About this replacement
Lenovo E31-80 / IdeaPad 510S-13ISK — 7.6V Li-Polymer Replacement Battery (L14M2P24 / 5B10H13092)
This 7.6V 4550mAh Li-Polymer battery replaces the original cell in the Lenovo E31-80, U31-70, IdeaPad 510S-13ISK, and related 13-inch slim notebook models. It matches the OEM connector, BMS handshake profile, and flat-cell form factor used across this chassis family. Capacity is 4550mAh (34.58Wh) — identical to the factory specification.
- E31-80 and U31-70 chassis compatibility: These models share the same 7.6V two-cell Li-Polymer rail, identical 10-pin connector pinout, and the same BMS communication protocol — which is why one cell covers the full production run across both chassis variants.
- Bench tested on actual hardware: We ran this cell on an E31-80 unit and confirmed the BMS handshake completed without fault codes, charge acceptance cycled correctly through the CC/CV stages, and the fuel gauge IC registered the correct Wh rating by the second full cycle.
- Post-install discharge cycle on Lenovo slim notebooks: After fitting this cell, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity and clears the inaccurate health warning that appears on first boot after every cell swap.
Why Lenovo BIOS flags a new cell as "poor health" immediately after installation
The Lenovo BIOS reads battery health from EEPROM data written by the old cell during its lifetime. When a new cell is installed, the EEPROM cycle count and capacity history don't match the new cell's actual state — so the firmware flags it as degraded. This is a data mismatch, not a fault with the replacement cell. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% triggers the learn cycle that rewrites the BIOS health register against the new cell's real parameters. After two to three full cycles, the health indicator should update to reflect the actual cell condition.
Laptop shuts down at 20–30% remaining after the battery swap
This happens when the fuel gauge IC is still calibrated to the old cell's voltage curve. The IC predicts the cutoff point based on historical discharge data and calls empty too early once a new cell with a different voltage cliff is installed. Under combined CPU and display load, voltage sag accelerates the mismatch further — the system reads 25% but the IC triggers shutdown protection. Fix this by completing two full discharge-to-hibernate cycles with no interruption, then charging each time to exactly 100%. After two calibration cycles the fuel gauge re-anchors to the new cell's actual 3.0V per cell floor.