Extech VPC300 Video Particle Counter Replacement Battery 7.4V 1200mAh

Extech VPC300 Video Particle Counter — 7.4V Li-ion Replacement Battery (VPC-BATT)

This is a 7.4V 1200mAh Li-ion replacement battery for the Extech VPC300 Video Particle Counter with built-in camera. It fits the VPC300 directly, restoring power to the particle detection and video documentation functions. Capacity matches the OEM VPC-BATT specification at 8.88Wh.

• VPC300 platform fit: The VPC300 runs its particle sensor array, optical counter, and camera module from a single 7.4V rail. This pack matches that rail voltage and the connector pinout so the instrument's power management circuit sees no mismatch on startup.
• Bench tested on actual hardware: We ran the pack through sensor initialisation and a sustained particle-counting session. The BMS held voltage stable through the camera activation spike and did not trip during the combined sensor-plus-display draw cycle.
• Post-installation calibration step: After fitting a new pack, run a full calibration cycle through the VPC300 instrument menu before field deployment. The instrument maps battery state during calibration — skipping this causes premature low-battery warnings to appear before the first real measurement session ends.

BMS lockout after the VPC300 sat unused in a carry case for months

Li-ion cells self-discharge during storage. If the VPC300 was packed away with a partially depleted battery, the cell voltage can drop below the BMS recovery threshold — typically around 2.5V per cell. At that point the protection circuit opens and the instrument shows no charge response at all, even on a known-good charger. Apply charge for 15–30 minutes through the OEM charger before attempting to power on; most packs recover once voltage climbs back above 3.0V per cell.

VPC300 shuts down mid-measurement with the battery indicator still showing charge

This is a voltage-sag event, not a capacity failure. Under sustained sensor load — optical counter running, camera active, display at full brightness — current draw is enough to pull cell voltage below the BMS cutoff threshold briefly, triggering a shutdown even though the indicator read partial charge seconds earlier. A degraded cell with high internal resistance sags faster than a fresh one under the same draw. Fit the new pack, run the calibration cycle, then check that the instrument menu shows a stable voltage reading above 7.0V during an active counting session.