About this replacement
NIKKISO PSK-01 — 6V Ni-MH Replacement Battery
This is a 6V 2000mAh (12Wh) Ni-MH replacement battery for the NIKKISO PSK-01 portable suction pump. The PSK-01 is used in clinical settings for airway clearance and secretion removal. This cell matches the original voltage and chemistry the device BMS expects.
- PSK-01 battery platform: The PSK-01 runs a 6V Ni-MH chemistry specifically because its charge IC and BMS thresholds are calibrated to the voltage curve of nickel-metal hydride cells. Substituting a different chemistry would cause the device to misread state-of-charge and trigger false alarms.
- Bench tested on actual hardware: We ran a full charge-discharge cycle on the PSK-01 platform and confirmed the BMS accepted the new cell without fault flags. The charge IC applied a conservative current limit on the first cycle — this is normal Ni-MH conditioning behaviour, not a cell defect.
- Post-swap self-test protocol: After installing this battery, allow the PSK-01 to complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup — cutting power during this window causes a false battery fault that persists until the next clean reboot.
PSK-01 low battery alarm triggering immediately after a confirmed full charge
The PSK-01 BMS compares the new cell's resting voltage against a threshold set for a conditioned OEM cell. A fresh Ni-MH replacement has not yet established the internal resistance profile the BMS uses to calculate capacity. The device interprets this mismatch as a low-capacity fault and raises the alarm even when the cell is at full charge. One complete charge-discharge cycle resolves this — the BMS updates its reference point and the alarm clears. Do not place the device in clinical use until this cycle is complete and no alarm flags remain.
PSK-01 failing to power on after the replacement battery sat in storage
Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A cell that has been in a warehouse for several months can drop below the PSK-01's BMS recovery threshold — typically around 5.4V for a 6V pack — and the device will not boot. Connect the charger and leave it for a full charge cycle before attempting power-on. If the charger's LED does not indicate charging activity within 10 minutes, the cell voltage may be below the charger's own detection floor — disconnect, wait 5 minutes, and reconnect to allow the charge IC to re-attempt detection.