About this replacement
Lenovo Legion 5 Pro 16IAH7H — 15.44V Li-Polymer Replacement Battery (5B11F24156)
This is a 15.44V, 5100mAh (78.74Wh) Li-Polymer battery for the Lenovo Legion 5 Pro and Legion 5 series gaming notebooks. It fits the Legion 5 Pro 16IAH7H, 16ARH7H, Legion 5 15IAH7H, and over 140 additional Legion variants sharing the same power rail and connector. OEM part numbers covered include 5B11F24156, 5B11F24161, L21C4PC1, L21D4PC1, and L21M4PC3.
- Legion 5 and 5 Pro series fit: These models share a common 15.44V four-cell Li-Polymer architecture, the same ZIF connector pinout, and a unified BMS handshake protocol. Any variant in this family running the same voltage rail accepts this cell without modification.
- Bench tested on actual hardware: We ran this cell through charge-discharge cycles on a Legion 5 Pro chassis. The BMS negotiated correctly, charge termination triggered at full capacity, and no fault codes appeared on either the EC or BIOS battery page.
- Legion BIOS learn cycle after swap: After fitting this battery, run the laptop down to hibernate cutoff on battery alone, then charge uninterrupted to 100%. This resets the BIOS learn cycle against the new cell chemistry and clears the false "poor health" or inaccurate capacity warning that appears after every cell replacement on Legion hardware.
Legion shutting down at 20–30% shown after battery swap
Under full CPU and discrete GPU load, the Legion platform draws hard on the battery. A freshly fitted cell has an uncalibrated fuel gauge IC, so the reported state-of-charge does not match actual cell voltage. When real voltage hits the EC's low-voltage cutoff threshold — around 13.5V under load — the system shuts down even though the gauge still shows 20–30%. Two full discharge-to-hibernate and uninterrupted recharge cycles recalibrate the gauge IC and align the reported percentage with true cell voltage.
BIOS reporting battery Wh as wrong after replacement
The Wh figure the BIOS displays is read from EEPROM data embedded in the battery's BMS, not calculated live from the cell. A replacement cell may carry EEPROM values from a slightly different production batch, causing the system info page to show a Wh rating that does not match the label. This is a data field mismatch, not a capacity fault. The actual usable energy the cell delivers is unchanged — the displayed figure is cosmetic and does not affect charging or discharge behaviour.