About this replacement
Clevo W251EL Series — 11.1V Li-ion Replacement Battery (6-87-W15ES-4V4)
This is an 11.1V, 4400mAh (48.84Wh) lithium-ion replacement battery for the Clevo W251EL and W251ELQ notebooks, as well as Zoostorm B980 and 7872-9043/A models. It replaces OEM parts including 6-87-W15ES-4V4, 6-87-W15ES-4YP, VNB142, W240BAT-6, W240BUBAT-3, and W240BUBAT-6. If the original cell has degraded or stopped holding a charge, this is the direct swap.
- W251EL and Zoostorm B980 compatibility: These models share the same 11.1V battery bay, six-cell configuration, and BMS handshake protocol — which is why a single part number covers all of them. The connector pinout and charge communication line are identical across the platform.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on W251-series hardware. The BMS negotiated correctly with the charging circuit, current tapered as expected at the top-of-charge threshold, and no protection trips occurred under sustained CPU and display load.
- Post-swap calibration on the W251EL: 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 this platform.
BIOS reporting poor battery health immediately after fitting a new cell
The W251EL stores capacity and health data in the EEPROM of the old battery pack. When a new cell goes in, the BIOS compares the new cell's reported data against the stored history and flags a mismatch as poor health. This is a data problem, not a cell problem. Running one full discharge-to-hibernate then a clean 100% charge lets the system rewrite its baseline. After one or two cycles the health indicator updates correctly.
Laptop shuts down at 20–30% charge shown on the W251EL
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The OS reads a percentage based on old learned data, so the displayed figure and real cell voltage drift apart. When the cell hits its true low-voltage cutoff — around 9V under combined CPU and display load — the system shuts off even though the gauge still shows charge remaining. Run two full discharge-to-hibernate cycles followed by uninterrupted charges to 100%, and the gauge IC re-anchors to the new cell's curve.