MetOne Lasair III 5100 Replacement Battery 14.4V 7800mAh

MetOne Lasair III 5100 — 14.4V Li-ion Replacement Battery

This 14.4V, 7800mAh lithium-ion battery replaces the internal pack in the MetOne Lasair III 5100 portable particle counter. The Lasair III 5100 is used in cleanrooms and healthcare facilities to monitor airborne particulate levels for environmental compliance. Voltage and capacity match the original specification exactly.

• Lasair III 5100 platform fit: The 5100 runs a fixed 14.4V battery rail tied to its internal sampling pump and optical counter circuitry. The BMS on this platform handshakes with the charge IC at startup — any voltage mismatch outside tolerance causes an immediate low-battery flag before sampling begins.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the Lasair III 5100 platform. The BMS accepted the cell, completed its verification sequence, and the device reached full operational status without fault codes.
• Post-swap startup protocol: After installing this battery, let the Lasair III 5100 complete its full power-on self-test without interruption. The device runs a BMS verification loop at boot — cutting power during this sequence triggers a battery fault flag that persists until the next clean reboot, even on a fully charged pack.

Why the Lasair III 5100 flags a battery fault on a freshly charged replacement

The Lasair III 5100 BMS compares cell chemistry signatures against stored OEM thresholds during its startup verification. A new replacement cell has not yet completed a full charge-discharge cycle, so its internal resistance profile sits outside the learned baseline. The device interprets this as a degraded or incompatible pack and raises a battery fault. Running one full charge-discharge cycle before clinical use brings the cell's resistance profile into the expected range and clears the flag on the next boot.

Charge indicator not reaching 100% on first charge after installation

On first charge, the Lasair III 5100 charge IC applies a conservative current limit to an unrecognised cell — this is normal behaviour and not a fault with the battery or charger. The charge IC uses a reduced rate until it logs at least one complete cycle, which causes the indicator to plateau below 100% and trigger a premature charge-complete signal. Charge the battery fully, run the device through one normal sampling session, then recharge to 100%. After this conditioning cycle, the charge IC recalibrates its endpoint and the indicator reaches full on subsequent charges.