About this replacement
Apple MacBook Pro 14 2021 — 11.47V Li-Polymer Replacement Battery (A2519)
This is an 11.47V, 6050mAh (69.39Wh) lithium-polymer battery for the Apple MacBook Pro 14 2021. It fits models A2442, EMC3650, and MKGR3LL/A, among others. Direct swap for a degraded or failed A2519 cell.
- MacBook Pro 14 2021 compatibility: All listed A2442 variants share the same three-cell Li-Polymer stack, 11.47V rail, and SMC power handshake. The connector pinout and BMS communication protocol are identical across the EMC3650 production run, so one cell fits the full range.
- Bench tested on actual hardware: We cycled this cell through charge, discharge, and SMC handshake verification on a MacBook Pro 14 2021 unit. The BMS reported correct voltage and capacity data, and the SMC accepted the cell without triggering a service warning on first boot.
- Post-install calibration on macOS: After fitting this cell, run one full discharge until the laptop hibernates on its own, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.
macOS reporting battery health as "Poor" immediately after replacement
The SMC and macOS System Information pull health data from EEPROM stored on the old battery's BMS. When a new cell lands in the same slot, the fuel gauge IC has no learned data to work from, so macOS flags the health state as unknown or poor. This is not a cell fault. Run two full discharge-to-hibernate and charge-to-100% cycles. After both cycles, the fuel gauge IC recalibrates against the new cell chemistry and macOS will report accurate health.
MacBook Pro shuts down at 20–30% charge shown on screen
This happens when the fuel gauge IC's state-of-charge map no longer matches the new cell's actual voltage curve. Under combined CPU and display load, the cell hits a voltage cliff that the uncalibrated gauge did not predict, and the SMC triggers an emergency shutdown. The percentage reading on screen is wrong — the cell still has charge but the system cannot see it accurately. Discharge fully to hibernate, then charge to 100% without interruption, and repeat once more to align the gauge to the new cell's discharge profile.