About this replacement
Apple iPhone 6 / A1586 / A1549 — 3.82V Li-Polymer Replacement Battery (616-0805)
This 3.82V, 2160mAh Li-Polymer battery replaces the original cell in the Apple iPhone 6, covering model numbers A1586, A1589, and A1549. It matches the OEM part numbers 616-0804, 616-0805, 616-0806, and 616-0809. At 96.90 × 39.00 × 3.50mm, it fits the original battery bay without modification.
- iPhone 6 model coverage: The A1586, A1549, and A1589 variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers all three without adapter or wiring change.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on an iPhone 6 A1586. The BMS communicated correctly with the charge IC, held voltage through screen-on and modem-active load, and passed Apple's battery health check in Settings.
- Fuel gauge recalibration on first use: After installation, disable fast charging for the first complete discharge-charge cycle. The fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve — skipping this can leave the IC reading the old curve and reporting inaccurate percentages for several days.
Sudden shutdown at 20–30% on the iPhone 6 after a cell swap
The iPhone 6's fuel gauge IC stores a charge curve from the previous cell in non-volatile memory. When a new cell goes in, the stored curve no longer matches the actual discharge profile of the replacement. Under high-current loads — active LTE, screen at full brightness, GPS — the cell voltage dips faster than the IC expects, triggering a protection cutoff before the displayed percentage reaches zero. One full discharge-charge cycle forces the coulomb counter to rebuild its curve against the new cell. After that cycle, the 20–30% shutdowns stop.
iPhone 6 not powering on after the battery sat discharged in storage
Li-Polymer cells enter BMS lockout when voltage drops below approximately 2.5V per cell — a state triggered by extended storage in a discharged condition. In lockout, the phone shows nothing on screen and does not respond to the power button. Connect the phone to a wall adapter rated at 5V/1A and leave it for 20–30 minutes without pressing any button — the charge IC trickle-charges the cell back above the BMS re-enable threshold. Once the Apple logo appears, the BMS has released lockout and normal charging resumes.