About this replacement
Medion Akoya E6416 Series — 15.2V Li-ion Replacement Battery (A41-D15)
This is a 15.2V Li-ion battery rated at 2600mAh (39.52Wh), built to fit the Medion Akoya E6416 and related E6400-series notebooks. OEM part numbers A41-D15, A31-D15, A32-D15, and A42-D15 all cross to this cell. Confirmed fit also covers the Akoya E6422, E6415, and E6411.
- Akoya E6400-series compatibility: These models share the same 15.2V four-cell Li-ion architecture, connector pinout, and BMS handshake protocol. One cell covers the entire platform without any modification.
- Bench tested on actual hardware: We cycled this cell on an E6416 unit. The BMS negotiated correctly with the BIOS on first boot, charge current ramped as expected, and the protection circuit triggered cleanly at low-voltage cutoff.
- Post-install calibration on Akoya notebooks: After fitting this cell, run the laptop down fully until it hibernates, then charge uninterrupted to 100% without using the machine. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity, clearing the inaccurate health warning that appears after every cell swap.
Why the Akoya E6416 BIOS reports poor battery health right after a new cell install
The BIOS stores the previous battery's EEPROM data — cycle count, state-of-health, and rated capacity — and compares it against the new cell on every boot. A fresh cell with zero cycles reads as mismatched against that stored profile, so the BIOS flags it as degraded. This is a firmware interpretation issue, not a fault with the replacement cell. One full discharge-to-hibernate followed by an uninterrupted charge to 100% rewrites the learn cycle data and clears the warning. After two or three full cycles the health indicator will reflect the actual state of the new cell.
Akoya E6416 shutting down unexpectedly while the gauge still shows 20–30% charge
This happens when the fuel gauge IC has not yet calibrated against the new cell's discharge curve. The IC is still using voltage-to-capacity mapping from the old, degraded cell, so it misreads the remaining charge. Under full CPU and display load the new cell hits a voltage cliff the old map did not predict, and the BIOS cuts power before the gauge reaches zero. Run two complete discharge-to-hibernate and full-recharge cycles without interrupting the charge. By the second cycle the fuel gauge IC recalibrates its curve, and the reported percentage will align with actual cell voltage — typically stabilising above 3.2V per cell at the 15% mark.