About this replacement
Lenovo IdeaPad 5 15 Series — 15.2V Li-Polymer Replacement Battery (L19C4PF1)
This is a 15.2V Li-Polymer battery rated at 4550mAh (69.16Wh), built as a direct cell replacement for the Lenovo IdeaPad 5 15 series. It fits the IdeaPad 5-15IIL05, IdeaPad 5-15ARE05, and Xiaoxin 15 2020 notebooks. OEM cross-references include 5B10W86940, 5B10W86948, L19L4PF1, L19M4PF1, SB10W86946, SB10W86949, and SB10W86960.
- IdeaPad 5 15 platform fitment: The IIL05 and ARE05 variants share the same 15.2V four-cell Li-Polymer architecture, connector pinout, and BMS handshake protocol — which is why one battery part number spans both Intel and AMD chassis generations.
- Bench tested on actual hardware: We ran this cell through charge, full-load discharge, and BMS communication checks on an IdeaPad 5-15IIL05. The BMS authenticated correctly, voltage held steady under combined CPU and display load, and charge termination triggered cleanly at capacity.
- BIOS learn cycle after install: After fitting this battery, run the laptop down to hibernate-cutoff under normal use, then charge uninterrupted to 100%. This forces the BIOS to recalibrate its battery learn cycle against the new cell and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after replacement
The IdeaPad 5 stores battery state data in EEPROM on the battery controller. When you swap the physical cell, the BIOS still reads the accumulated cycle count and degradation flags from the old EEPROM record until the learn cycle overwrites them. This is why Lenovo Vantage shows "poor" or "replace soon" even on a brand-new cell. One full discharge-to-hibernate followed by an uninterrupted charge to 100% resets the fuel gauge IC baseline. After two or three cycles the health indicator should read normal.
Laptop shuts down abruptly at 20–30% charge shown
This usually happens when the old cell has aged enough that it can no longer sustain voltage under combined CPU boost and display load — the actual cell voltage drops below the BMS cutoff threshold while the fuel gauge still reads 20–30%. The gauge was calibrated to a degraded cell, so the percentage shown no longer matches real capacity. With a new cell, run the BIOS learn cycle described above to force recalibration. If the shutdown persists after two calibration cycles, check that the battery connector is fully seated — an intermittent contact causes the same voltage cliff at load.