About this replacement
Dell Inspiron N311z / Vostro V131 Series — 11.1V Li-ion Replacement Battery (268X5)
This 11.1V, 4400mAh (48.84Wh) Li-ion battery replaces the original Dell 268X5 cell in the Inspiron N311z, Inspiron N411z, Vostro V131, and Vostro V131D. It fits the same battery bay and connects via the factory connector without modification. Capacity and voltage match OEM spec exactly.
- Shared platform — N311z, N411z, V131 series: These models share the same 11.1V three-cell battery bay, connector pinout, and BMS communication protocol. Dell used the same battery specification across both the Inspiron and Vostro lines built on this chassis, so one cell covers all listed models.
- Bench tested on actual hardware: We ran charge and discharge cycles on the N311z and Vostro V131. The BMS handshake completed without error, charge acceptance was full to 4400mAh, and the EC reported correct voltage throughout the discharge curve.
- BIOS learn cycle after install: 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 swap on Dell systems.
BIOS reporting battery health as poor after replacement
Dell's BIOS reads EEPROM data stored in the old cell and compares it against the new one. Until a full learn cycle runs, the embedded controller carries over the degraded health record from the previous battery. This triggers the "Consider replacing your battery" warning even with a brand-new cell installed. Run one full discharge to hibernate cutoff followed by an uninterrupted charge to 100% — the BIOS clears the warning after that cycle completes.
Laptop shuts down at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's discharge curve. The OS reads a voltage level that maps to 20–30% on the old cell's worn profile, but the actual cell voltage drops below the EC's cutoff threshold under CPU and display load. The result is an abrupt shutdown with charge percentage still showing on screen. Two to three full discharge-to-hibernate and full-charge cycles recalibrates the fuel gauge IC and brings the reported percentage back in line with actual cell voltage.