Kejian Jaundice Meter KJ-8000 Compatible Battery 4.8V 500mAh

Kejian Jaundice Meter KJ-8000 — 4.8V Ni-MH Replacement Battery (2/3AAS4)

This is a 4.8V, 500mAh Ni-MH replacement battery for the Kejian KJ-8000 jaundice meter. The KJ-8000 is a non-invasive bilirubin screening device used in neonatal and clinical settings to detect hyperbilirubinemia. It matches the OEM part number 2/3AAS4 and fits directly into the KJ-8000 battery compartment.

• KJ-8000 compatibility: The KJ-8000 runs a 4.8V Ni-MH cell pack — four series cells at 1.2V each. This replacement matches that voltage rail and cell format exactly. The BMS in the KJ-8000 does not require a proprietary handshake, so the meter accepts this cell pack without pairing steps.
• Bench tested on actual hardware: We ran this pack through a full charge-discharge cycle on the KJ-8000 bench unit. The BMS accepted the cell, the power-on self-test completed without fault flags, and the meter advanced to operational mode normally.
• Post-installation self-test protocol: After fitting this battery, let the KJ-8000 complete its full power-on self-test without switching it off mid-sequence. The device runs a BMS verification at startup. Interrupting that sequence before it finishes causes a battery fault flag that sticks until the next clean reboot cycle.

Why the KJ-8000 flags a battery fault on a fully charged new cell

The KJ-8000 charge IC applies a conservative acceptance threshold calibrated to a conditioned OEM cell. A new Ni-MH pack fresh out of packaging has not yet completed its first full electrochemical cycle, so its internal resistance reads slightly outside the meter's expected range. The BMS interprets this as a marginal or faulty cell rather than a new one. One full charge-discharge cycle normalises the cell's internal resistance profile, and the fault clears on the subsequent startup.

KJ-8000 not powering on after the replacement cell sat in storage

Ni-MH cells self-discharge at roughly 1–3% per day under typical storage conditions. If the replacement battery sat unused long enough, the pack voltage can drop below the KJ-8000's BMS recovery threshold — typically around 4.0V for a 4.8V nominal pack. When the meter sees a voltage that low on startup, it interprets the pack as failed and refuses to boot rather than attempt a deep-discharge recovery. Place the battery in a Ni-MH compatible charger externally until the pack reaches at least 4.4V, then reinstall and power on.