About this replacement
Dell Latitude X200 — 7.4V Li-ion Replacement Battery (1K090)
This 7.4V, 3600mAh (26.64Wh) Li-ion battery replaces the original cell in the Dell Latitude X200 ultraportable notebook. It matches the OEM voltage rail and connector used in that chassis. OEM part numbers covered include 1K090, 0K630, BAT-X200, 1J749, 451-10213, 8U443, 2K184, 0K619, and 312-0058.
- Latitude X200 cell compatibility: The X200 chassis uses a slim 7.4V two-cell pack with a specific BMS handshake tied to Dell's BIOS power management layer. Swapping to any other voltage or pack format triggers a hardware warning at POST. This cell matches that handshake, the physical dimensions (211.80 × 50.18 × 15.85mm), and the original connector orientation.
- Bench tested on actual hardware: We ran this cell through charge, discharge, and re-seat cycles on the X200. The BMS communicated correctly with the system board — no unidentified device flags at POST and no forced AC-only mode triggered during the test.
- First-cycle conditioning on the X200: 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 battery health as poor after replacement on the Latitude X200
The Latitude X200 BIOS reads health data from EEPROM registers embedded in the original battery pack. When a new cell goes in, those registers are blank or show factory defaults that don't match Dell's expected charge history signature. The BIOS interprets this as a degraded or unknown cell and flags poor health even though the cell is new. Running one full discharge-to-hibernate then a full uninterrupted charge clears this — the BIOS battery learn cycle writes new baseline data and the warning clears on next boot.
Latitude X200 shutting down at 20–30% charge shown on the OS gauge
This happens because the fuel gauge IC is still calibrated against the old cell's voltage curve. The new cell hits a voltage cliff under combined CPU and display load at a point the IC reads as 20–30% remaining. The laptop cuts power before the gauge reaches zero. Fix this by running two to three full discharge-to-hibernate and full charge cycles — the fuel gauge IC recalibrates against the new cell's actual curve. After calibration, the gauge reading and the real cell voltage should align to within a few percent at the 3.0V per cell floor.