CTX NB8600 Replacement Battery 10.8V 6600mAh Li-ion

CTX NB8600 / SmartBook V — 10.8V Li-ion Replacement Battery (DR202 / ME202BB)

This is a 10.8V 6600mAh (71.28Wh) lithium-ion battery for the CTX NB8600 and SmartBook V notebooks. It replaces OEM part numbers DR202, EMC36, ME202BB, NL2020, and SMP02. If your original cell no longer holds a usable charge, this is the direct swap.

• NB8600 and SmartBook V compatibility: Both models share the same 10.8V battery rail, connector pinout, and BMS handshake protocol — one cell fits both. The EEPROM embedded in this pack carries the rated chemistry data the BIOS expects to read at first boot after installation.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the NB8600 platform. The BMS communicated correctly with the system, reported state-of-charge accurately after calibration, and held voltage above the low-battery shutdown threshold through to hibernate-cutoff.
• First-cycle calibration on the NB8600: After fitting this cell, run one full discharge down 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 battery health as poor immediately after fitting the new cell

The NB8600 BIOS reads health data from the battery's EEPROM on first connect. The old cell's degraded charge history is cached in firmware and doesn't automatically clear when you swap the pack. The BIOS flags the new cell as poor because it's still comparing against stale data. Run one full learn cycle — discharge to hibernate, then a complete uninterrupted charge to 100% — and the health status will update correctly.

Laptop shuts down abruptly at 20–30% charge shown on screen

This is a voltage cliff issue, not a capacity problem. Under combined CPU and display load, the cell voltage drops faster than the fuel gauge IC can recalculate — the system hits its hardware undervoltage cutoff before the displayed percentage reaches zero. It happens most often in the first few cycles before the gauge IC has calibrated against the new cell's actual discharge curve. Two to three full discharge-to-hibernate cycles will tighten the fuel gauge accuracy and push that abrupt cutoff point down below 10%.