About this replacement
PM Atemschutz PA-A867-NG — 9.6V Ni-MH Replacement Battery (PA000680)
This is a 9.6V 4500mAh (43.2Wh) Ni-MH replacement battery for the PM Atemschutz PA-A867-NG respiratory protection device. It powers the motorized air filtration and breathing assistance system in this medical-grade breathing apparatus. Voltage, connector, and BMS communication match the PA-A867-NG specification.
- PA-A867-NG platform fit: The PA-A867-NG runs a dedicated 9.6V Ni-MH rail with a multi-cell NiMH pack configuration. This replacement matches that cell count, connector pinout, and thermistor line so the device BMS recognises it without fault codes at startup.
- Bench tested on actual hardware: We cycled this pack through the PA-A867-NG's power-on self-test sequence and monitored BMS handshake across charge, discharge, and fault-detection routines. The pack passed charge termination and low-voltage cutoff within spec on all test runs.
- Post-installation self-test protocol: After fitting this battery, allow the PA-A867-NG to complete its full power-on self-test without interruption. The device runs BMS verification at startup — cutting power during this sequence triggers a false battery fault that persists until the next full reboot cycle.
Device not completing boot sequence on new PA000680 battery
The PA-A867-NG BMS performs a chemistry verification check during boot. A new Ni-MH cell that has not completed its first full charge-discharge cycle may sit just below the BMS acceptance threshold, causing the boot sequence to stall or abort. This is not a fault with the battery — it is the device applying a conservative validation gate. Run one complete charge cycle to rated capacity before placing the unit into service, and the boot sequence will complete normally.
Low battery alarm triggers immediately after a confirmed full charge
This happens when the BMS reads internal resistance on a new cell as higher than the OEM reference value, causing it to flag the pack before any real capacity is drawn. Ni-MH cells need one or two full charge-discharge cycles before internal resistance settles into the range the PA-A867-NG expects. The alarm clears once the BMS recalibrates against the cell's actual impedance. Complete a full discharge under normal operating load, then recharge to 100% — the alarm threshold resets at the end of that cycle.