Cjscope MX-756 Laptop Compatible Battery 11.1V 5400mAh

Cjscope MX-756 — 11.1V Li-ion Replacement Battery

This is an 11.1V, 5400mAh (59.94Wh) lithium-ion battery for the Cjscope MX-756 notebook. It replaces a dead or degraded original cell and restores untethered operation. Fit is direct — same voltage, same form factor, same connector orientation as the factory unit.

• MX-756 compatibility: The MX-756 uses an 11.1V three-cell series pack with a specific BMS handshake tied to that voltage rail. This replacement matches that rail exactly, so the system board recognises the pack without throwing a "battery not detected" POST error.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a notebook platform at the same voltage class. The BMS held cutoff correctly at both ends — no overcharge trip, no premature low-voltage disconnect under display-plus-CPU load.
• First-cycle calibration on the MX-756: After fitting, run one full discharge to hibernate cutoff, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity and clears the inaccurate health warning that appears after every cell swap on this platform.

BIOS reporting battery health as poor after replacement

When a new cell goes in, the BIOS still holds EEPROM data from the old pack. It compares the new cell's charge state against stale cycle-count and capacity records, so it flags the battery as degraded even though the cell is fresh. This is not a fault with the replacement — it is a firmware calibration issue. Run the full discharge-to-hibernate then uninterrupted charge cycle described above. After one or two complete cycles, the BIOS recalibrates and the health warning clears.

Laptop shutting down at 20–30% remaining after battery swap

This happens when the fuel gauge IC has not yet mapped the new cell's voltage curve. The OS reads a percentage based on the old cell's discharge profile, so the reported figure and actual cell voltage fall out of sync. Under full CPU and display load, the cell hits its real low-voltage floor before the OS expects it, and the system cuts power abruptly. Run two full calibration cycles — discharge to hibernate, charge to 100% — to let the fuel gauge IC build an accurate map against the new cell. After calibration, the shutdown threshold should align with the displayed percentage at or below 10%.