Testo HHR-200AB27 Fluegas Analyzer Replacement Battery 6V 2000mAh

Testo Fluegas Analyzer — 6V Ni-MH Replacement Battery (HHR-200AB27)

This is a 6V, 2000mAh Ni-MH replacement battery for the Testo Fluegas Analyzer. It fits the combustion exhaust gas measurement instrument used in HVAC and industrial flue gas testing. Voltage and capacity match the original HHR-200AB27 specification exactly.

• Fluegas Analyzer platform fit: The Testo Fluegas Analyzer draws a stable low-current load during most of a measurement session, but spikes sharply when the probe module initialises. This pack's BMS handles that initialisation surge without tripping — the cell configuration and protection thresholds match what the instrument expects on startup.
• Bench tested on actual hardware: We cycled this pack through probe-on and probe-off sequences, including O2 sensor warm-up draws. The BMS held steady through each initialisation spike and maintained voltage within the instrument's operating window throughout the sustained logging load.
• Post-install calibration step: After installing, run a full calibration cycle through the instrument menu before field deployment. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings during your first measurement session, even with a fully charged pack.

BMS lockout after the analyzer sat unused in a carry case for months

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. After several months in storage, the pack voltage can drop below the BMS recovery threshold — typically around 4.5V for a 6V Ni-MH pack — and the BMS enters a lockout state to prevent cell damage. In lockout, the charger sees no response and the instrument will not power on. Connect the pack to the Testo charger and leave it for at least 90 minutes; most BMS circuits recover once the charger applies a low-current wake pulse above 4.5V total pack voltage.

Readings reset or drop out mid-logging session with no low-battery warning

This happens when the sustained current draw from multiple active sensors — O2, temperature, and combustion efficiency running simultaneously — pulls pack voltage below the instrument's reset threshold before the battery indicator flags a problem. The voltage sag is momentary but enough to interrupt the data stream. It is more common with a pack that has aged cells or was not fully charged before deployment. Charge the pack to full, confirm the green charge indicator on the Testo charger before disconnecting, and run the calibration cycle before the next session.