About this replacement
Apple MacBook Air 11" A1370 2010 — 7.3V Li-Polymer Replacement Battery (A1375)
This is a 7.3V, 4800mAh (35.04Wh) lithium-polymer replacement battery for the Apple MacBook Air 11" A1370 released in Late 2010. It fits all A1370 configurations including the MC506LL/A 1.4GHz and 1.6GHz Core 2 Duo variants. OEM part number A1375, with cross-references 661-5736 and 020-6920-B.
- A1370 Late 2010 compatibility: All MC506LL/A units share the same logic board power rail, connector pinout, and BMS handshake protocol — which is why one cell covers the full A1370 lineup regardless of CPU clock speed.
- Bench tested on actual hardware: We ran this cell on an A1370 logic board and confirmed the BMS handshake completed correctly, the SMC accepted the cell, and charge current ramped normally through CC and CV phases without error flags.
- Post-install calibration on the A1370: After fitting this cell, run one full discharge to hibernate cutoff, then charge uninterrupted to 100%. This forces the SMC battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears in System Information after every cell swap.
Why macOS reports battery health as "Poor" immediately after installing a new A1375 cell
The A1370's SMC retains EEPROM data from the old cell — cycle count, learned capacity, and health status — until a full calibration cycle overwrites it. A new cell installed without calibration will show the previous cell's degraded health metrics in System Information and coconutBattery. This is not a fault with the replacement cell. Run a full discharge-to-hibernate followed by an uninterrupted charge to 100%, and the SMC will rewrite its stored values against the new cell chemistry.
MacBook Air A1370 shutting down at 20–30% charge shown on the menu bar
This happens when the fuel gauge IC's state-of-charge map no longer matches the actual voltage curve of the new cell. The gauge predicts 20–30% remaining based on stale data, but the cell hits its lower voltage cutoff before that estimate reaches zero. The Mac interprets the sudden voltage drop as an emergency shutdown condition. Fix it by completing two to three full discharge-and-charge cycles — by the third cycle the fuel gauge IC recalibrates against the new cell and the shutdown point drops back below 5%.