuel gauge IC initialised without error flags.
- First-cycle fuel gauge recalibration: After installation, disable fast charging and run one complete discharge-to-charge cycle at standard 5W. The fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve — skipping this step can leave the percentage readout several points off until the IC self-corrects.
Sudden shutdown at 20–30% on the iPhone XR after a cell swap
This happens because the fuel gauge IC is still using the discharge curve it mapped to the old, degraded cell. The new cell has a steeper voltage cliff at low state-of-charge, and the IC misjudges remaining capacity. Under modem or display load, the cell voltage drops faster than the IC expects, triggering an emergency shutdown before the displayed percentage reaches zero. One full discharge-to-shutdown followed by a complete charge cycle lets the coulomb counter remap to the new cell curve — after that cycle, shutdowns at 20–30% stop.
iPhone XR reporting wrong battery percentage after replacement
The fuel gauge IC stores a learned discharge profile for the cell it has been tracking — replace the cell and the stored profile no longer matches the new chemistry curve. The result is percentage jumps, readings that stick at one number for too long, or a sudden drop of 10–15 points under load. Force a full recalibration: drain the phone until it powers off on its own, then charge uninterrupted to 100% without removing the cable. After one complete cycle the IC overwrites its stored curve with data from the new cell and percentage accuracy stabilises.