About this replacement
Lenovo IdeaPad Flex 4-1480 — 11.4V Li-Polymer Replacement Battery (L15C3PB1)
This is an 11.4V, 4550mAh lithium-polymer replacement battery for the Lenovo IdeaPad Flex 4-1480, Flex 4-1480 14", Flex 4-1570, and Flex 4-1580 80VE series. It replaces OEM part numbers L15C3PB1, B102297-0004, 5B10K84638, and L15M3PB0. Swap it in when the original cell no longer holds charge or causes unexpected shutdowns.
- Flex 4-1480 / 4-1570 / 4-1580 series compatibility: These models share the same 11.4V three-cell battery rail, identical connector pinout, and the same BMS handshake protocol — one cell fits the full platform without modification.
- Bench tested on actual hardware: We ran this cell on a Flex 4-1480 unit and confirmed the BMS negotiated correctly with the BIOS on first boot. The fuel gauge IC picked up the cell and charge cycling began without error flags.
- Post-install calibration on the Flex 4: After fitting this battery, run the unit 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 swapping cells on Lenovo IdeaPad hardware.
BIOS reporting poor battery health immediately after fitting a new cell
The Lenovo BIOS reads health data stored in the battery's EEPROM, not from live cell chemistry. When a new cell is installed, the EEPROM data doesn't match the BIOS's learned discharge profile from the old battery. The system flags this as degraded health even though the cell is new. One full discharge-to-hibernate followed by an uninterrupted charge to 100% rewrites the learn cycle and clears the warning.
Flex 4 shutting down at 20–30% charge shown on screen
This happens when the cell voltage drops sharply under combined CPU and display load before the fuel gauge reaches zero — a voltage cliff caused by a worn or mismatched cell. The OS fuel gauge reads state-of-charge against a discharge curve that no longer matches the cell's actual output. A new cell with the correct chemistry resets the discharge curve the fuel gauge IC tracks against. After two full calibration cycles, shutdowns at 20–30% shown should stop.