About this replacement
Apple MacBook Pro EMC 3301 — 11.41V Li-Polymer Replacement Battery (A2171 / 616-00675)
This is a 11.41V, 5100mAh (58.19Wh) lithium-polymer battery for the Apple MacBook Pro EMC 3301 13-inch. It fits models MUHN2LL/A, MUHP2LL/A, and MUHQ2LL/A, among others. The OEM part numbers are A2171 and 616-00675.
- EMC 3301 compatibility: These MacBook Pro 13-inch units from 2019 share a single battery form factor across the Touch Bar and non-Touch Bar variants. The connector, BMS handshake protocol, and cell dimensions are identical across that lineup — one cell fits all covered models.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a MacBook Pro EMC 3301 unit. The BMS negotiated correctly with the SMC, charge acceptance was clean from 0% to 100%, and no thermal or voltage faults were flagged during the session.
- SMC calibration after install: After fitting this battery, let the laptop discharge completely until it sleeps, then charge uninterrupted to 100% without waking the machine mid-cycle. This gives the System Management Controller a clean baseline against the new cell and clears the false "Service Battery" warning that often appears after a swap.
macOS reporting poor battery health immediately after replacement
The health status in macOS reads from EEPROM data held by the battery's BMS — not from live cell measurements. When a new cell goes in, that EEPROM carries factory-default cycle and capacity values that the SMC hasn't yet validated against real-world charge data. macOS flags this mismatch as degraded health. One full discharge-to-sleep followed by an uninterrupted charge to 100% triggers the SMC battery learn cycle, which rewrites the health estimate against actual cell behaviour. After one or two cycles the health indicator typically updates to Normal.
MacBook Pro shutting down at 20–30% charge shown on screen
This happens when a cell can't hold voltage above the SMC's cutoff threshold under combined CPU and display load — even though the fuel gauge still shows charge remaining. The fuel gauge IC is reading stored charge, but the cell voltage collapses faster than the gauge tracks under load. The fix is a full calibration cycle: run the laptop under normal workload until it shuts itself off, then charge to 100% in one session. After two to three calibration cycles, the fuel gauge IC maps the new cell's actual voltage curve and the premature shutdowns stop.