Lenovo B465 Replacement Battery 11.1V 4400mAh 3ICR19/66-2

Lenovo B465 Series — 11.1V Li-ion Replacement Battery (3ICR19/66-2)

This is an 11.1V, 4400mAh (48.84Wh) Li-ion replacement battery for the Lenovo IdeaPad B465 notebook. It fits the B465, B465A, B465C, and B465G, among other models in the series. Install it when the original cell no longer holds a usable charge or the OS reports capacity as critically degraded.

• B465 series compatibility: The B465 family shares a common 11.1V three-cell battery bay and identical connector pinout across the A, C, and G sub-variants. The BMS handshake uses the same EEPROM protocol on all of them, so one cell fits the entire lineup without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a B465 unit and confirmed the BMS accepted the new cell, balanced across all three groups, and reported capacity correctly in Lenovo Vantage after the learn cycle completed.
• Post-install calibration on B465: After fitting this battery, run one full discharge until the laptop hibernates on its own, then charge uninterrupted to 100% without using the machine. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears immediately after every cell swap on this platform.

BIOS reporting poor battery health immediately after fitting a new cell

The B465 BIOS reads health data from the battery's EEPROM, which stores cycle count and rated capacity from the previous cell. When a new cell is installed, that EEPROM data doesn't automatically reset, so the BIOS flags the battery as degraded even though the new cell is at full capacity. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% triggers the learn cycle and rewrites the BIOS health register. After that cycle, Lenovo Vantage and the Windows power report should reflect the correct 48.84Wh rating.

Laptop shuts down at 20–30% charge shown on the B465

This happens when the fuel gauge IC hasn't yet calibrated against the new cell's actual voltage curve. The gauge maps the old cell's discharge profile onto the new one, so the percentage reading drifts and the laptop hits a voltage cliff before the displayed number reaches zero. The fix is two or three full discharge-to-hibernate and uninterrupted-recharge cycles, which let the fuel gauge IC relearn the new cell's curve. After calibration, the shutdown threshold should align with the actual cell voltage at cutoff, typically around 9.0V under load.