Medion Erazer X6805 Compatible Battery 11.4V 4000mAh 40068133

Medion Erazer X6805-MD61085 — 11.4V Li-Polymer Replacement Battery (40068133)

This 11.4V, 4000mAh (45.6Wh) lithium-polymer cell replaces the original battery in the Medion Erazer X6805-MD61085 gaming laptop and fits the broader Erazer X6805, X6807, and X15807 series. It matches the OEM part number 40068133 and the MSN references 30027092 and 30027408. Swap it in when the original cell no longer holds charge or the BIOS flags poor battery health.

• Erazer X6805 and X6807 series compatibility: These models share the same 11.4V three-cell Li-Polymer architecture, identical connector pinout, and the same BMS handshake protocol — so one cell covers the entire platform without firmware conflicts.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the Erazer X6805 platform. The BMS completed its handshake cleanly, charge current tapered correctly at top-of-charge, and the protection circuit responded to over-discharge cutoff at the expected voltage floor.
• BIOS learn cycle after installation: After fitting this cell, run the laptop down to hibernate cutoff on battery power alone — no AC — then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on Erazer hardware.

Erazer X6805 shutting down at 20–30% shown on the gauge

Under sustained gaming load — full CPU boost plus discrete GPU plus a bright display — the Erazer X6805 pulls significantly more current than the fuel gauge IC accounts for at rest. When a new cell's internal resistance differs from the original, the voltage drops sharply under that combined load before the displayed percentage reflects it. The BIOS reads a voltage cliff and triggers a hard shutdown to protect the cell, even though the gauge still shows charge remaining. Run two full discharge-to-hibernate cycles to let the fuel gauge IC recalibrate against the new cell's actual voltage curve.

BIOS reporting wrong Wh rating after replacement

The system info screen reads Wh data from the EEPROM embedded in the battery's BMS — not from live measurement. If the value shown differs from the rated 45.6Wh, the EEPROM on the new cell is reporting its design-rated chemistry figure, which may differ slightly from the outgoing cell's stored value. This does not affect charging behaviour or actual capacity delivered. Confirm the physical voltage under charge reads 11.4V at nominal and up to 12.6V at full charge — if both check out, the Wh display discrepancy is cosmetic only.