About this replacement
Lenovo ThinkPad E450 — 10.8V Li-ion Replacement Battery (45N1752)
This is a 10.8V 4400mAh (47.52Wh) Li-ion replacement battery for the Lenovo ThinkPad E450 series laptop. It covers a wide range of E450 configurations including the 20DC003WUS, 20DC004CUS, and Edge E450 i7-5500U variants. OEM part numbers 45N1752 through 45N1757 all apply to this cell group.
- ThinkPad E450 series fit: These models share the same 10.8V three-cell architecture, physical connector pinout, and BMS handshake protocol. A single cell replacement covers all variants without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an E450 chassis. The BMS accepted the cell, reported state-of-charge correctly after calibration, and held voltage under combined CPU and display load without tripping the protection circuit.
- First-cycle calibration on ThinkPad E450: After installing, run one full discharge to hibernate-cutoff, 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 ThinkPad firmware.
BIOS reporting battery health as poor after replacement on ThinkPad E450
ThinkPad firmware stores battery learn data tied to the previous cell's EEPROM profile. When a new cell goes in, the BIOS compares the new cell's characteristics against that stored data and flags a mismatch as poor health. This is a firmware state, not a defect in the replacement cell. Running one complete discharge-to-hibernate followed by a full uninterrupted charge gives the BIOS enough data to rewrite the learn cycle. After two to three cycles, the health indicator normalises.
Laptop shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The OS reads an outdated discharge profile and misjudges remaining capacity — the cell hits its real voltage floor before the gauge catches up. Under combined CPU and display load, the voltage drop is steep enough to trigger an immediate shutdown. The fix is two to three full discharge-and-charge cycles; after that, the gauge IC maps the correct floor voltage and the shutdowns stop.