Lenovo ThinkPad Helix 2 Replacement Battery 7.4V 4800mAh

Lenovo ThinkPad Helix 2 — 7.4V Li-Polymer Replacement Battery (00HW010)

This 7.4V, 4800mAh (35.52Wh) Li-Polymer cell replaces the original battery in the Lenovo ThinkPad Helix 2 and related Helix detachable 2-in-1 models. It fits both the tablet unit and supports full portable operation once reseated and recognised by the BIOS. Part numbers 00HW010, SB10F46448, SB10F46442, 00HW004, and 00HW005 are all cross-compatible with this cell.

• Helix 2 tablet module compatibility: These Helix variants share the same 7.4V battery rail, connector pinout, and BMS handshake protocol — the tablet chassis does not distinguish between the individual sub-model configurations when negotiating charge state with the ultrabook keyboard base.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Helix 2 unit, monitoring BMS communication, charge acceptance, and cutoff thresholds. The cell accepted full charge and responded correctly to BIOS power management queries throughout.
• Post-install calibration on the Helix 2: After fitting this cell, run one full discharge until the system hibernates at its low-voltage cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after a cell swap on ThinkPad hardware.

BIOS reporting battery health as poor after fitting the new cell

ThinkPad firmware reads EEPROM data embedded in the battery's BMS to assess cell health. When a new cell is installed, the EEPROM values don't match the BIOS's accumulated charge history from the old cell, so the system flags the battery as degraded. This is a firmware calibration issue, not a fault with the replacement cell. Run one full discharge-to-hibernate cycle followed by a complete uninterrupted charge — this forces the BIOS to rewrite its battery learn data against the new cell's actual characteristics.

Helix 2 shutting down at 20–30% charge shown on screen

When the Helix 2 runs at full load — display on, Wi-Fi active, CPU under sustained demand — the battery must deliver current at a higher rate than at idle. A worn original cell hits a voltage cliff under this load, dropping below the BIOS cutoff threshold while the fuel gauge still reads 20–30%. The fuel gauge IC calculates percentage from a charge-count model, not live voltage, so the two diverge. After installing this replacement cell, run two full calibration cycles to synchronise the fuel gauge IC with the new cell's actual discharge curve.