Drager PAC 6000 Replacement Battery 3.6V 2700mAh 8326856

Drager PAC 6000 / PAC 8500 Series — 3.6V Li-SOCl2 Replacement Battery (8326856)

This is a 3.6V 2700mAh lithium-thionyl chloride cell that replaces OEM part numbers 8326856, 8326186, and LBT0100. It fits the Dräger PAC 6000, PAC 6500, PAC 8000, and PAC 8500 portable single-gas monitors. These instruments run on a non-rechargeable Li-SOCl2 primary cell — not a lithium-ion pack.

• PAC 6000 / 6500 / 8000 / 8500 platform: All four models share the same battery cavity dimensions and the same 3.6V supply rail to the electrochemical sensor and display circuits. The connector keying and cell format are identical across the range, so one part number covers the whole family.
• Bench tested on actual hardware: We confirmed correct voltage output at 3.6V open circuit and monitored the cell under sensor initialisation load. The cell held stable voltage through the pump motor start and sensor warm-up without tripping the instrument's low-voltage cutoff.
• Calibration before field deployment: After fitting this cell, run a full calibration cycle through the PAC's instrument menu before taking it into a confined space or hazardous area. The PAC maps battery state during calibration, and skipping that step causes the instrument to throw premature low-battery warnings during the first real monitoring session.

Voltage passivation layer on Li-SOCl2 cells — what it does to a freshly installed PAC

Li-SOCl2 cells form a thin lithium chloride layer on the anode when stored. On a new or long-stored cell, this passivation layer creates a brief voltage dip the moment the PAC powers on and draws current. In a healthy instrument that dip recovers within seconds, but a PAC that has been calibrated on a depleted old cell may interpret that initial dip as a near-dead battery. Running the calibration cycle burns through the passivation layer and lets the instrument baseline correctly against the cell's true capacity at 3.6V.

PAC shows "Battery Low" or shuts off within seconds of power-on with a new cell installed

This is the passivation effect described above, not a faulty cell. The instrument's low-voltage threshold fires before the passivation layer clears. Power the PAC on, let it run through its start-up self-test, then immediately enter the calibration menu — sustained current draw during calibration clears the layer fast. If the instrument still cuts out before calibration completes, measure the cell voltage under load with a multimeter: a genuine good cell will recover above 3.4V within 10 seconds of contact.