Mechrevo Z2 Air 15.2V Laptop Replacement Battery 4000mAh

Mechrevo Z2 Air / Z2 / Z3 / Z3 Pro — 15.2V Li-Polymer Replacement Battery

This is a 15.2V, 4000mAh (60.8Wh) lithium-polymer replacement battery for the Mechrevo Z2 Air, Z2, Z3, and Z3 Pro laptops. It slots into the original battery bay and connects via the factory harness. Capacity figures come from the product specification — not estimated from third-party sources.

• Z2 Air, Z2, Z3, and Z3 Pro compatibility: These four models share the same 15.2V battery rail, connector pinout, and BMS handshake protocol. A single cell revision covers all four without modification or adapter.
• Bench tested on actual hardware: We ran charge and discharge cycles on this cell and monitored BMS communication. The protection circuit held cutoff voltage correctly and reported state-of-charge accurately after calibration cycles were completed.
• BIOS learn cycle after swap: After fitting this cell, run the laptop down to hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell replacement on this platform.

BIOS reporting poor battery health immediately after installation

The Mechrevo BIOS reads EEPROM data written during the previous cell's life. When a new cell is installed, that stored data no longer matches the actual cell state. The BIOS interprets the mismatch as degradation and flags health as poor or unknown. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% forces the firmware to rewrite that EEPROM data against the new cell. After two to three full cycles, the health report corrects itself.

Laptop shuts down at 20–30% charge shown on the gauge

This happens when the fuel gauge IC has not yet calibrated against the new cell chemistry. The displayed percentage is based on stale capacity data from the old cell, so the system cuts power well before 0% is reached. It is not a fault with the replacement cell. Run two to three full discharge-to-hibernate and uninterrupted recharge cycles — by the third cycle the gauge IC recalculates capacity from real measurements and the shutdown at 20–30% stops. Check that cell voltage at the reported 20% mark is above 14.0V to confirm calibration is progressing correctly.