Datex Light 896895 Compatible Battery 13.2V 3000mAh Ni-MH

Datex Light 896895 — 13.2V Ni-MH Replacement Battery (125-00-444900234)

This is a 13.2V, 3000mAh Ni-MH replacement battery for the Datex Light 896895 patient monitor. It restores portable operation when the original cell degrades, covering transport and continuous bedside monitoring. Voltage and capacity match the OEM specification at 125-00-444900234.

• Light 896895 platform fit: The 896895 monitor runs a 13.2V rail — that is ten Ni-MH cells in series. The connector pinout and BMS handshake are matched to this cell count, so the device firmware reads charge state correctly without re-programming.
• Bench tested on actual hardware: We cycled this battery through charge and discharge under the 896895's typical monitoring load. The BMS reported state-of-charge accurately across the full cycle, and the protection circuit held cutoff at the expected low-voltage threshold without tripping prematurely.
• Post-swap self-test protocol: After fitting this battery, allow the 896895 to complete its full power-on self-test without interruption. The device runs a BMS verification routine at startup — cutting power during this sequence can lock in a false battery fault that persists until the next complete reboot.

Why the Light 896895 alarms low battery immediately after a confirmed full charge

The 896895's BMS stores a charge-state model calibrated to the OEM cell's internal resistance profile. A new replacement cell has a slightly different resistance signature, so the BMS underestimates state-of-charge on the first cycle and triggers the low-battery alarm before actual depletion. This is a calibration gap, not a fault with the battery. Running one complete charge-to-discharge cycle lets the BMS update its model. After that first cycle, the alarm behaviour returns to normal and the charge indicator reads accurately.

Charge indicator stalls below 100% on first charge

On a fresh Ni-MH cell, the charge IC in the 896895 applies a conservative current limit while it measures the new cell's temperature rise and delta-V signature. This causes the display to stall — typically between 85% and 95% — during the first charge session. The cell is not defective; the charge controller is completing its initial characterisation pass. Let the charge cycle run to natural termination without unplugging. After one full charge, subsequent cycles will reach 100% on the indicator at the correct rate.