Apple MacBook Pro 15" A1398 Replacement Battery 11.36V 8700mAh

Apple MacBook Pro 15" A1398 Retina 2015 — 11.36V Li-Polymer Replacement Battery (A1618)

This is an 11.36V, 8700mAh (98.83Wh) Li-Polymer battery for the MacBook Pro 15-inch A1398 Retina, 2015 model. It fits machines running the MJLQ2LL/A and MJLT2LL/A configurations, as well as the Chinese-market MJLQ2CH/A and MJLT2CH/A variants. It also covers select 2013 A1398 Retina builds that share the same battery bay and connector spec.

• A1398 Retina compatibility across model years: Apple used the A1618 cell across multiple A1398 production runs because the battery bay dimensions, connector pinout, and BMS handshake protocol stayed consistent from late 2013 through mid-2015. Voltage rail and SMBus communication remained unchanged across those configurations.
• Bench tested on actual hardware: We ran this cell on a 2015 A1398 unit. The SMC recognised the battery immediately, the BMS negotiated charge current without fault, and the fuel gauge IC began tracking cell state from the first cycle.
• First-cycle conditioning on macOS: After installation, run the machine on battery until macOS initiates safe sleep at low charge, then charge uninterrupted to 100%. This resets the SMC battery learn cycle and clears the inaccurate health warning that appears in System Information after a cell swap.

Why macOS reports poor battery health immediately after swapping the A1618

The MacBook Pro's SMC stores cycle count, full-charge capacity, and health data in EEPROM tied to the old cell. When a new cell installs, that stored data mismatches the new cell's reported values, so macOS flags health as degraded or shows an unexpected wattage in System Report. This is a data mismatch, not a cell fault. Running one full discharge-to-sleep cycle followed by an uninterrupted charge to 100% forces the SMC to rewrite its battery learn table against the new cell. After two to three cycles, System Information should report normal condition and a full-charge capacity close to 98.83Wh.

MacBook Pro A1398 shutting down at 20–30% charge shown on the menu bar

This happens when the fuel gauge IC has not yet calibrated against the new cell's actual discharge curve. The IC uses the old cell's voltage-to-capacity mapping, so it miscalculates the remaining charge and triggers an SMC shutdown well before the cell is actually depleted. The fix is a full calibration cycle: discharge to forced sleep, then charge to 100% without interruption. Repeat twice if the cutoff persists — after two complete cycles the fuel gauge IC recalibrates its curve and the reported percentage aligns with actual cell voltage, typically holding stable above 10.8V at shutdown.