About this replacement
Lenovo Yoga L390 / ThinkPad L380 — 11.1V Li-Polymer Replacement Battery (01AV482)
This 11.1V, 3950mAh (43.85Wh) lithium-polymer cell replaces the original battery in the Lenovo Yoga L390, ThinkPad L380, ThinkPad S2 Yoga 2018, and the ThinkPad Yoga L380-20M7001BGE, among over 220 additional variants. It fits the same physical bay and uses the same multi-pin connector as the OEM unit. Part numbers 01AV482, L17M3P55, and SB10K97626 are all covered by this cell.
- L380 and L390 platform fit: These models share a common battery bay geometry, connector pinout, and BMS handshake protocol across the L380 and L390 board revisions. The BIOS reads the same EEPROM data structure regardless of which board variant you're running, so the cell seats and registers without modification.
- Bench tested on actual hardware: We cycled this cell on a ThinkPad L380 unit, monitoring charge acceptance and BMS communication at each stage. The protection circuit handled full charge termination and low-voltage cutoff cleanly, with no dropped connections across the data pins during discharge.
- Post-install calibration on the L380/L390: After fitting this cell, run the laptop down to hibernate-cutoff on battery alone — no sleep, screen on — then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.
BIOS reporting poor battery health immediately after fitting a new cell
The ThinkPad BIOS stores charge history and health metrics in the old cell's EEPROM. When a new cell goes in, that data is gone, and the firmware flags the battery as degraded because it has no cycle history to read. This is not a fault with the replacement cell — it is the BIOS reacting to a blank slate. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% gives the firmware enough data to rebuild its health estimate. After two or three full cycles the reported health figure will normalise.
Laptop shutting down at 20–30% shown on the fuel gauge
The fuel gauge IC calibrates against the old cell's voltage curve, not the new one. When the L380 or L390 hits a load spike — CPU burst plus display at full brightness — cell voltage drops faster than the gauge expects, and the system interprets it as a hard low-voltage event and shuts off. The displayed percentage at cutoff is wrong; the cell is hitting its actual voltage floor earlier than the gauge predicts. Force two full discharge cycles to hibernate-cutoff to let the gauge IC map the new cell's curve. After calibration, shutdowns should not occur above approximately 3.2V per cell under normal load.