Lenovo ThinkPad S230u 45N1092 14.8V Compatible Battery

Lenovo ThinkPad S230u — 14.8V Li-Polymer Replacement Battery (45N1092)

This 14.8V, 2800mAh (41.44Wh) lithium-polymer cell replaces the original battery in the Lenovo ThinkPad S230u convertible ultrabook. It fits the ThinkPad S230u, ThinkPad Edge S230u, ThinkPad Twist S230u, and ThinkPad S230u Twist (3347-25C), along with over 36 additional compatible configurations. OEM part numbers covered: 45N1092, 45N1093, 45N1094, and 45N1095.

• S230u and Twist variant compatibility: All S230u configurations share the same 14.8V four-cell Li-Polymer architecture, identical connector pinout, and the same BMS handshake protocol. That is why one cell covers the standard, Edge, and Twist variants without modification.
• Bench tested on actual hardware: We cycled this cell on a ThinkPad S230u under mixed CPU and display load. The BMS communicated correctly with the BIOS on first insertion, charge acceptance began immediately, and the protection circuit held within the expected cutoff thresholds throughout full charge and discharge cycles.
• Post-install calibration on the S230u: After fitting this cell, run one full discharge until the laptop hibernates on its own, then charge uninterrupted to 100% without interruption. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears in Lenovo Vantage after every cell swap.

BIOS reporting poor battery health immediately after replacement

The ThinkPad BIOS stores learned capacity data in EEPROM tied to the original cell. When a new cell is installed, the BIOS compares live readings against that old dataset and flags a health mismatch — this is not a fault with the replacement battery. The fix is a full discharge-to-hibernate followed by an uninterrupted charge to 100%, which overwrites the EEPROM baseline with values from the new cell. After one or two complete cycles, Lenovo Vantage and the BIOS health indicator return to normal. No firmware update or BIOS reset is needed.

Laptop shutting down at 20–30% charge shown on screen

This happens when the fuel gauge IC still holds calibration data from the degraded original cell. Under full CPU plus display load, the new cell's actual voltage profile doesn't match the old discharge curve stored in the gauge — the system hits what looks like a voltage cliff and shuts down before the display reaches 0%. It is a calibration lag, not a capacity defect. Run two full discharge-to-hibernate and charge-to-100% cycles back to back, and the fuel gauge IC recalibrates against the new cell's actual voltage curve. After those two cycles, the reported percentage and the actual shutdown point align correctly.