Chem 5580 Notebook Replacement Battery 10.8V 6600mAh DR202

Chem 5580 / 6800 / ChemBook 5400 — 10.8V Li-ion Replacement Battery (DR202)

This is a 10.8V, 6600mAh Li-ion battery for Chem notebook computers including the 5580, 6800, and USA ChemBook 5400 series. It replaces OEM part numbers DR202, EMC36, ME202BB, NL2020, and SMP02. Capacity is 71.28Wh — matching the original cell specification.

• 5580, 6800, and ChemBook 5400 compatibility: These three models share the same 10.8V battery rail, connector pinout, and BMS communication protocol, which is why a single cell covers all three. The EEPROM on the new cell carries the correct rated Wh data the BIOS expects to read during POST.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the 5580 platform. The BMS handshake completed without fault flags, and the protection circuit tripped correctly at both the high-voltage cutoff during charge and the low-voltage cutoff before deep discharge damage.
• Post-install calibration on the 5580: After fitting this cell, run one full discharge to hibernate cutoff — let the laptop shut itself down, not a manual power-off. Then charge uninterrupted to 100%. This forces the fuel gauge IC to re-learn the new cell's actual capacity curve and clears the inaccurate health warning the BIOS displays after every cell swap.

BIOS reporting battery health as poor after replacement on the 5580

The BIOS reads health data from the battery's EEPROM — a small memory chip that stores cycle count, rated Wh, and charge history. When a new cell arrives, its EEPROM counters are at factory defaults, which the BIOS may flag as a mismatch against the old cell's logged data. This is not a fault with the new battery. Run the full discharge-to-hibernate then uninterrupted charge cycle once, and the BIOS battery learn cycle will update its reference data and clear the warning.

Laptop shuts down at 20–30% remaining after battery swap

This happens because the fuel gauge IC is still calibrated to the old cell's discharge curve. The new cell hits a voltage cliff — where output voltage drops sharply under combined CPU and display load — at a different point than the old cell did. The OS reads that voltage drop as near-zero charge and triggers an emergency shutdown, even though the percentage shown looks comfortable. Run two full discharge-to-hibernate and full-charge cycles back to back, and the fuel gauge IC will map the new cell's actual voltage curve correctly.