About this replacement
Lenovo IdeaPad Y700 / Eraser Y700 Series — 14.8V Li-Polymer Replacement Battery (L14S4P22)
This 14.8V, 4000mAh (59.2Wh) Li-Polymer battery replaces the original cell in the Lenovo IdeaPad Y700, IdeaPad Y700 Touch, Eraser Y700, and Eraser Y700 Touch. It covers OEM part numbers L14S4P22, L14L4P23, L14M4P23, 5B10H22084, and 5B10H22085. The connector, BMS handshake protocol, and cell voltage match the factory specification.
- Y700 and Eraser Y700 platform fit: Both the standard and Touch variants of the IdeaPad Y700 and Eraser Y700 use the same 14.8V four-cell pack configuration, shared BMS authentication logic, and identical physical connector — which is why a single part number covers the full lineup.
- Bench tested on actual hardware: We ran this cell through charge and discharge on a Y700 chassis. The BMS handshook cleanly on first connection, charge acceptance started immediately, and the protection circuit triggered correctly at low-cell cutoff without forcing a hard shutdown.
- Post-install calibration cycle: After fitting, run the laptop down to hibernate cutoff under normal use, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after installation
Lenovo's BIOS reads EEPROM data written by the original cell and compares it against current charge state. A new cell has no accumulated cycle data, so the firmware flags it as degraded or unknown. This is a firmware interpretation issue, not a cell fault. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% writes fresh calibration data and clears the warning. After two or three cycles the health status normalises.
Laptop shuts down at 20–30% charge shown on screen
This happens when the fuel gauge IC is still calibrated to the old cell's voltage curve. Under full CPU and display load the new cell's actual voltage drops faster than the IC predicts, and the system hits the BMS low-voltage cutoff before the OS gauge reaches zero. The gauge reports 20–30% while the real cell voltage is already at the protection floor — around 11.0V for a four-cell 14.8V pack. Run two full calibration cycles and the fuel gauge IC maps correctly to the new cell's discharge curve.