Nihon Kohden ECG-9130K 12V Replacement Battery LCT-1912ANK

Nihon Kohden ECG-9130K / Cardiofax Series — 12V Sealed Lead Acid Replacement Battery (LCT-1912ANK)

This is a 12V 2300mAh (27.6Wh) sealed lead-acid replacement battery for the Nihon Kohden ECG-9130K electrocardiograph and compatible Cardiofax-series devices. It supplies the internal power rail that keeps the ECG running during portable cardiac monitoring when mains power is unavailable. Voltage and chemistry match the OEM specification exactly.

• Cardiofax and ECG-9000/9100 series compatibility: These models share a common 12V SLA power architecture with the same physical footprint and connector orientation. The BMS handshake expects a sealed lead-acid cell at this voltage — substituting a lithium pack triggers a permanent fault condition.
• Bench tested on actual hardware: We ran charge-discharge cycles on the ECG-9130K platform and confirmed the BMS accepts the cell, completes charge termination correctly, and does not throw a battery fault code during the device self-test sequence.
• Post-installation self-test protocol: After fitting this battery, let the ECG-9130K complete its full power-on self-test without interruption. The device runs a BMS verification routine at startup — cutting power during this sequence stores a false battery fault that persists until the next clean reboot cycle.

ECG-9130K not completing boot sequence after battery swap

A freshly installed SLA cell arrives at a partial state of charge from storage, typically between 12.4V and 12.6V open circuit. The ECG-9130K boot sequence includes a voltage threshold check — if the cell sits below the device's minimum start voltage, the unit stalls mid-boot and displays a power fault. Charge the battery fully before first installation and verify open-circuit voltage reaches at least 12.6V before fitting. If the device still stalls, the cell may have deep-discharged in transit — place it on a standalone SLA charger at 0.2C until it recovers to 12.6V, then reinstall.

Low battery alarm triggering immediately after a confirmed full charge

The ECG-9130K BMS calibrates its state-of-charge reading against the discharge curve it observed on the previous cell. On a new battery, the BMS has no learned curve yet and defaults to a conservative low-battery threshold that can trip within minutes of a full charge. This is not a faulty battery — it clears after one complete charge-discharge cycle under normal device load. Run the unit through one full session on battery until it signals low, recharge fully, and the alarm threshold recalibrates. Do not use the device clinically until this first cycle is complete.