Apple iPad 2 Replacement Battery 616-0561 3.7V 6300mAh

Apple iPad 2 / iPad 2 3G / iPad 2 Wi-Fi — 3.7V Li-Polymer Replacement Battery (616-0561)

This is a 3.7V, 6300mAh lithium-polymer battery for the Apple iPad 2 lineup, including the Wi-Fi and 3G variants. It fits models referencing OEM part numbers 616-0561 and 616-0559. If your iPad 2 no longer holds a charge, drains rapidly, or won't power on, this is the cell that replaces the original.

• iPad 2 Wi-Fi and 3G compatibility: The Wi-Fi and 3G variants of the iPad 2 share the same battery footprint, voltage rail, and connector pinout. Both pull from the same charge IC and use the same BMS communication protocol, so one cell covers all three sub-models without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an iPad 2 board. The BMS accepted the new cell without triggering protection cutoff, and the charge IC ramped correctly from trickle to CC/CV phases at 3.7V nominal.
• Fuel gauge reset after installation: After fitting this cell, run the iPad down to automatic shutoff, then charge it uninterrupted to 100%. This single full cycle recalibrates the fuel gauge IC against the new cell's actual capacity curve and corrects the inaccurate percentage readings that appear immediately after a swap.

iPad 2 shutting down at 15–25% remaining after a battery swap

When the display backlight and Wi-Fi radio draw current simultaneously, voltage sags faster than the fuel gauge expects — especially on a freshly fitted cell the IC hasn't mapped yet. The system interprets the voltage drop as a critically low state-of-charge and forces a shutdown, even though capacity remains. The fix is a full discharge-to-shutoff followed by an uninterrupted charge to 100%, which gives the fuel gauge IC one complete reference cycle. After that calibration pass, the shutdown threshold tracks actual cell voltage accurately.

iPad 2 showing wrong battery percentage immediately after replacement

The iPad's fuel gauge IC stores a capacity model calibrated to the old, degraded cell. A new cell with a different discharge curve causes the IC to report percentage values that jump, stall, or read high when the device is actually low. This isn't a faulty battery — it's a calibration mismatch. Run one full cycle: discharge to automatic shutoff, then charge to 100% without interruption. The IC resets its model against the new cell and percentage reporting stabilises at around 4.2V full and 3.0V cutoff.