Apple iPhone 6 Compatible Battery 3.82V 1800mAh 616-0805

Apple iPhone 6 — 3.82V Li-Polymer Replacement Battery (616-0805)

This 3.82V, 1800mAh Li-Polymer battery replaces the original cell in the Apple iPhone 6, covering models A1586, A1589, and A1549. It fits the same physical envelope — 96.17 × 37.60 × 3.20mm — and connects to the same logic board connector as the factory unit. Capacity is rated at 6.88Wh, matching the original specification.

• A1586, A1589, A1549 compatibility: These three model numbers share the same battery bay dimensions, connector pinout, and BMS handshake protocol. One cell covers all three variants without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on an iPhone 6 logic board. The BMS accepted the cell, charge IC engaged correctly, and the fuel gauge IC registered the new capacity without triggering a fault state.
• Fuel gauge recalibration after installation: On first use, disable any fast-charge accessories and run one full discharge down to automatic shutdown, then charge uninterrupted to 100%. This gives the coulomb counter a clean reference cycle against the new cell's discharge curve before high-current charging begins.

Sudden shutdown at 20–30% on the iPhone 6 after a cell swap

The iPhone 6 fuel gauge IC holds a discharge curve model built from hundreds of cycles on the old, degraded cell. When a new cell arrives, its internal resistance is lower and its voltage cliff sits at a different point. The fuel gauge predicts shutdown too late, so the phone cuts power while the reported percentage still reads 20–30%. This is not a fault in the replacement cell — it is a calibration mismatch. Run one full discharge to automatic shutdown followed by a full uninterrupted charge to 100%, and the coulomb counter will rebuild its model against the new cell's actual curve.

iPhone 6 not powering on after the replacement cell sat in storage

Li-Polymer cells self-discharge during storage. If this battery has been sitting in a warehouse or drawer, its resting voltage may have dropped below 2.5V per cell — the threshold at which the BMS locks out to prevent damage. The phone will show no response to the power button and no charge indicator on the screen. Connect a known-good Lightning cable and leave it on charge for 15–20 minutes before attempting to power on; the charge IC will trickle current into the cell until the BMS releases its lockout, typically above 2.8V.