Novker AUA800 Replacement Battery 3.7V 4000mAh

Novker AUA800 Series — 3.7V Li-Polymer Replacement Battery (20031019344)

This 3.7V, 4000mAh lithium-polymer pack replaces OEM part 20031019344 in Novker field survey and test instruments. It fits the AUA800, AUA900A, AUA900D, NK3200D, and several additional models in the same family. Capacity is 4000mAh (14.8Wh) — matched to the original specification.

• AUA800 and AUA900 series compatibility: These models share the same 3.7V single-cell architecture, connector pinout, and BMS handshake protocol. The NK3200D runs the same voltage rail, so one pack covers the full platform without modification.
• Bench tested on actual hardware: We cycled this pack through probe initialisation events and sustained sensor logging loads. The BMS held stable across cold-start current spikes and did not trip under the combined draw of sensor power and display backlight.
• First-use calibration on Novker instruments: 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 on the first measurement session.

BMS lockout after a Novker instrument sat unused in a carry case for months

Li-polymer cells self-discharge slowly in storage. If the pack drops below roughly 2.5V per cell, the BMS enters a protective lockout and the instrument will not power on or show any charge indicator. A standard charger connected to the instrument may not recover the pack because the charger handshake expects a minimum cell voltage before initiating current flow. To recover, apply a low-rate pre-charge directly to the battery contacts at 0.1C until cell voltage climbs above 3.0V, then resume normal charging through the instrument.

Readings resetting or dropping out mid-logging session

This is not a capacity problem — it is a voltage sag event. Under sustained sensor load, an aged or partially discharged cell can dip below the instrument's undervoltage threshold for a fraction of a second, which triggers a data-logging reset or display flicker. A new pack at full charge holds its voltage flatter under load. If the symptom continues after fitting a fresh pack, check that the battery contacts on the instrument are clean and making full surface contact — resistance at the connector amplifies voltage drop under load. Target a resting cell voltage of at least 3.7V before starting a long logging session.