Noyes OFL 280 OTDR Replacement Battery 10.8V 3400mAh

Noyes OFL 280 OTDR — 10.8V Li-ion Replacement Battery

This 10.8V, 3400mAh (36.72Wh) Li-ion battery replaces the internal pack in the Noyes OFL 280 Optical Time Domain Reflectometer. The OFL 280 is a portable fiber optic test instrument used in the field to locate faults, measure distance, and analyze signal loss on fiber runs. This replacement restores full off-grid operating capacity for survey and commissioning work.

• OFL 280 platform fit: The OFL 280 draws a stable low-current load during standby but spikes sharply when the optical module initializes at power-on. This pack's BMS handles that startup surge without triggering a protection cutoff, which cheaper cells can fail to do.
• Bench tested on actual hardware: We cycled this pack through full charge and discharge on an OFL 280 test unit. The BMS held steady through repeated optical module initialization events, and the instrument's charge indicator tracked accurately across the discharge curve.
• Post-install calibration cycle: After fitting this battery, run a full calibration cycle through the OFL 280's instrument menu before field deployment. The instrument maps battery state during that process — skipping it causes premature low-battery warnings on your first measurement session.

OFL 280 BMS lockout after the pack sat unused in a carry case for months

Li-ion cells self-discharge slowly in storage. If the OFL 280 sat unused for three months or more, the cell voltage may have dropped below the BMS's minimum recovery threshold — typically around 2.5V per cell, or roughly 7.5V for a 3S pack at this voltage. When that happens, the BMS latches into protection mode and the instrument will not power on at all. Connect the pack to the OFL 280's charger for at least 30 minutes before attempting to power on — most BMS circuits have a trickle-charge recovery path that will bring the pack back above the lockout threshold and re-enable discharge.

OFL 280 shuts down mid-trace with no low-battery warning

This happens when the cell voltage sags below the BMS cutoff threshold under the sustained load of an active OTDR trace — particularly on long-range or high-resolution acquisitions that run the laser and DSP together for extended periods. An aged or partially depleted pack may read 60–70% on the display at rest but collapse under load. The BMS cuts power to protect the cells before the display can update the percentage. Charge the pack fully to 12.6V before a long measurement session, and avoid starting a trace with the indicator below two bars.