About this replacement
Apple MacBook Air 13 (A1965) — 11.4V Li-Polymer Replacement Battery
This is an 11.4V, 4800mAh (54.72Wh) Li-Polymer battery for the Apple MacBook Air 13-inch. It fits models including MREE2CH/A, MRE92CH/A, MREC2CH/A, and MRE82CH/A, among others. OEM part numbers covered include A1965, 020-02459, 020-02455, and 661-11676.
- MacBook Air 13 mid-2018 and 2019 compatibility: These models share a common 11.4V three-cell Li-Polymer architecture, identical connector pinout, and the same SMC battery handshake protocol — which is why a single cell works across all variants in this generation.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on MacBook Air 13 hardware. The SMC recognised the battery, accepted a charge from 0V, and BMS protections tripped correctly at the expected low-voltage cutoff threshold.
- SMC learn cycle after install: After fitting this cell, run the machine down until it hibernates on its own, then charge uninterrupted to 100% without use. This resets the SMC battery learn cycle and clears the inaccurate health or low-capacity warning macOS shows after any cell swap.
Why macOS reports poor battery health immediately after swapping the A1965 cell
The MacBook Air's SMC stores charge history and cycle count data tied to the previous cell's EEPROM profile. When a new cell goes in, the SMC reads a mismatch between its stored data and the new cell's reported state, flagging health as degraded or unknown. This is not a fault with the replacement cell — it is the SMC reacting to unfamiliar EEPROM data. Running one full discharge-to-hibernate followed by a full uninterrupted charge gives the SMC enough data to re-baseline its fuel gauge against the new cell.
MacBook Air shutting down at 20–30% charge remaining
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The SMC shuts the system down the moment cell voltage drops below its safety threshold — even if the displayed percentage still reads high. Under combined CPU and display load, voltage sag can hit that cutoff faster than the gauge expects on an uncalibrated cell. Run two full discharge-to-hibernate and full-charge cycles to let the fuel gauge IC map the new cell's real voltage cliff, and the shutdowns will stop.